Diana Coman, PhD, “Lucian Blaga” University of Sibiu, Romania Narcisa Vrînceanu, PhD, “Lucian Blaga” University of Sibiu, Romania There are numerous… [310368]

CHAPTER I. [anonimizat], “Lucian Blaga” [anonimizat], PhD, “Lucian Blaga” [anonimizat] “greening” [anonimizat], meaning to ennoble the items by functionalization (Carvalho & Santos; Parisi et al., 2015). [anonimizat], [anonimizat], biopolymers or other medical vegetal resourced components with applicable potential onto fibrous polymeric supports. Thus, [anonimizat], [anonimizat]. (Joshi et al.,2009; Eralp et al., 2016).

Other previous studies and researches belonging to the authors support the alternative of natural dyes onto different fibrous polymeric supports (Coman et al., 2013; Coman et al., 2015; Coman et al., 2015). Coloration with natural extracts is a sustainable alternative. [anonimizat] (CSA) [anonimizat]-linking method. The study proved an efficient grafting onto the surface of polymeric supports. [anonimizat], being used in scientific medication of atopic dermatitis (AD) (Chi-Leung Hui et al., 2013).

The present research plays a [anonimizat] a co-assisted investigation complex system.

The review relies on original outcomes of natural extracts application on different fibrous polymeric substrates.

The monograph is a review of the most relevant experimental research activities performed during the running of the project entitled “[anonimizat]-textiles”. The present review is highlighting the original outcomes derived from the published papers achieved as a consequence of experimental data acquiring.

[anonimizat] a [anonimizat], performance, by a comparative utilization of some biomordants and a [anonimizat]/protection/activity envisaging the development of clothing garments designed to human health.

[anonimizat], by employing of both some inclusion compounds and biomordants. In fact the review is an extension of ecologic dyeing with complementarity on the antioxidant activity/anti-inflammatory response/behavior of the studied extracts.

The study reflects the constant concerns of authors regarding the relevant biocidal response of bioactive components of extracts with synergic effects for dyeing aspect.

In this monograph we have initialized a research oriented to traditional extraction techniques.

The disadvantages of these techniques rely on: mass transfer protection for the reason of the entanglement of more system phases (Carvalho& Santos, 2015), time consuming. Additionally, the long duration of the process varies on the high energy consumption and diffusion rates of solvents through the pores of the materials (Parisi et al., 2015). Another major drawback of the conventional extraction procedure is linked up to the high temperatures and severe pressures that can destroy the active molecules and damage the quality of the extract (Joshi et al., Eralp et al.,2016; Coman et al., 2013; Coman et al., 2015; Coman et al.,2015). A mechanical approach of the extraction should be avoided due to its poor efficacy.

Chemical extraction, using a huge quantity of organic solvents, has a major and hazardous impact on both human beings and the environment (Chi-Leung Hui, et al., 2013).

Consequently, the rationale of this research was given by the identification of an improved extraction methodology, namely ultrasonication assisted extraction (UAE) that can increase the percentage of active parts from the plant cell wall. Basically, UAE is explained by the acoustic cavitations provided by ultrasonic sounds and mass transfer to the solvent.

The active molecules were extracted from green nut shells, using a green water-solvent extraction system by refluxing/UAE, for at least two hours. The dyeing methodology assumes the use of dye extract and biomordants, such as citric acid and tannic acid by comparison with a classic mordant. The retention time of the juglone extracted from walnut shells was performed by comparison with the retention duration of synthetic juglone.

The methodology we proposed in this study is added value know-how, having the following advantages:

Minimum alteration of the active molecules;

operation in semi-aqueous extraction since the organic solvents were in some measure alternate with safe ones, compressing the extraction duration.

The ultrasound extraction is a must for a sustainable development, being more economic than the traditional processes (Chi-Leung Hui et al., 2013).

Another contributing response of this study has as key point the difference regarding the crystal or particle structure, during their using: a pigment maintains its structure, while the colorant loses it, by solving in a solvent system. Consequently, the research

There are numerous researches associated to the “greening” of textile polymeric supports through the utilization of bioactive extracts, as well as establishment of Antimicrobial potential, meaning to ennoble the items by functionalization (Carvalho C& Santos, 2015). In order to enhance the products competitiveness, and in the same time from environment protection reasons, numerous researches have been developed regarding the using of antimicrobial active agents, as well as natural colorants, biopolymers or other medical vegetal resourced components with applicable potential onto fibrous polymeric supports. Thus, active substances, like chitosan and Aloe Vera extracts, Eucalyptus essential oils have been used onto cellulosic and chemical supports, etc. (Joshi et al.,2009; Eralp et al.,2016).

Other previous studies and researches belonging to the authors support the alternative of natural dyes onto different fibrous polymeric supports (Coman et al., 2013; Coman et al., 2015; Coman et al., 2015). It is well-known that dyeing with natural extracts is a sustainable alternative.

Reliable after effects of natural extracts application on different fibrous polymeric supports were achieved, gathering analysis of the most relevant coloristic/chromatic attributes by a comparative utilization of some biomordants and a classical one for ecologic dyeing of textiles, as well as highlighting of the antimicrobial/protection/activity envisaging the development of clothing garments designed to human health. The novelty of the studies stresses the bactericidal performance of bioactive components of natural extracts (black currant and green walnut shell). In fact the study is an extension of ecologic coloring with complementarity on the antioxidant activity/anti-inflammatory response/behavior of the studied extracts. The study reflects the constant concerns of authors regarding the relevant biocidal response of bioactive components of extracts with synergic effects for coloration aspect.

The element of novelty, namely the preserving of the colorant molecule derived from walnut shells (juglone), even under its aqueous extraction conditions. Moreover, the extraction yield is relatively high.

The impact of this study consists of the application of natural extracts on polymeric supports natural/active, by investigating the mechanisms, the essence being a sustainable, innovative laboratory experiment of natural dye extraction from dried nut shells and dyeing of wool and polyamide (PA) polymeric substrates assisted by biomordants.

The juglone (5-hydroxy-1,4-naphtalen-dione), is recognized as a natural colorant, meaning a mixture of phenols and quinones (Fig. 1) (CLSI: Clinical and Laboratory Standards Institute, 2010).

Fig. 1.1: The rings of phenol and quinone (A, B) depicted in atoms arrangement within juglone molecule (Coman et al.,2015)

Juglone can be extracted from walnut shells (Juglans regia). Its application in silk, polyamide (PA), etc is widely known.

Considering the expanded concern for health and environment, “green” dyed polymeric matrices are sharing more reputation, pointing out to the enhancement of their aggressiveness in marketing (Ibrahim et al.,2010; Vankar & Shanker, 2009).

Since the evenness of colored polymeric matrices essentially confides in the ability of preparatory processes, diverse researches with reference to solvent used on different polymeric matrices have been performed.

However by identifying innate constraints, these methods are not feasible on the market (Morshed, 2010). The low dyeing capacity of flax fiber with natural extracts was yielded (Guo et al., 2000).

The particular sense of the coloring obstacle was high crystallinity parameters belonging to the vegetable fiber and the lower rate of dye-uptake resulting from the poor permeation of the dye molecules into the fibre. To surpass this problem, a number of studies regarding different modifications have been carried out in order to improve the levels of dye dye-fiber interaction (Kamel et al., 2009; Kamel et al., 2011; Vankar et al., 2007). In addition, a lot of studies reported that modifying the flax fiber via the inclusion of quaternary ammonium groups, epoxy quaternary ammonium salt, or graft polymerization with acrylonitrile, N-hydroxymethyl acrylamide, could remarkably enhance the dyeability of the vegetable fibre.

Our survey is an endeavor to merge the benefits of surface functionalization of polymeric supports by grafting and their coloring with plants’ anthocyanin extracts, by testing conventional and non-conventional methods (ultrasounds).

Owed to its dominant attribute to react with the hydroxyl groups of cellulose through its anchor group (monochlorotriazinyl), monochlorotriazinyl-cyclodextrin (MCT-CD) interfered.

Based on the dyes’ selectivity, some reports described the capability of hydrophobic MCT-CD’s nanocavity host to design inclusion complexes (Vončina & Le Marechal, 2005; Crini, 2008; G. Crini et al., 2007; Sivakkumar, 2008; Norasiha, 2011; Norasiha et al., 2009; Cannava et al., 2008).

In the direction of facilitate the graphs reading, the notation MCT-CD has been used, which derives from cyclodextrin, i.e. monochlorotriazinyl-cyclodextrin (MCT-CD). They can be described as having toroid architecture with hydrophobic core and hydrophilic shell, with hydroxyl groups detected on them (Klein et al.,2000).

Likewise, the inclusion aggregate of MCT-CD aids the insertion/diffusion of the natural dye, altering the extent to which the diffusion shows up within the polymeric matrix. The host-guest synergy of MCT-CD was proved by relevant utilization in the textile field. The reaction below shows the functionalization of polymeric supports with MCT-CD:

For the researches gathered in this book-review, we have preferred red onions as a consistent source of anthocyanin pigments for textile dyeing. Firstly, the scope was to examine the enhancement mechanism of dyeing strength of flax through graft polymerization treatment by using MCT-CD. The methods of bath and ultrasound-coloring were used to dye the lignocellulose supports.

Due to the necessity of imposing safety and environmental standards, many studies have been done on natural dyes covering textile applications, but extension of coloring matters is still growing. Today, coloration processes based on natural sources should be investigated with more responsibility, to make industrial application possible. Successful commercial use of natural dyes for any particular fiber-natural dyes system needs adequate investigation (Ibrahim et al., 2010; Vankar& Shanker, 2009). Previous studies have been extended, using other natural extracts less studied in eco-friendly textile dyeing. The main result and characterizing aspect of the research consists in highlighting an innovative and successful encapsulation of natural dyes for obtaining "green fabrics". Moreover, speed up the diffusion of dye inside the previously functionalized bast fibers and the colorfastness was enhanced at blackberry than to bilberry extract.

There is a significant interest in re-introducing natural coloring into current technical production scale for textile coloration, by improving product quantity and reducing environmental impact. Due to the necessity of imposing safety and environmental standards, many studies have been done on natural dyes covering textile applications, but the extension of coloring matters is still growing.

Today, coloration processes based on natural sources should be investigated with more responsibility so to make industrial application possible. Successful commercial use of natural dyes for any particular fiber-natural dyes system needs adequate investigation. The use of different types of biomordants with their natural origin and their biodegradability replaces metal based mordant, thus making natural dyeing more eco-friendly. Metal ions in fixing reagent will affect the human health and aggravate the difficulty of waste processing (Ibrahim, et al., 2010; Vankar& Shanker, 2009). A previous study of our team showed that using MCT-β-cyclodextrin in the functionalization of different textile supports as well as the development of a stable inclusion complex, having as guest molecule the anthocyanin natural colorants, enhanced the durability of fabrics against washing and friction.

Subsequently, previous research was extended, by using other natural extracts less studied in ecofriendly textile dyeing. The main result and characterizing aspect of the research consists in highlighting an innovative and successful encapsulation of a natural dye (the blackberry extract) into a modified cyclodextrin in order to obtain "green fabrics". The basic principles of this assertion is that the surface modification of the polymer fibers like grafting with MCT-ß-CD can enhance hydrophilicity and, first of all, inclusion complex forming ability to immobilize dyes, pigments, etc. Moreover, using the ultrasounds dyeing method, a speed-up in the diffusion of dye inside the previously functionalized bast fibers was achieved and the colorfastness was enhanced.

Natural coloration of textiles can greatly enhance the appearance and attractiveness of products, increase global concern about environmental and health safety and improve their market competitiveness.

The utilization of coloration potential of textiles with natural products is an innovative alternative of dyeing process, often used for artisanal practice for handicrafts, paintings and handloom textiles (Kumar& Pritti, 2009).

Grafted cyclodextrins on textile substrates can be used to obtain special functionality of textiles such as absorption; they can complex and release products like bioactive substances, vitamins, drugs or dyes (Voncica &Vivod, 2013).

Previous researches on natural dye extracts (Coman et al., 2013) have improved and extended the analysis, the authors using amarena (bitter) cherries extract, applied onto lignocellulose support grafted with ß-cyclodextrin.

The evaluation and characterization of the samples imposed specific measurements of morphology and structure, as well as fastness tests of natural color applied onto textile material.

Biomedical textiles with special properties and added functionalities are the target that the European textile industry has required.

Silver, polyhexamethylene biguanide, quaternary ammonium compounds are among the active agents these items are using as broad-spectrum biocides. Properties like, effectiveness and durability depend on the type of fabric, the biocide and the finishing method used in the system. These attributes envisage the clean technology/methodology for textiles, industry competitiveness and cleaner technological strategies.

Natural dyes not only contribute to the quality of the textile materials that protect body against common infections, but also keep the environment clean. Thus, the anthocyanins used in our study are polyphenolic pigments conferring the dominant color diversity in plants. Being harmless and water soluble makes them interesting for use as natural water soluble colorants.

Their main attributes could be summarized as it follows:

– stability: explained/quantified by the extrapolation of the results acquired in vitro with model solutions of pigments obtained through plant extraction or laboratorial synthesis;

– antioxidant activity, which is known to play a vital role in the prevention of neuronal and cardiovascular illnesses, cancer, and diabetes (Guesmi et al.,2011).

Behavior of anthocyanin is expressed in terms of molecular interactions of the chromophore units with parts of the pigments themselves and/or with some constituents of the plant cell. Having extensive range of colors occurring widely in nature, they consist of natural colorants. Nevertheless, their use has been limited because of their relative instability and low extraction, despite the great potential of applications that anthocyanin represent for many industries like: food, pharmaceutical, and cosmetics. That is why, there is a lot of investigators engaging in solving the issues that are associated with isolation and stability of anthocyanin, as well as washing fastness. This is the idea that generated our study. It is aiming at carrying out a systematic study of the CD initial treatment of cellulosic materials onto dyeing properties (crystalinity and fastness).Numerous papers have described the selection of natural raw materials, dyeing procedures, shade of dyeing and fastness properties (Shown et al., 2009). In this article, anthocyanin from bilberry fruits (Vaccinium myrtillus) has been extracted by an advantageous traditional technique. The supernatant resulted from centrifugation using hydro alcoholic solution at low temperature of the extracts was used for dyeing experiments on cellulose fabrics. The research performed up to the present, revealed the fact that in case of small natural and synthetic anthocyanin, the common α-, β-, and γ-cyclodextrins cannot accommodate bigger, highly substituted pigments. However, our study is a preliminary trial in hosting natural dye molecules in β-cyclodextrin microcavities. Howbeit these results, it is not impossible to imagine that greater macrocycles will be able to preferentially accommodate the colored flavylium or quinonoidal forms, thus favoring their persistence in model solutions. Despite this fact, our research succeeded in emphasizes the effectiveness of β-cyclodextrin in colour stabilization on textile. β-CD has an ability to form complex with variety of molecules including natural dye. The properties of cyclodextrins enable them to be used in a variety of different textile applications. β- Cyclodextrin has already been used as a low environmental impact additive in dyeing processes (Savarino et al., 2004). Efficient initial treatment of the textile fibres with ß-cyclodextrin, temperature, pH and addition of electrolytes can influence the uniformity of their dyeing (Cireli& Yurdakal, 2006). CD plays the role of host in the formation of both soluble and solved crystalline inclusion complexes with large variety of non-covalently included guest molecules (Toneli, 2007). Nevertheless, rather than conducting to color counteraction, these compounds diminish the anthocyanin visible absorption band, as resulted from our study.

Another main objective of our study was the dyeing stabilization effect due to the assistance of β-cyclodextrin at a process of graft polymerization of the textile support; the results were compared then with that of a standard dyeing. Relevant enhancements of colour stability and depths were noticed in case of β-cyclodextrin assisted dyeing, as compared to dyeing process without β-cyclodextrin. The role of ß-cyclodextrin consisted in increasing of wash and rubbing fastness, as well.

The methodology approach of the present study consists in: a covalent fixation of the water-soluble ß-cyclodextrin (CD) blocked into polymeric matrices surfaces by a polycondensation reaction under specific conditions. The grafting arose over the forming a crosslink between hydroxyl groups of cellulose and CD polymer, aspect endorsed by FT-IR spectra (Shown& Murthy, 2009); an advantageous, safe and simple technique of anthocyanin extraction; a method to stabilize the natural dye onto the cellulosic textile materials, using β-CD, in terms of washing and rubbing fastness; an eco-friendly process for natural dyeing of cellulose fabrics using bilberry fruits in conjugation with cyclodextrin as graft polymerization agent, will interest both manufactures and consumers in the continuing replacement of synthetic dyes.

Research and innovation programs advanced both by academic institutions and private companies continue to aim at studies regarding herbs derived biologically active compounds, because of their health-promoting properties. Epidemiological studies demonstrated a specific interaction between a regime prosperous in flavonoids derived from fruits and vegetables and a scaled down hazard of cardiovascular diseases and cancer (Gabr, 2010).

In recent years, anthocyanin as most important bioactive belonging to flavonoid class, have drawn increased consideration, taking into account research that has been performed on anthocyanin pigments with respect to their numerous favorable fallouts for human health and their utilization as potential added-value ingredients.

Anthocyanin are water-soluble vacuolar plant pigments answerable for the bright colors red, purple or blue of flowers, skin, seeds, fruits and leaves. They appear essentially in herbs in different concentrations and compositions banking on genetic and environmental causes. Structurally, anthocyanins consist of anthocyanidine, which an aglycon part (see Figure 1.2), carbohydrate debris and possibly acylating groups.

The biological attributes of an anthocyanin is ruled by its appropriate chemical structure, the most important studied effects being the antioxidant activity.

In order to evaluate the chemical structure-biological activity relationship, the qualitative and quantitative analysis of anthocyanin from different plant materials become an important task. The nourishing sources of anthocyanin from tastyherbs belong in particular to the families, like: Vitaceae (grape), Rosacea (cherry, plum, strawberry), Saxifragaceae (red and black currants), Ericaceae (blueberries), Solanaceae (eggplant), and Cruciferae (red cabbage). Stable anthocyanin under acidic and neutral conditions is found more abundantly in flowers than in fruits.

Several analytical techniques were used to investigate anthocyanin, to identify, quantify and potency testing. The first step in anthocyanin analysis consists in the optimal extraction of pigments, either by traditional (maceration in safe solvents at low temperature) or modern separation technologies, like different types of extraction: solvent extraction, pressurized liquid extraction or supercritical fluid extraction. Quantitative analysis of anthocyanin can be done either by spectrophotometric techniques – the most used method for testing anthocyanin extracts being the pH differential method as industry standard methods (various Pharmacopea, AOAC Official Method for determination of monomeric anthocyanin in fruits juices, beverages, natural colorants, wines), or by HPLC methods, which are more specific and fit-for-purpose for determination of individual pigments. Although academic research developed different modern techniques, most laboratories continue to test fruits and vegetables by UV-VIS spectroscopy for total anthocyanin despite HPLC proved to be more specific.

As a result of their pharmacological properties, anthocyanin have for long been used for therapeutic purposes. As these pigments are very important in food colors, further development of anthocyanin which provides improved stability, stabilization and longer storage time allows large applications of these bioactive compounds in food industry. Application of the HPLC-MS technique in order to evaluate the copigmentation reactions of anthocyanin in foods contributed to the evaluation of parameters of these processes. Other interesting applications of anthocyanin refer to their use as natural dyes in textile dyeing, applications in cosmetic industry and their use as indicators in acid-base titration. Anthocyanin extracts from red cabbage were used for obtaining an acid base indicator paper (Hueseyin 2006).

The present review is focused toward the assessment and comparison of total monomeric anthocyanin in red cabbage samples from different Romanian geographical regions by using spectrophotometric methods, in the perspectives of potential applications of these extracts, either as antioxidant phytoproducts, dietary supplements, or natural food and textile colorants.

Textile producers are showing the raising concern in the utilization of lasting incenses to polymeric textile matrices as well as skin softeners. The assets of natural dyes are as follows:

they are eco-friendly/eco compatible;

they do not conceive any environmental issues in the phase of their obtaining or us;

they keep an ecological harmony.

As a function of climate, some plants played the role of sources for natural dyes. (Carpignanoet al., 2010; Lubbe &Verpoorte, 2011; Kadolph & Casselman, 2005; Sarkar & Seal, 2003; Ustun et al., 2004).

Plants and fruits are traditionally sources of natural dyes used to color textiles, some of them being presented in Table 1.1 (Lubbe & Verpoorte, 2011).

Diverse circumstances, such as: pH, temperature, light, presence of co-pigments, self-association, metallic ions, enzymes, oxygen, ascorbic acid, sugar alter the color and cohesion of these compounds. In this regard many investigations have been polarized to augment the security of these compounds (Kadolph & Casselman, 2005; Sarkar & Seal,2003; Ustun et al., 2004).

Our explorations stressed the potency of β-cyclodextrin in color counteraction on textile since it possesses the capacity to form inclusion compounds with a diversity of molecules including natural dyes.

Functional textiles and garment add formal properties, such as: appearance, social recognition, interest, cold resistance, easy-care, likewise new features and responses of thermo conducting, restraint of obnoxious odors, antibacterial and antifungal stability. Novel bioactive treatments oriented toward polymeric matrices render novel performances (Khanna, 2006; Popa et al., 2003; Schindler& Hauser, 2008).

The polymeric matrices’ action coupled with the bioactive endurance is a synergic effect between bond type from the bactericidal item and polymeric fiber on one hand, and chemical essence of the antibacterial agent.

By virtue of quick advance, novel antimicrobial components and enhanced polymers, like copper and silver compounds, chitosan, triclosan, quaternary ammonium compounds, polymeric phosphonium salts, polymeric biguanides, N-halamin compounds and antibiotic drugs were studied (Dring, 2003; Qaziasgar & Kermanshahi, 2008; Perepelkin, 2005; Worley& Sun, 1996).

Granting with antimicrobial resources, polymeric matricescan has mainly two functions: resistance of polymeric matrices against pathogenic microorganisms and curing/prophylactic.

Endurance and attainment of novel attributes activated into polymeric matrices assess the performance of the antimicrobial treatment.

Micro-encapsulation/inclusion is an upcoming technology that textile manufacturers are looking to keep ahead of the competition and challenged to find innovative materials that provide benefits The encapsulation and enclosing techniques are used in wide range of features, including medical and cosmeto-textiles, phase change materials, thermochromic and photochromic dyes, antimicrobial and deodorizing finishes, flame retardant finishes, chemical protection, etc (Butuc et al., 2007; Landy et al., 2012).

The rationale of our book was the idea that textile coloration should be performed according to environmental standards, as well as finding of some sustainable solutions in terms of dyeing stability when using natural extracts.

There are a lot of methods to improve dyeing properties of cellulosic supports;

the positively charged ions;

the inclusion of quaternary ammonium groups. Polymeric matrices thus changed contribute to more powerful attraction for anionic dyes and pigments;

corona plasma technology.

As an ecological safe option/alternative to metallic salts, which very much modify the color, the fiber cross linking with polycarboxylic acids can be adopted for the enhancement of specific features of polymeric matrices, counting wet tensile and compressive strength. The mordanting with citric acid as an assisting agent is recommended (Surina et al., 2008).

Cyclodextrins are natural molecules borrowed from starch, possessing an impressive ability to design inclusion complexes (microencapsulation) in solution or in solid state with organic molecules, mainly aromatics, through host/guest interaction. There are a lot of studies, demonstrating their role of textile finishing agents, being grafted onto flax fabrics.

Previous researches assumed that the adsorption dynamics merges both the inclusion complex resulting from the presence of MCT-ß-CD and physicochemical interactions (Crini, 2003; Landy et al., 2012).Thus, the book gathers the efficiency of the two promoters of a stable and sustainable natural dyeing with black cherry extract, meaning: CA and MCT-ß-CD. It is well-known that by inducing the self-catalyzed esterification of cellulosic hydroxyl groups, citric acid (CA) crosslinks the cellulosic fibers. Moreover, it strengths the chemical bond between natural dye and fiber.

Since the cyclodextrins possess hydrophobic cavities in which a number of chemicals can form inclusion complexes, they can be regarded as an alternative to conventional dyeing. Consequently, all these aspects provides the novelty of our studies included in this book and relying on the maintenance of natural textile dyeing given the enclosing technique by an inclusion complex,

Regarding the methodology, the dyeing of the textile samples was approached in two manners: the encapsulation/inclusion of dye into the CD molecule as grafting agent for flax fiber and classic dyeing using mordants, such as citric and tannic acids. The same authors reported the use of black cherry extract, with efficient outcomes, like positive values of abrasion strength.

CHAPTER 2. EXPERIMENTAL PART

Diana Coman, PhD, “Lucian Blaga” University of Sibiu, Romania

Narcisa Vrinceanu, PhD, “Lucian Blaga” University of Sibiu, Romania

RESEARCH PROCEDURE

Materials supports and chemical reagents

The samples used in all studies were:

washed and white bamboo with yarns fineness of 34/1 Nm,

polyamide 100% with a weight of 67g/m2 washed-degreased

11 type woolen fibers based supports.

100% bast textile supports

flax fabrics

wild black cherry

extract of amarena cherries

black currant fruits and green walnut shells extracts

Red onion (Allium cepa) samples

anthocyanin extract from blackberry (Rubus spp.) fruits

The juglone (5-hydroxy-1,4-naphtalen-dione), a very well-known natural colorant, is a mixture of phenols and quinones. Juglone can be extracted from walnut shells (Juglans regia). The standard juglone powder was acquired from Sigma Aldrich.

biomordants like citric acid (CA) and tannic acid (TA), in comparison with a standard mordant copper sulphate CuSO4).

alcoholic extracts of black currant and nut shells, and 3 and 5 % mordant.

bacterial strains: Staphylococcus aureus ATCC 29213 (Gramm positive) and Pseudomonas aeruginosa ATCC27853 (Gramm negative).

Mueller Hinton agar culture medium

24 hours bacterial cultures with a 0,5 Mac Farland Standard microbial density equivalent (1,5 x108 cells)

Solvent: ethanol, methanol

Acetonitrile (HPLC grade) and disodic phosphate were bought from Fluka Company.

acetone percentage in mobile phase (50%)

PBS (phosphate buffered solution)

0.1 % HCl acidified ethanol 80 % solution

MCT- β-cyclodextrin

Na2CO3

Epibromohydrin and 1,2-Diaminoethane (C1)

HClO4 solution in DMF

Fmoc–NH– CH2CH2–NH2 and triethylamine in DMF

triethylamine in DMF

Ac2O in DMF

Twill 100% flax supports, having each dimensions like 3 cm × 3 cm; the yarn has the fineness of 40/2 tex and specific mass of 200 g/m2

MCT-β-CD (CAVAMAX®, Wacker Chemie AG).

Ethanol (from Chemical Company) for analytical purposes.

Specifications and descriptions of the samples (Tables 2.1 and 2.2)

F-Reference bast fibers support;

L-MCT-ß-CD- Linen polymeric material functionalized with Monocholoro-Triazynyl-ß-Cyclodextrin;

sample 1-Reference sample colored using the standard dye-fiber interaction method, (1% blackberry extract);

sample 2-Functionalized linen fibers matrix colored using the conventional dye-fiber interaction method (1% solution of blackberry extract);

sample 3-Non-functionalized linen fibers matrix colored using the non-conventional method by using ultrasounds (1% solution of blackberry extract);

sample 4-Functionalized linen fibers matrix treated by a non-conventional method using ultrasounds (1% solution of blackberry extract);

Table 2.1. The variants of flax fabric samples for experimental investigation (Coman, et al.,2014)

Table 2.2. Denominations and characterization of the prepared specimens (Coman et al., 2014)

Specifications and descriptions of the samples: L-Reference linen fibres support; L-ß-CD-Grafted support with ß-CD; sample 1-Non-functionalized support dyed (1% bilberry solution); sample 2-Functionalized linen fibers support dyed (1% bilberry solution); sample 3-Non-functionalized support dyed (2% bilberry solution); sample 4-Functionalized linen fibers support (2% bilberry solution); sample 5-Non-functionalized support dyed (1% blackberry solution); sample 6-Functionalized support dyed with 1% solution of blackberry; sample 7-Non-functionalized support dyed (2% solution of blackberry); sample 8-Functionalized support dyed (2% solution of blackberry).

2.1. Laboratory extraction methodologies

Black currant fruits and green walnut shells extraction

2.1.1. Extraction of juglone from walnut shells (Juglans regia)

Aqueous extraction

When dealing with compounds of low solubility, it is compulsory to extract them from a solid mixture. In this case, for colorant identification, a Soxhlet extraction can be performed.

The walnut shells are weighted. The technique is performed in glassware placed in-between a flask and a condenser, forming the Soxhlet extractor set-up. The basics of the technique consist of the washing of the solid by means of a solvent, extracting the desired compound into the flask. A quantity of 0.05-0.2 g was immersed into the thistle of the Soxhlet extractor, and a mixture of solvents water/ethanol was employed. An important condition was to maintain the temperature of the device just below the solvent boiling point. In order to extract all the inner compounds from the dried walnut shells, a number of solvent cycles during two hours were run. The aqueous solution was filtered and evaporated, in order to obtain a dried residue. This residue was solved in acetronitrile and used for the analyses in HPLC (High Performance Liquid Chromatography) system.

Ultrasound (UE) extraction

UAE has been conducted by combination of grounded and dried samples of green walnut shell in methanol. After that the sample was situated in an ultrasounds chamber, for an interval of 30 minutes. The parameters of the ultrasound chamber are: 20 Hz frequency and distinct powers (100-500 W), within the time range of 15-120 minutes. Initially, the extraction temperature was established at 20- 40°C and after two hours it rose up to 50°C. The reiteration of the extraction was made up, until all the extract was collected. The solvent system was ethanol (EtOH) and water. 50 mL of bisolvent system were immersed in an Erlenmeyer flask of 250 mL containing 20 g walnut shells. The Erlenmeyer flask was covered with a thin film of alumina to prevent the evaporation of the solvent. The parameters, like power and temperature were fixed at level 5, and 25-30°C, respectively within a 1-2 hour extraction interval. In order to elude a rising of temperature above 30°C, we proceed to periodical replacement of water from the container with cold one (below 15°C). The filtration of the extract was made with Whatman filter paper, followed by the collection of the solution. The procedure was repeatedly conducted, and then the extracts resulting from the twice-UAE extraction were mixed up. It can be assumed that the UAE technique is more selective than the conventional one.

The experimental dyeing protocol and the colour differences measured by reflexion spectrophotometry, can be associated with the juglone quantity, as well as the textile substrate the extracts were applied on.

2.1.2.Onion extract – Sonicator dyeing method

The immersion of the specimens was made in the dye extract solution into the Elmasonic E cleaner bath. The parameters of the apparatus are as follows: frequency of 38.5 kHz and power of 50 W. Confrontational the previous studies, in order to experience low to high values of ultrasounds volumes, a new item was attached. This modification changes the water and dye molecules’ vibrational energy. It is well-known that dye molecules consist of ions and molecules. The important role playing by the ultrasounds is to dissociate the dye molecules in ions. It is a major factor that determines the collision of dye molecules with fibres, which is the acceleration of the ions through the dye solution. The parameters of the ultrasonic assisted dyeing were like: liquor ratio of 1:30, the treatment duration was between 15 and 30 minutes, at a temperature of 30°C. Depending on the material weight, the extract concentration was set-up at 2%.

The ultrasonic volumes ranged from low to high. The coactive fallout attained from ultrasonic dyeing methodology and biomordant enhanced both the dye uptake and fastness coordinates of dyed polymeric matrices with lower temperature. After a few laboratory experiments, an optimization of the dyeing was reached, meaning 80 minutes as well as an averaged value of sonic volume, and a dyeing temperature of 30șC.

2.2. Pre-treatment of polymeric supports

2.2.1. Pre-treatment of the linen supports

The experimental protocol of graft polymerization (padding-squeezing-drying- curing) dwelled in:

curing in an exicator for 24 hours;

impregnation bath with a 100 g/l concentration of MCT-ß-cyclodextrin and 30 g/l for Na2CO3 containing 10-50 g/l of MCT – β-cyclodextrin;

drying at room temperature for 12 hours;

curing at 80÷160°C for a range time1÷15 minutes);

washing with distilled water;

air drying.

2.2.2 Pretreatment of fabrics (flax fabric graft polymerization)

The experimental protocol of grafting (padding-squeezing-drying-curing) consisted as follows: curing in an exicator for 24 hours; preparedness of impregnation bath (100 g/l concentration of MCT-ß-CD and 50 g/l Na2CO3; drying at room temperature for 12 hours; curing at 90÷170°C for different periods of time (1÷15 minutes), for graft polymerization performing; washing with tap hot and cold distilled water, up to pH=6,5-7;air drying.

2.2.3. Grafting of flax fibre support (Procedure of MCT-β-CD initial treatment of flax fibres)

The graft polymerization treatment was carried out at a liquor ratio of 1:10 with MCT-β-CD and Na2CO3

The treatment consisted in the following phases:

– impregnating the fabric with MCT-β-CD (100 g/L ) and Na2CO3 (25 g/L ) solution (x/4, x is the amount of MCT-β-CD) for 2 minutes, followed by a padding stage at a squeezing ratio of 135%; the conservation in an exicator was performed on a Benninger (Switzerland) type padder, at a speed of 50m/min, hydro-extraction pressure of 0.5 bars, level of liquid extraction of 150%, temperature of 20 șC, width of 1200 mm;

– drying for 10 minutes at 80 °C (on Mesdan Lab Dryer);

– curing (using a Mesdan Lab Dryer) at 160 °C for 7 minutes;

– repeated hot (90 °C) and cold washing up to pH = 6.5-7 to remove the reaction products;

– drying at room temperature (22 °C) for 72 hours.

The samples were thoroughly rinsed with water and dried.

2.2.4. Pretreatment of fabrics (flax fabric grafting)

The experimental protocol of grafting (padding-squeezing-drying- curing) consisted in the following stages: curing in an exicator for 24 hours; preparation of impregnation bath having a 100 g/l concentration of MCT-ß-CD of and 50 g/l for Na2CO3; containing 30 g/l of MCT- β-cyclodextrin; drying at room temperature for 12 hours; curing at 90÷170°C for different periods of time (1÷15 minutes), for graft polymerization performing; washing with tap hot and cold distilled water, up to pH=6,5-7; air drying;

2.2.5. Initial treatment of cellulosic matrices

The experimental graft polymerization consisted in the following stages:

– curing in an exicator for 24 hours, initial weighting of samples, preparation of ß- CD and alcalin catalysts (NaOH și Na2CO3) solutions, preparation of padding bath having a 100 g/l concentration of ß-CD of and 50 g/l of Na2CO3;

– immersion of cotton matrices in a solution having 10-50 g/l of monochlortriazinyl β-cyclodextrin; the pH was fixed to 4 by using acetic acid, at room temperature for 30 minutes;

– padding to 100% pick-up;

– drying at room temperature for 12 hours;

– curing at 90÷170°C for distinct time spans (1÷15 minutes), according to the experimental planning, for grafting performing;

– thoroughly washing with tap hot and cold distilled water, up to pH=6,5-7;

– air drying.

Laboratory dyeing protocols

2.3.1. Exhaustion coloring/dyeing

Black currant fruits and green walnut shells extracts, as well as biomordants such as citric acid and tannic acid were employed in the laboratory dyeing protocol. The comparison was made with a standard mordant, meaning copper sulphate (CuSO4). The composition of the dyeing bath relies on: the alcoholic extracts of black currant and walnut shells, and 3 and 5 % mordant (Coman et al, 2016).

The treatment of the specimens (wool, polyamide and bamboo textile supports) consists of their immersion in an Elmasonic E Ultrasonic, model S10H, with a cleaning bath having a capacity of 0.8 L. It sizes 190 x 85 x 60 mm. Previously the samples were treated with mordant agents at a temperature of 30șC for a duration of 30 minutes, at a liquor ratio of 1:50. Afterwards the immersion of the studied specimens was performed in the dye extract.

The study used the dye-fiber interaction method, the dyeing bath consisting of black currant and walnut shell extracts, adding the mordant, in order to stabilize the natural pigment, all the quantities being established to the studied polymeric support (woolen, polyamide, or bamboo).

Dyeing procedure of cellulosic matrices

Dyeing solutions contain concentrations at liquor ratio 1:30 and 7.43 mg anthocyanins considered for a solution of 1%; for a solution with the concentration of 2%, the amount of anthocyanin is 14.86 mg; all these amounts represent 148.58%, meaning 148.58g anthocyanin on the amount of fruit used. The cellulose fabrics were dyed with anthocyanin extract, keeping the fabric in dye bath for about 30 minutes at 80°C. The dyed material was washed with a soap solution, cold water and dried at room temperature.

The bast fabrics were dyed with anthocyanin extract, through the exhaustion method, i.e. an immersing of the polymeric matrix in a dye bath for 30 minutes at 60°C. Meanwhile, dyeing using the sonication-assisted procedure was performed.

The concentration of the dyeing solution, in terms of textile material tested is quantified by liquor ratio, which is 1:30, representing 148.68 g anthocyanin with regard to the entire amount of fruit used. The tested material was washed with a soap solution, cold water and dried at room temperature.

The flax fabrics were dyed with black cherry anthocyanin extract, by exhaustion method meaning an immersing of the polymeric matrix in a dye solution for 35 minutes at 60°C. After dyeing, the studied polymeric matrix was washed with cold water and dried at room temperature. Pigments are employed in alkaline pH (11-12) at higher temperature like 80-90°C having a molar ratio of 1:20 for 60 up to 90 minutes. Afterwards, the tested specimens are washed. The soaping is carried out at 60°C for duration of 15 minutes.

The research was focused onto a comparison, in terms of both the efficiency of the natural extract inclusion and stability of the performed treatments. For this reason/purpose, dyeing conditions for both the MCT-β-CD grafted samples and for those dyed with the assistance of a biomordant (Cytric Acid 3% w.p.), were identical.

The experimental protocol dwells in a long lasting liaison onto the polymeric matrices surface of the natural extract over inclusion mechanism.

Dyeing with black cherry extract into the grafting agent-monochlorotriazinyl-β-cyclodextrin (MCT-β-CD).

2.3.2. Onion extract – Bath-dyeing procedure standard dyeing method

For bast supports, the immersion was made in dye solution (approximately 2%.owf) at 60șC and duration of 80 minutes.

For dyeing an Allium cepa anthocyanin extract was employed.

The dyeing of 10 g of flax fabrics parameters were as follows:

Dye bath concentrations were 1 and 2%.

The liquor ratio was 1:30

Dyeing temperature was fixed at 80°Cfor about 30 min.

Higher temperatures are not recommended since they can affect the cohesion of the natural pigments.

Afterwards, a soap solution was used to wash the coloured flax substrates, for a couple of minutes, followed by an air-dried at room temperature.

2.3.3. Ultrasound-dyeing procedure

The ultrasound instrument was an Elmasonic E Ultrasonic cleaner bath, S10H. Its technical characteristics are: 0.8 L capacity, internal dimensions of 190 x 85 x 60 mm; the electrical generator’s frequency is 38.5 kHz and the power is 50 W. In the ultrasonic dyeing bath the concentration of the anthocyanin dye from Allium cepa was 1 and 2%, at a liquor ratio of 1:30, for approximately 15 min, at 30 °C.

CHAPTER 3. NATURAL EXTRACTS

EXTRACTION METHODOLOGIES – CONVENTIONAL AND MODERN TECHNIQUES

Simona Oancea, PhD, “Lucian Blaga” University of Sibiu, Romania

The present chapter represents part of the Habilitation thesis entitled “Development of high-value bioactive products for industrial applications and in life sciences area, with emphasis on natural compounds” of Simona Oancea, 2014, presented at the “Lucian Blaga” University of Sibiu, Romania (http://doctorate.ulbsibiu.ro/obj/documents/7HabilitationThesis_SimonaOancea_REZUMAT.pdf). Results of research activities published in scientific journals in the field, are described.

Phytochemicals represent important chemical compounds, mainly phenolic compounds and their largest class of flavonoids, as well as carotenoids, allyl sulfides, alkaloids, terpenes and indoles, which are widely distributed in plants. They are considered non-essential nutrients but may provide human health-promoting and disease-preventing effects.

Among the class of flavonoids, anthocyanins are water-soluble pigments which display beneficial properties mainly due to their free-radical scavenging properties / antioxidant abilities (Kowalczyk et al., 2003). The wide range of physiological properties and potential applications of such compounds, contributed to the continuous research on this direction.

The analysis of anthocyanins from different plant materials represents an important task for either the development of new valuable products with industrial application or for the estimation of the anthocyanins intake through diet in population or individual groups.

The analytical strategy is based on the optimum extraction of anthocyanins from plant cells, followed by purification if required, and quantitative analysis. The extraction which is closely related to the requirement of gaining the highest amounts and the greatest bioactivity, involves sample size reduction, suitable extraction system and parameters. The analytical strategy is followed by in vitro studies of the biological activity. Selecting the proper techniques for each step becomes crucial when studying the structure-activity relationship (SAR) and the optimization of composition of mixed extracts useful for food, pharmaceutical or cosmetic industry.

A number of conventional (classic, traditional) and non-conventional (modern) extraction procedures have been described for phytochemicals, each of them being subjected to improved optimization by varying parameters such as solvent type, solvent concentration, liquid/solid ratio, time and temperature of extraction. Conventional anthocyanins extraction is carried out frequently in solvents such as acetone or acidified methanolic solutions such as to obtain the stable flavylium cation of red colour (Garcia Viguera et al., 1998; Giusti & Wrolstad, 2001), but drastic evaporation of these solvents may produce partial hydrolysis of acylated anthocyanins (Revilla et al., 1998). More eco-friendly solvents have been used recently, such as ethanol.

Ultrasound-assisted extraction (UAE) and microwave-assissted (MAE) have been applied to different phytochemicals as an economically efficient extraction method (Vinatoru 2001; Ghafoor et al., 2009). Anthocyanins, in particular those from grapes have been subjected to other techniques, such as pressurized liquid extraction (PLE) and supercritical fluid extraction (SPE) (Ju & Howard, 2003; Cox et al., 2001) but with limited success, because these biomolecules are heat-sensitive and water-soluble.

In the investigation of our research group, experimental testing for a proper anthocyanins extraction consists mainly on two methodologies:

1. Cold (cryo) maceration – as conventional method

2. Ultrasound-assisted extraction – as non-conventional method; briefly, vials containing accurately weighed crushed samples mixed with the appropriate solvent were immersed into water in the ultrasonic device, and irradiated for different extraction times, at various solvent/sample ratios, and at different temperatures; more drastic conditions have been applied by using a sonifier with a transducer dipped directly into the sample. The first methodology involves several steps, which are generally presented in Figure 3.1.

Fig. 3.1: General approach for cold maceration to extract anthocyanins from plant

The influence of various factors on stability was determined for red onion samples extracted by maceration as conventional method widely applied in pharmaceutical industry (Oancea & Drăghici, 2013). Red onion anthocyanins are good candidates for nutraceuticals or as eco-friendly dyestuffs for textile industry. For the study of the solvent influence on anthocyanins extracted from red onion (Allium cepa L.), acidified and non-acidified hydroethanolic solution were investigated in the previous mentioned work: ethanol:acetic acid:water (50:8:42); ethanol:acetic acid:water (70:4:26); ethanol:acetic acid:water (80:1:19); 50% ethanol; 70% ethanol and 80% ethanol. Extraction was performed at low temperature. Quantitative analysis of total monomeric anthocyanins (TA) was performed using the pH differential spectrophotometric method. As shown in Figure 3.2, the most efficient extraction solvent was 80% ethanol. Ethanol solution is considered nontoxic solvent which also reduce the pigments decomposition and increase the extraction of anthocyanins in their native form.

Fig. 3.2: The content of total anthocyanins in red onion cv. Red of Turda under different extraction solvents, at 4°C (Oancea & Drăghici, 2013).

The study regarding the evaluation of total anthocyanins and phenolics from red onion bulbs from different Romanian regions showed various concentrations, probably due to genetic factors or the used production, harvest and postharvest practices. The content of anthocyanins in red onions varies according to different environmental conditions (rainfall patterns, temperature, water content of soil). The highest anthocyanins content was found in the dry outer peel parts of red onion than in the edible parts, having the potential for the development of cheap natural ingredients with functional properties for industrial application. The obtained data from such investigation on content of bioactive molecules from indigenous food plants are relevant for nutrition studies regarding the estimation of daily consumption of phenolics/anthocyanins and for completing the national food composition databases.

The type, concentration and elution strength of the solvent which may influence on anthocyanins content was also studied and reported for extracts of blueberry (Vaccinium corymbosum L.) (Oancea et al., 2012). In this investigation, ethanol was selected as extraction solvent with low toxicity instead of other more powerful solvents such as acetone, methanol and diethyl ether, with potential toxicity that may interfere with the final intended purpose of the prepared natural extract for the pharmaceutical and food sector. As presented in Figure 3.3, extraction with ethanol solution appeared more efficient for anthocyanins recovery than that with acidified ethanol. The highest anthocyanin content was found in 50% ethanol extract, while the lowest was obtained with water.

Fig. 3.3: The content of total anthocyanins in blueberries in different extraction solvents, at 4oC (Oancea et al., 2012).

The authors studied also the extraction of anthocyanins from blueberries in 50 % ethanol (v/v) under three different temperatures: 4 oC, 30 oC, and 50 oC, as it is known that high temperature favors the transfer of quality-relevant constituents from the plant material to the crude extract. As presented in Figure 3.4, temperature of 50 oC showed better extraction yields, but temperatures higher than 70 °C drastically affect the recovery of native anthocyanins (Markakis et al., 1957).

As conclusion, the findings of the work indicated a high recovery of anthocyanins from high bush blueberries by using discontinuous extraction in 50 % ethanol solution at 50 °C for 2 hours, using protection against light. These results may become important for food manufacturers because different parameters used during food processing will impact on the content and composition of these bioactive pigments and consequently will influence their functional properties.

Fig. 3.4: The content of total anthocyanins in blueberries at different extraction temperatures in 50 % ethanol (Oancea et al., 2012)

Conventional extractive technologies of anthocyanins from red raspberry, blackberry and sweet cherry fruits have been compared to modern methods, such as ultrasound-assisted extraction (UAE) (Oancea et al., 2013). In the published paper, UAE experiments on red raspberry fruits coming from the spontaneous flora were performed using 70 % ethanol (v/v) and at 20 oC. The obtained results on the appropriate solvent/sample ratio are presented in Figure 3.5.

Fig. 3.5: The content of total anthocyanins (TA) in red raspberry according to different solvent/sample ratio of ultrasound-assisted extraction, at 20oC (Oancea et al, 2013)

The results indicate that 10/1 (v/w) and 15/1 (v/w) should be the appropriate solvent/sample ratios for achieving good anthocyanins UAE extraction yield for short time (15 min). The obtained results on the proper extraction time using the the crude extract prepared for a 10/1 (v/w) solvent/sample ratio are presented in Figure 3.6.

Fig. 3.6:Total anthocyanins (TA) content in red raspberry (Rubus idaeus L.) according to different times of ultrasound-assisted extraction, at 20oC (Oancea et al., 2013).

There was about 15 % improvement in the total anthocyanins content due to the use of longer extraction time (20 min) compared to the other fast extractions through UAE, but a significant decrease in extraction time when compared to conventional extraction. The increase of temperature to 30 oC in a longer time four point UAE experimental run (15 – 45 min) for a solvent/sample ratio of 20/1 (v/w) lead to a decrease of the extraction time in order to obtain high concentration of anthocyanins. The total anthocyanins content in red raspberry crude extracts obtained under UAE experiments was found similar to that obtained by conventional extraction, but extraction time was significantly reduced by approximately seventy-fold. The reduced time of extraction through UAE is particularly favorable for the extraction of these thermolabile compounds.

The overall conclusion from the study is that UAE may find efficient application for extraction of total anthocyanins from red raspberry fruits, as it resulted in similar yields as conventional extraction, but with great reduction of extraction time and at room temperature.

In the same paper other results of the UAE-extraction of anthocyanins are presented for blackberry and sweet cherry fruits. In the experiments, efficient extraction solvent systems were used as follow: 0.1 % HCl in 80% EtOH in case of blackberry cv. Thornfree, and 0.1 % HCl in 60% EtOH for sweet cherry cv. Black Gold. UAE investigation was performed at 30 oC.

Fig. 3.7: The content of total anthocyanins in blackberry cv. Thornfree according to different times and solvent/solid ratio of ultrasound-assisted extraction, at 30 oC, at 200 W ultrasound power (Oancea et al., 2013).

Fig. 3.8: The antioxidant activity by Ferric Reducing Antioxidant Power (FRAP) in anthocyanin crude extract of blackberry cv. Thornfree according to different times and solvent/solid ratio of ultrasound-assisted extraction, at 30 oC, at 200 W ultrasound power (Oancea et al., 2013).

The results have shown that UAE extraction conditions of 0.1 % HCl in 80 % ethanol, with a 10 (v/w) solvent/solid ratio at 30 °C for 5 min were the most suitable for anthocyanins recovery from blackberry, while a 15 (v/w) solvent/solid ratio at 30 °C for 20 min lead to the highest antioxidant capacity as determined by ferric reducing antioxidant power assay (FRAP), the latter probably due to other extracted bioactive constituents under the process conditions. Because anthocyanins are quite unstable, a fast UAE extraction at 30 °C is advised.

Comparing the two types of extraction, conventional and UAE, it may be conclusioned that longer time of maceration may give better recovery of total anthocyanins in some berry fruits such as blackberry, but not in sweet cherry cv. Black Gold. In sweet cherries, the present native enzymes, particularly polyphenoloxidase which are stable also at freezing temperatures (Chaovanalikit et al., 2004) caused anthocyanins degradation in frozen samples. The browning process generated through the action of such enzymes speeds up in the presence of organic acids from these fruits which are their substrate. However, the authors emphasizes on the experimental observation that Black Gold sweet cherry anthocyanins are of lower stability than those in blackberry, and recommends rapid handling for better extraction.

Potential industrial applications of natural extracts

Besides the health benefits provided by anthocyanins, these bioactive compounds have been found other useful industrial applications, such as food supplements, textile dyes, cosmetics, ornamental purpose, and natural pH indicators for chemical industry applications (Vankar, 2010).

The food industry represents the main sector that benefits most from the scientific results regarding the multifunctional properties of natural compounds. For example, powders based on anthocyanins composition from various food plants (grapes, tomatoes, red cabbage) are used as natural food additives in confectionery and soft drinks. Anthocyanins extracted from red cabbage may be used as natural alternatives to synthetic blue colorings for foods with neutral pH being stable over a wider pH range (Bridle & Timberlake, 1997). Anthocyanins extracts from Hibiscus are applied in soft drinks as well as in medicinal herbs.

Research studies have shown an increased efficiency of natural extracts of various herbal origin on lipid oxidation, so that these natural antioxidants have great potential to substitute the synthetic ones used in edible oils industry. Fruit bioactives including anthocyanins also may found future application as meat antioxidants (Karre et al., 2013).

Based on the strong antioxidant properties, tea polyphenols have been incorporated into a wide variety of food products such as juices, cookies, candies, chewing gum, showing good protection against oxidation in oil-in-water emulsions at pH 5.5 (Roedig-Penman & Gordon, 1997), antidiscoloring properties on beta-carotene (Unten et al., 1997) and effective properties against caries and bad odours (Yamamoto et al., 1997).

Having a wide range of pharmacological properties, anthocyanins have been used for therapeutic purposes. There is a commercial product (OptiBerry) which consists of standardized levels of anthocyanins as bioactive combination of six selected extracts from wild blueberry, bilberry, cranberry, elderberry, raspberry and strawberry, being a safe food and dietary supplement. This blend has shown excellent antioxidant and antiangiogenetic activities (http://www.optiberry.com.my/product.html). Also, antiangiogenic, antiatherosclerotic and antibacterial properties in particular against Helicobacter pylori have been reported (Zafra-Stone et al., 2007).

Other applications of such bioactive compounds refer to eco-deying technologies based on the fact that many flavonoid compounds are pigments. The lack of harmless and water solubility of anthocyanin pigments makes them good candidates for application as natural water soluble colorants. Nevertheless, their use has been limited as result of their relative low stability and extraction yields. Recent research regarding the use of biomordants and inclusion compounds such as -cyclodextrin to enhance stability of anthocyanin pigments (washing fastness), have extended their application in textile industry as a sustainable eco-technology.

Because most of the natural dyes show positive effect as eco-safe products both for humans and environment, part of our studies dealed with the investigation regarding the application of natural extracts in textile dyeing processes. The cellulosic textiles dyed with anthocyanins extracts can be very useful in developing clothing that protects people against allergies and skin disfunctionalities. The effectiveness of pretreatment with cyclodextrin (β-CD) appears to be an improved dyeing process. Such functionalized materials were characterized using Fourier Transform Infrared (FTIR) and X-ray Diffractometry (XRD), as well as wash and rubbing fastness; using FTIR, the host-interaction have been evidenced by monitoring the changes in some guest molecule band relative to those observed in the spectra. XRD can give the order of structure in the (β-CD) inclusion. The method developed for natural dyeing of cellulose fabrics using anthocyanin extracts in conjunction with cyclodextrin as graft polymerization agent has shown improved parameters in terms of dye adherence and fastness attributes and can thus be recommended for industrial process application.

Due to the current trends facing the replacement of synthetic additives with natural ones including antioxidants in edible oils, and considering the pharmacological potential of anthocyanins, our group intended to study the potential of anthocyanin extracts from various anthocyanin-rich food plants to stabilize polyunsaturated oils in reverse micelle system. The prepared anthocyanin hydroethanolic extracts from bilberry and red onion skins proved efficient potential to oxidatively stabilize unsaturated lipids such as sunflower oil and liver cod oil (Oancea et al., 2013). Anthocyanin extracts of bilberry proved efficient antioxidant potential also for stabilization of cod liver oil formulas, compared to synthetic tocopherols added to the oil. The work reported an inhibition of hydroperoxides generation in cod oil of 20-50.7% when adding bilberry anthocyanin extract, compared to an inhibition of 3-30.4% when using tocopherols, in the first four days of storage. After 11 days, the efficiency of addition of tocopherols seems to decrease drastically. Regarding the shelves storage conditions of cod oil, the authors reported an improvement of oil storage stability by addition of the bilberry anthocyanin extract, as experimented over a 42-day period at 15-17°C. These achievements conducted to a final product with enhanced properties and a great eco-sanogenic potential.

In other reported studies, it was shown that sunflower oil containing small amounts of anthocyanins extracts from blackberry, red raspberry or sweet cherry fruits developed notable resistance to lipid oxidation during storage at 30oC and 60oC compared to untreated samples and samples containing mixed tocopherols (Oancea S., Draghici O., Grosu C., 2016).

The effectiveness of other anthocyanins extracts, such as those from red onion skins was demonstrated on the oxidative stability of sunflower oil, assessed by evaluation of primary and secondary oxidation products, using peroxide value and thiobarbituric acid reactive substances tests TBARS (Oancea S., Grosu C., 2014). The results indicate that sunflower oil containing small amounts of red onion anthocyanin extract exhibits lower levels of lipid oxidation at 40oC during 10 days storage compared to control sample (without any addition) and samples with added tocopherols. A significant decrease of TBARS values of sunflower oil treated with red onion anthocyanin extract was observed compared to the control sample.

All of these results may contribute to future applications of anthocyanins as natural stabilizers of edible oils with nutritionally significant amounts of polyunsaturated fatty acids.

The reported studies regarding the potential application of anthocyanins extracts in meat products showed that anthocyanins may have a protective effect against meat pigments oxidation, good results being obtained whith 0.4% anthocyanins extract (Drăghici O., Oancea S., 2013). This effect depends on the studied animal species, anatomical region of the muscle and the pH of the medium. It was reported that in porcine LT, the myoglobin content was superior to metmyoglobin even after 24 hours, while in case of bovine LL after 24 hours the recorded metmyoglobin content was above 40%. Further research is required to elucidate the role of anthocyanins in lipid oxidation in the presence of porphyrin structures of meat pigments.

In recent years, natural colorants gained great interest for application in textile industry, as safe and eco-friendly alternatives to synthetic dyes. Natural dyes not only contribute to the quality of the traditional textile materials, but also to the sustainable environmental development. Based on the coloring properties of bilberry or red onion anthocyanins, the potential application of such natural extracts in eco-dying technologies of natural cellulosic textile supports was also evaluated and reported (Coman D. et al., 2013; Coman D. et al., 2014). In the reported works, the applied sonication assisted procedure proved to be a suitable method for textile dyeing with anthocyanins based dyestuffs, compared to the conventional dyeing procedure. The enhancement of the dyeing methodology using several anthocyanin extracts was demonstrated in the presence of monochloro-triazine-beta-cyclodextrin, a functional derivate of beta-cyclodextrin successfully used for functionalization of textile substrates.

As overall conclusion, food and non-food products enriched with natural extracts of anthocyanins known for their strong antioxidant capacity are in accordance to the consumer's demand for natural colorants and in accordance to the new environmental considerations in marketing textiles. The use of natural dyes of anthocyanin structure may provide also beneficial effects on human health.

In the future, anthocyanins will still prove their valuable properties in particular through exploiting genetic and biotechnological techniques (cell cultures and tissues) to improve their accumulation in plants, proving efficiency and productivity in many competitive sectors (food, health, industry). Probably this direction will prevail in the coming decades as a result of a drastic decline in traditional plant resources as a result of the concerted action of several factors (disturbances of the ecosystem, unrestricted exploitation, increasing labor costs, problems regarding the cultivation of wild plant species, etc.). The socio-economic impact should not be neglected, the in vitro culture techniques being rapidly adapted to the market requirements.

CHAPTER 4. INSTRUMENTAL PROCEDURES FOR MATERIALS CHARACTERIZATION

Narcisa Vrînceanu, PhD, “Lucian Blaga” University of Sibiu, Romania

Diana Coman, PhD, “Lucian Blaga” University of Sibiu, Romania

4.1. Instrumental techniques for surface characterization

A new instrumental protocol described below was used for the evaluation of the surface architecture and chemical composition of the coloured polymeric matrices. Besides, specific analytical techniques revealed coherent attributes of the green-matrices, in terms of porosity, color strength and fastness.

SR EN ISO 105-X12 standards needing Crockmaster 760 laboratory equipment assisted in performing the dry/wet fastness and colorfastness to rubbing tests. To test the colorfastness to washing, the standard SR EN ISO 105-C10 at 40˚C was adopted (Coman et al., 2014).

4.1.1. Antimicrobial and colouring testing (Coman et al., 2016)

The testing was performed onto two standardized bacterial strains: Staphylococcus aureus ATCC 25923 (Gramm positive) and Pseudomonas aeruginosa ATCC27853 (Gramm negative).

For in vitro testing, Mueller Hinton agar culture medium was used, 24 hours bacterial cultures with a 0,5 Mac Farland Standard microbial density equivalent (1,5 x108 cells), photometrical device for the adjustment of inoculum suspension turbidity, sterile Petri plates. The samples were examined after 24 hours incubation at 37°C.

The tested samples were equally dimensioned, having a surface of 1 cm2. The fabrics made of woolen and knitting samples were embodied in the structure of culture medium, in order to avoid the contact errors with microorganisms from test culture. The samples were placed, so that their centers to be distanced one from the other at least 24 mm. After the incubation at the thermostat under aerobiosis conditions at 37°C, for 24 hours, the samples were evaluated and interpreted in terms of diameter of inhibition area developed around the tested sample area. The determination of inhibition area is performed macroscopically, including the measurement of the diameter of tested sample. To set a limit, we will consider the area on which a relevant increase is not visible.

The absence of inhibition area means the absence of antimicrobial activity.

The results can be compared with the action of gentamicin, in terms of diameter of inhibition area of a micro-tablet having a diameter of 10 mm and a gentamicin concentration of 10 µg. According to the standard CLSI [9,10], the best antimicrobial action is transposed through inhibition area of 19-27 mm belonging to gentamicin onto Staphylococcus aureus strain (ATCC 29213)and of 16-21 mm onto Pseudomonas aeruginosa strain (ATCC 27853).

The experimental dyeing protocol and the colour differences measured by reflexion spectrophotometry can be associated with the green walnut shell quantity, as well as the textile substrate the extracts were applied on. The colour modifications were performed by using the dyeing with natural extract, without mordant, as reference.

The experimental data were acquired with Datacolor 110 LAV reflection spectrophotometer in the CIELab system for parameters, as: ΔL*, Δa*, Δb*, ΔC*, Δh* and colour differences ΔE*.

The characterization systems for the juglone extracts (Coman et al., 2015)

HPLC system consists of: a LC-112 UV Perkin Elmer detector, software for data processing, a system to record the data and a C18 column having the following dimensions: 150 × 4.6 mm, 5µm.

The experimental conditions of juglone determination, by means of its standard/reference, include an acetone percentage in mobile phase (50%), the mobile phase pH was maintained at 4, by using PBS (phosphate buffered solution), and a column temperature of 30°C. In these environmental conditions, the maximum of absorption of juglone does not interfere with other compounds extracted from walnut shells. An elution time of at least 25 min was compulsory in order to remove the undesired compounds presented in the extract.

SERS (Surface Enhanced Raman Spectra) attributed to juglone, were measured, by means of a micro-Raman spectrometer, built-up next to an Olympus, X92 microscope. The experiment set-up is made of He-Ne laser irradiation polarized through some objective lens having a magnitude of 40X. The same objective lens arrayed the reference Raman signal.

The FT-Raman spectra of solid powder were achieved at a resolution of 4.0 cm−1, with a Bruker spectrometer, by using a Nd:YAG laser, (~30 mW), running at 1064 nm.The spectral resolution was estimated at approximately 4 cm–1.

FT-IR IR spectra were acquired with a Bruker Vertex spectrophotometer 60V, at a resolution of 1.0 cm−1. The colorant powder was prepared by employing KBr pellet technique.

The abrasion strength was performed on a NU-Martindale Abrasion Tester according to the standard named SR EN ISO 12947-1_2002 Textiles – Determination of the abrasion resistance of fabrics by the Martindale method – Part 1: Martindale abrasion testing apparatus.

Colour management. The extract colour coordinates were measured using Datacolor 110 LAV spectrophotometer according to CIE system (International Commission on Illumination). The colour values are identified as being the CIELAB coordinates (L*, a*, b*, C*, h) and colour strength (K/S).

The standard illumination was D65, expressed as L*, a* and b* representing lightness (L*) and varies from 0 (black) to 100 (white), redness (+a*), -greenness (-a*), yellowness (+b*), – blueness (-b*), redness (+a*), – greenness (-a*), yellowness (+b*), and blueness (-b*).

From the equation: chroma (C*) and hue angle (ho) values were calculated. Chroma quantifies the intensity of the colorant while in order to show the tonality of the colour, hue angle (h) is expressed on 360o grid.

For dyeing the polymeric supports a (CREST 575D, LG Electronics Tianjin Appliances Co. Ltd, China) ultrasound device was used.

4.1.2. Color strength and fastness testing

Dyeing performance for the samples dyed with colored matter was characterized in terms of colour fastness to washing, wet and dry rubbing also with respect to colour value of CIELAB system with 100 standard observer and illuminant D65. Two different standards were used to assess the washing fastness and color fastness to dry and wet rubbing: EN ISO 105-C10:2007, 40˚C, and SR EN ISO 105- X12:2003, using 760 Crockmaster equipment. The standard grey scale made the set-up of the shifts.

The colour strength of the dyed specimens expressed as K/S is evaluated by a light reflectance technique at maximum. The dyeing colour intensity, meaning K/S values and other chromatic parameters of the dyed bast fabrics were obtained using a Datacolor 110 LAV spectrophotometer and Tools II Plus software from Datacolor Company.

4.2. Morphological/structural modification of different supports

SEM analysis

In terms of morphological structure, the studied specimens were qualitatively analyzed by employing the co-assisted system: scanning electron microscopy and energy-dispersive X-ray spectroscopy. The samples were fixed on copper supports.

The SEM photos were capture using a Quanta 200 3D Dual Beam type microscope, FEI Holland, coupled with an energy-dispersive X-ray spectroscopy (EDX) analysis system, from AMETEK Holland, endowed with an SDD type detector (silicon drift detector), which is an Energy Dispersive X-Ray system for qualitative and quantitative analysis and elemental mapping. The microscope operates at 20 kV with secondary electrons in Low vacuum working mode. Taking into account the sample type, the analyses have been performed, using Low Vacuum working mode, allowing the probes testing in their initial state, without a previous metallization (as in High Vacuum working type). Both for the acquisition of secondary electrons images (SE – secondary electrons) and EDS type elemental chemical analyses, LFD (Large Field Detector) type detector has been used, running at a pressure of 60 Pa in working room, and a voltage of 30 kV.

FT-IR spectroscopy analysis

In order to establish the changes in the molecular structures of the samples, the infrared spectra were acquired using a FT-IR JASCO 660+ spectrometer, running in the 4000-400 cm-1 range. The analysis of studied samples was performed at 2 cm-1 resolution in transmission mode. Typically, 64 scans were signal averaged to reduce spectral noise.

The XPS analysis was implemented using a XPS PHI 5000 VersaProbe (Φ ULVAC-PHI, INC., Thermo Fisher Scientific Co. Ltd).

X-ray diffraction (XRD)

Diffractograms were recorded using a PW1710 diffractometer, using a Cu-Kα radiation (k = 1.54 Å) source (applied voltage – 40 kV, current – 40 mA). The detection of scattered radiation was performed within the range of 10-80° 2θ degrees, at a speed of 1.5° min–1.

BET analysis

The humidity sorption/desorption measurement were assessed by N2 adsorption-desorption isotherms. The assessment of texture attributes, like surface area (SBET (m2/g) and porosity were achieved using an automated sorptometer NOVA 2200e from Quantachrome Instruments, Boynton Beach, FL, USA system, having liquid nitrogen as an absorbate with a temperature of -196 °C. Prior adsorption measurements, according to the BET analysis protocol, the samples were out gassed, for aduration of 6 hours at 25°C, under vacuum, at a pressure lower than 10–3 Torr at 473 K. The determination of specific surface area was conducted using BET method within the relative pressure range of 0.05-0.35; the relative pressure of pore volume was 0.95. By employing the Barett-Joyner-Halenda (BJH) pattern, the distributions of the pore size were quantified from the desorption branches of the N2 adsorption isotherm.

CHAPTER 5. RESULTS AND DISCUSSIONS

Diana Coman, PhD,“Lucian Blaga” University of Sibiu, Romania

Narcisa Vrînceanu, Ph.D, “Lucian Blaga” University of Sibiu, Romania

Ultrasonic coloring – natural dyes

5.1. Colour measurements

The performing of colour management was made using the Datacolor 110 LAV reflection spectrophotometer in the CIELab system with D65 illuminant (standard daylight). Meanwhile the parameters, such as: ΔL*, Δa*, Δb* and colour differences ΔE* were quantified. The references CIE Da – the red-green difference and CIE Db – yellow-blue difference were used to make the interpretation of the achieved results (Tabel 5.1).

By using classic mordant agent, the samples tend to change their colours into green-blue. On the other side, the specimens are placed in the red-orange-yellow zone, especially wool and polyamide samples colored with the two concentrations of biomordant. The bamboo samples occurred in the yellow-greenish area. Exceptions are these samples colored in the presence of citric acid, and situated in red-yellow zone.

Fig. 5.1.a, b, c, d: Significant compared plotting of correlation between textile support(wool, polyamide)-mordant agent concentration- CIE Da*, Db* chromatic attributes (Coman et al., 2016)

The color diagrams are made of collinear points. For the samples colored with the assistance of biomordants, small differences in the red-green and yellow-blue areas are observed.

Table 5.1. Effect of mordants on color data of wool, polyamide and bamboo samples dyed by sonication assisted technique with extracts A and B, derived from green walnut shells and black currant fruits (Coman et al., 2016)

Fig. 5.2:The graphic representations of colour attributes onto the red-green and yellow-blue axis, for the wool, polyamide and bamboo samples simultaneously mordanted and utrasonication dyed with black currant and green walnut shells extract (Coman et al., 2016)

The Figure 5.2 shows the colour changes with almost an exponential increasing, the red green axis being tangent to this augmentation, meaning that even though the supports are different, the colour modification of each support has the same behavior and exponentially increasing with the increasing of the CIE Da*. Another relevant issue is that this increasing stops at 3 point.

A significant appreciation relies on the linearity of some samples, especially those assisted-colored with 3% copper sulphate on Db* (yellow-blue) axis. The other curves show the linearity only on certain parts on Da* (red-green) axis, covering/seeking only wool and polyamide samples.

It is noteworthy to highlight the idea of linear correlation of Da* (red-green) and Db* (yellow-blue) components in case of wool samples colored with extracts A and B, whilst the associated values of these chromatic parameters to polyamide and bamboo samples are not linear. This outcome undoubtedly demonstrates that only wool samples would have stable chromatic components (Da* and Db*), compared with the other studied samples.

Fig. 5.3: The graphic representations of colour difference – mordant concentration for: wool polyamide bamboo samples dyed with extracts A and B; (polyamide sample1 and polyamide sample2) supports dyed with green walnut shells and black currant extracts,; extracts A and B (water:ethanol 1:1 and water:ethanol 3:1) (Coman et al., 2016)

The lightness of all samples dyed by sonication assisted procedure increases up to 3%, more or less, as value of biomordant concentration.

It is noteworthy to mention that at 5% concentration of biomordant, no matter which one we choose, the lightness diminishes, and the lowest values for all samples are on the same line.

A pertinent observation is attributed to bamboo samples that have a total different graphical attitude – which could not be represented. An explanation could be derived from the intense action of ultrasonic waves amplifying the cavitation and implicitly the interaction between active substances from mordant agents with the dye and textile supports.

The great differences of colour, meaning the dyeing intensity with different concentrations of mordant agents and do not appear plotted in the graphic above, are relevant for polyamide colored with extract A, obtained from black currant fruits, while for polyamide dyed with extract B, the colour differences are relatively lower.

5.2. Fastness measurements

Table 5.2 illustrates all colorfastness properties of mordanted colored fabrics with green walnut shells and black currant fruits extracts. From these results, it is obviously that colorfastness to washing and rubbing are fair to very good.

Table 5.2 also reveals that the treatment with tannic and citric acid and CuSO4, improves colorfastness to washing of bamboo while the mordant agents do not affect the colorfastness to rubbing.

Table 5.2. Effect of mordant agents on washing and rubbing fastness properties of wool, polyamide and bamboo textile supports dyed with natural extracts (Coman et al., 2016)

The plotting of these data belonging to the fastness values are illustrated in Fig. 5.3, Fig. 5.4 and Fig. 5.5. Up to 3% concentration of mordant agent, the washing fastness of both samples has the same behavior. After the 5% value of concentration of mordant agent, this parameter tends to decrease, in case of polyamide sample, while the bamboo sample has the same allure of the graphic. The explanation could rely on the behavior of the natural polymer with respect to sonication dynamics.

Fig.5.3:The graphic representation of washing fastness of polyamide and bamboo samples (Coman et al., 2016)

Fig.5.4: The graphic representations of wet rubbing fastness belonging to wool, polyamide and bamboo samples (Coman et al., 2016)

Comparing colorfastness properties, it is clear that fastness to washing is fair to good in case of polyamide and bamboo samples, at high concentration of mordant agents. Also, colorfastness to dry rubbing is fair to very good in case of bamboo samples, keeping a constant tendency, no matter the mordant concentration was employed. It is clear that treatment of textile supports using classic and biomordant agents in the same time with the sonication assisted dyeing, enhances colorfastness to washing, with exception of CuSO4 /wool, citric acid /wool, tannic acid /polyamide and citric acid /bamboo at low treatment concentration.

The results indicate that simultaneously mordanting of wool, polyamide and bamboo fibrous supports with 3% mordant agents shows poorer fastness properties as compared to those colored with 5% as shown in Table 5.2. The measurement of chromaticity values within CIEL*a*b* system are higher for the biomordanted fabrics as compared to metal mordanted samples.

Fig.5.5: The graphic representations of dry rubbing fastness belonging to woolen and polyamide samples (Coman et al., 2016)

Both sonication assisted procedure and mordant assisted dyeing have a complex effect sustaining the final result of this modern coloring methodology of textile materials.

Fig.5.6: The graphic representations of colour difference values versus fastness properties units for: wool, polyamide and bamboo samples (Coman et al., 2016)

By using ultrasonic dyeing methodology, the fibrous supports are stable in terms of washing and dry rubbing fastness, in case of polyamide and woolen specimens.

5.3. Coloristic and antimicrobial behaviour of polymeric substrates using bioactive substances

b. polymeric substrates colored with bioactive substances

Table 5.3 reveals the colour coordinates, meaning luminosity and colour differences for the polyamide (PA1 and PA2) samples colored with extracts A and B, woollen and bamboo samples. The values of luminosity and colour differences are changing in terms of the mordant type used in dyeing process (copper sulphate, citric and tannic acids).

Table 5.3. The values of luminosity and colour differences for the wool, polyamide and bamboo samples dyed with extracts A and B, made of green walnut shells and black currant fruits (Coman et al., 2016)

The highest colour changes are noticeable for bamboo samples treated with copper sulphate, whilst the lowest are occurred wherein the dyeing was assisted by CA and TA.

By comparison the three textile supports colored with black currant and nut shells extracts, visualizing Fig. 5.7, it can assumed that major colour changes are remarkable when the dyeing is assisted by citric acid (CA) as biomordant, the classic one leading to irrelevant colour differences.

Generally speaking, the lightness of bamboo samples reveals a decrease when 3 and 5% concentrations of CA are used, but a major augmentation, between them is noticed, when TA and copper sulphate are assisted the dyeing. The plots recorded collinear points situated on the same line, in the colour diagram. Small differences in the red-green and yellow-blue areas are noticed, for the samples with biomordants. It is noteworthy to highlight the idea of linear correlation of Da (red-green) and Db (yellow-blue) components in case of woolen samples colored with extracts A and B, whilst the associated values of these chromatic parameters to polyamide and bamboo samples are not linear. This result reveals the fact that only woolen samples would have stable chromatic components (Da and Db), the other studied samples being with no consistency in this regard.

Fig 5.8 representing the colour difference versus mordant concentration for the woolen, polyamide and bamboo samples colored with different natural extracts shows a coherent relation (CIE DE values for all samples are situated on the same line, in case of mordant concentration of 3 and 5 g/L, respectively) between colour differences for all samples, no matter the polymeric fibrous supports are.

For the woolen and polyamide samples, colored with walnut shells, the samples are brighter when the dyeing is assisted by the TA, and their modification quantified in colour difference has considerable values only by assistance of 5 % concentration of copper sulphate and TA, the other ones being in the acceptable ranges.

Fig.5.9:The correlation between colour difference and antimicrobial activity of woollen, polyamide and bamboo samples with green walnut shells extract B (b) and A (a) tested against Pseudomonas aeruginosa ATCC 27853 (Coman et al., 2016)

Regarding the antimicrobial performance, it can be stated that the more concentrated extract was used, the higher the antimicrobial activity and colour differences. The figure above reveals an increase of inhibition diameter for polyamide samples colored with the two extracts against CIE DE value (3 arbitrary units). It is also noteworthy to underline the increasing of growth diameter with CIE DE value, an approximately linear correlation.

The obtained results showed a favourable distributed antimicrobial action against Gramm negative bacteria. The strain of Pseudomonas aeruginosa expressed a moderate sensitivity in terms of woollen samples colored with B extract (high concentration of green walnut shell extract) (Fig.5.10) fixed with 3% CA (diameter of inhibition area is 14 mm), 5% AC acid citric (diameter of inhibition area is 16 mm), 3% TA (diameter of inhibition area is 13 mm), 5% TA (diameter of inhibition area is 15 mm), in comparison with Gentamicin, wherein the diameter of inhibition was 16-21 mm.

Fig.5.10:Woollen samples with green walnut shells extract B (b) and A (a) tested against Pseudomonas aeruginosa ATCC 27853 (Coman et al., 2016)

These samples were colored with the highest concentration of green walnut shell extract (more intense colored samples – right side of the Fig. 5.10), with the assistance of CA and TA as biomordants.

The woollen dyeing with A extract (a small concentration of green walnut shell extract), by using the same mordants and tested against Pseudomonas aeruginosa, has not induced antimicrobial attributes to the tested samples. Nevertheless, this dyeing manner had a moderate antimicrobial activity against the strain of Staphylococcus aureus, by using of mordants. For instance, in case of 3% copper sulphate (the diameter of inhibition area is 12 mm), for 5% copper sulphate, the diameter of inhibition area is 13 mm). With the assistance of 5 % TA, the diameter of inhibition area was 13 mm, in comparison with Gentamicin, where the diameter of inhibition area was 19-27 mm

.

Fig. 5.11: Woollen samples dyed with green walnut shell extract (A), tested onto Staphylococcus aureus, according ATCC 29213 (Coman et al., 2016)

The antimicrobial activity of woollen samples colored with A extract, was relevant only for samples wherein TA and sulphate copper were used against Gramm positive bacterial strains (Staphylococcus aureus). B extract expressed a better antimicrobial activity at samples wherein CA and TA were used as mordant against Gramm negative bacterial strain (Pseudomonas aeruginosa).

This differentiated action has the cellular wall structure at Gramm positive and negative bacteria, as basis, which in terms of the action and the type of chemical aggressive agent expresses sensitivity or resistance. Gramm positive bacteria presents a thick cellular wall (15-50 nm), relatively homogenous made of many layers of peptydo-glycans, and at Gramm negative bacteria the cellular wall is thinner (3-8 nm), but has a more complex structure (Guguianu, 2002).

Fig. 5.12: Antimicrobial performance of polyamide supports dyed with green walnut shells B extract(Coman et al., 2016)

The dyeing with extract B (a high concentration of green walnut shell natural dye) onto polyamide support, with the assistance of 5% tannic acid (TA), as mordant, had a very good antimicrobial performance, the inhibition area diameter being 22 mm (Fig. 5.12).

Fig.5.13: Photos on PA supports dyed with extract B (a high concentration ofgreen walnut shell natural dye) , with the assistance of 5% CuSO4, 5% CA and 5% TA, tested against Pseudomonasaeruginosa ATCC 27853 (Coman et al., 2016)

Fig. 5.14: Correlation between biomordant concentrations and inhibition area diameters, of the studied samples, against Pseudomonas aeruginosa ATCC 27853(Coman et al., 2016)

Figure 5.14 reveals a perfect linear correlation between biomordant concentrations and inhibition growth diameters, in case of colored woollen polymeric support with the assistance of 5 % concentration CA and TA, against Pseudomonas Aeruginosa ATCC 27853.

Figure 5.15 depicts the effect of refluxing time over the juglone water extraction. After two hours of refluxing irrelevant differences could be noticed, which is why a two-hour span is the most appropriate for the extraction.

Fig. 5.15: The effect of reflux duration onto the percentage of juglone extracted from green walnut shells (Coman et al., 2016)

Figure 5.16 presents the chromatograms assigned both to the juglone solution extracted from green walnut shells and standard juglone. In experimental conditions, the retention time for juglone is approximately 6.3 min, and its identification in the solution was made by comparison with the retention duration of standard juglone. The HPLC technique quantitatively highlights the efficiency of the ecologic procedure of juglone extraction. It can certainly be claimed that the percentage of the extracted juglone is relatively high (2.79% juglone in 0.1 g walnut shells), conducting to the remark that the 100 % juglone was extracted from a weight of 3.58 g of walnut. Technically, the yield is higher than 50%.

Fig. 5.16: The chromatogram belonging to aqueous extract of the juglone standard powder (A); the chromatogram belonging to aqueous extract of the juglone powder from green walnut shells (B) (Coman et al., 2016)

Comments on juglone spectra

Discrete Fourier Transform calculus was performed in order to obtain IR and FT-Raman spectra of juglone powder. The solid sample of juglone has a high reflectance and thus the FT-Raman spectrum is “noisy”, and the bands intensity is decreased (Bowie et al., 1965; Lee et al., 2006; Whitney et al., 2006; Pawar et al., 2011).

Fig.5.17: FT- IR, FT-Raman and SERS spectra belonging to double bond of juglone (Coman et al., 2016)

However is noteworthy to mention that FT-IR and FT-Raman spectra are very different, with respect to bands intensity. Nevertheless, in most cases, similitude in terms of the bands frequency occurs when compare two of the spectra. The strongest bands from the region specific to double bond (1700-1400 cm−1) lead to the assumption of double bond shift, in case of the natural colorant. The strong bands are noticed, not only at double bond, but also within IR region (300 cm–1 – 1000 cm–1) belonging to SERS spectrum. Technically, the regions specific to juglone double bonds, belonging to IR, FT-Raman and SERS spectra are shown in Fig. 5.17(Pavia et al., 2000).

The interpretation of data provided by colour measurement protocol

Table 5.4 reveals the colour coordinates, meaning luminosity andcolour differences for the woolen samples colored with extracts A and B. The values of luminosity and colour differences are changing in terms of the mordant type used in dyeing process (copper sulphate, citric and tannic acids).

The highest colour difference is attributed to the woolen samples colored with extract A, in the presence of copper sulphate, as mordant. The lowest differences are noticed at samples colored with the assistance of tannic and citric acid (concentration of 3%) as biomordants, with reasonable color changes with respect to the reference.

Table 5.4. The values of luminosity and color differences attributed to the woolen samples dyed with extract A (water: ethanol 1:1) and B (water: ethanol 3:1) consisting of green walnut shells (Coman et al., 2016)

The luminosity colored with extract A is diminished, the most luminous being the ones dyed with the assistance of tannic acid (concentrations of 3 and 5%). The luminosity of woolen sample is higher in case of extract B, the most luminous being the ones colored with the assistance of 3% copper sulphate and 5% acid citric, and the lowest being the specimen colored using 5% copper sulphate, assuming that the mordant concentration influences in a major manner the brightness of the samples.

Table 5.5. The values of luminosity and colour differences for the polyamide (PA1 and PA2) samples dyed with extract A (water:ethanol 1:1) and B (water:ethanol 3:1), made of green walnut shells(Coman et al., 2016)

Table 5.5 also reveals the colour coordinates, meaning luminosity and colour differences for the polyamide (PA1 and PA2) samples colored with extracts A and B. The values of luminosity and colour differences are changing in terms of the mordant type used in coloring process (copper sulphate, citric and tannic acids).

A high colour difference is noticeable at samples colored with extract A and B, with the assistance of both mordants: copper sulphate and tannic acid. The lowest differences are shown at samples assigned to experiment paths using acid citric as biomordant (concentrations of 3% and 5%), consequently the colour changes compared to the reference are detectable. Generally speaking, the luminosity of polyamide (PA1 and PA2) samples is decreased, the most luminous being the ones dyed with the assistance of tannic acid (concentrations of 3% and 5%), for both extracts A and B.

Fig.5.17: The graphic representations of colour attributes onto the red-green and yellow-blue axis, for the woolen and polyamide (PA1, PA2) samples dyed with extract A (water:ethanol 1:1) and B (water:ethanol 3:1) (Coman et al., 2016)

The woolen samples colored with extract A have red-yellow tint and slightly greenish as well, and those dyed with extract B, are partially red-yellowish tinted and partially greenish-bluish. The polyamide (PA1 and PA2) samples colored with extract A are red-yellow tinted, while the ones colored with extract B, are different tinted: some of them are red-yellowish tinted, and some of them are both greenish-yellowish and even blue-greenish. The presence of colour intensity, meaning the dye deposition is noticeable where the colour modifications are detectable. In case of colour difference is not consistent; the biomordant occurrence would be successfully used in the dyeing technology.

The values of colour difference for polyamide (PA1 and PA2) samples dyed with both extracts (A and B), are well depicted, stressing the linear correlation assigned to the same mordant concentration 3% or 5%, the colour modification progressively diminishing from the samples colored by assistance of copper sulphate (3%, 5%), towards the 5% concentration of tannic acid. The small values of colour difference assigned to woollen samples can be associated to the small concentrations of mordant, for both extract A and B. Thus, undoubtedly a 3% concentration of citric acid attributed to extract B, conducted to an acceptable modification of colour.

5.5. Behaviour of eco-dyed textile composites

SEM results are presented in Figs. 5.18 and 5.19, which compare the microscopic surfaces of reference samples, both L and L-MCT-ß-CD, on one side and the grafted and colored samples: samples 1 and 4, on the other side.

From the visual analysis of SEM images, the following can be noticed: uniform appearance with small irregularities in case of sample 4, revealing the cumulative/coherent result of both functionalization with MCT-ß-CD and ultrasonic dyeing; quality, with varying degrees of roughness, with smaller or larger bumps, in case of the reference samples.

The well-dispersed bright lines belong to the treated samples. Functional groups can form hydrogen bonds, leading to the strong interaction between anthocyaninmolecules and MCT-β-cyclodextrin. The results indicate that the anthocyaninmolecules were blocked in the cyclodextrin cavity

Fig. 5.18: SEM images at X5000 magnification – L; L – MCT- β-CD (Coman et al., 2014)

Sample 2 Sample 4

Fig. 5.19: SEM images at X5000 magnification for sample 2; sample 4 (Coman et al., 2013)

In the case of the physical mixture and inclusion complex, spectra seem to acquire the peak specific to MCT-β-CD and the natural dye, being more sharp, which leads us to the conclusion that these changes are due to the anthocyanin molecule inclusion in MCT. Furthermore, there occurred a few modifications in IR observable at 1628-929 cm-1.

The disposal of pore size was established from the nitrogen adsorption isotherm, by employing the Barett-Joyner-Halenda model (BJH model). Isotherms and distributions corresponding to the pore sizes have been plotted (Fig. 5.20).

Fig. 5.20: The N2 adsorption/desorption isotherms of the inclusion compound (MCT-β-cyclodextrin-as host and natural dye as guest molecule) (Coman et al., 2013)

An IUPAC IV type isotherm was revealed by the general aspect of the sample isotherms, characteristic of the porous absorbers, showing the so-called capillary condensation phenomenon 4 (Coman et al., 2013)

In Fig. 5.21, the pore distribution calculus indicates some mesopores, whose radius is 4.7968 nm for MCT-β-cyclodextrin and 4.3 nm radius for dye pore, respectively. In the area of partial pressure values higher than p/p0 >0.5, the isotherm discloses the debut of an H3 type hysteresis, illustrating pores with a relatively even distribution.

.

Fig. 5.21: The pore size distribution (PSD) of the dye/CD composite4 (Coman et al., 2013)

Figure 5.22 unveils the IR maximum of the solid natural dye, M-β-CD, the physical mixture and inclusion compound. The M-β-CD exhibited significant FTIR peak at a wave number of 955, 1093, 1241, 1443, 2321 cm-1, while the natural dye showed FTIR peaks at a wave number of 899, 1176, 1530, 2176, 3019 and 3320 cm-1. Moreover, strong peaks at 3500 (hydroxyl group) and at 1710 cm-1 (carbonyl group) are noticeable.

Fig. 5.22: FT-IR spectra for linen supports dyed with blackberry natural extract4 (Coman et al., 2013)

Table 5.6. The colorfastness of linen fabrics dyed with blackberry extract

The color fastness values for samples dyed with blackberry (Rubus spp.) anthocyanin extracts reveal the rub and wash fastness of most of the samples to be moderate to good, especially for samples previously functionalized and colored, bringing us to the new approach to this method.

The quantifying of abrasion stability was performed, taking into account the results provided by the literature, sustaining the weight loss values for each fabric sample increasing gradually with the increase in the abrasion cycles (Coman et al., 2013)

In our experiment, the main values of color difference are observed between 0-3000 cycles of abrasion. After 3000 cycles, color strength was evaluated by measuring reflectance intensity and calculating the K/S at wavelengths between 400 and 700nm under D65/100 illuminant, using Datacolour SP2000 Check II portable spectrophotometer from Datacolour company.

Table 5.7. Colour results of linen fabrics after abrasion test

The dyed samples were tested for fastness, by comparing reference samples with the targeted studied specimens. At the end of the 3000 cycles, the lowest/non- relevant significant weight loss values were noticed for samples US colored (0.02 g). Along with small color values measured after abrasion test, this fact testifies that the deposition of natural dye is more stable and efficient in the case of grafted and ultrasounds dyed samples.

This statement is very well sustained by the BET analysis, exposing the blocking of colorant molecule in the MCT-β-cyclodextrin cavity. Thus, there is a noticeable change in color intensity, experienced by the friction test of warp and weft yarns, for non-functionalized and dyed by exhausting procedure samples.

On the contrary, due to the entangling of dye molecule inside of MCT-β-cyclodextrin’s nanocavity, the K/S value shows abrasion strength. It can be claimed that US dyeing made with natural coloring matter is more resistant, with a minimum discoloring of samples, especially previously functionalized samples. The color differences values between control and abraded samples slightly increased as the number of abrasion cycles increased.

For non-functionalized, dyed and then abraded samples, the measured color differences shifts with approximately 2-2.5 points. For functionalized samples, the difference does not overpass 1.5 point, proving once more the protection of natural dye entrapped into cyclodextrin nanocavity.

Loss of mass is higher in the non-functionalized and colored samples through dye-fiber interaction than those functionalized and dyed by the sonication assisted procedure.

Fig. 5.23 presents the dependence of the attained color values (K/S) on the ratio between the MCT-β-cyclodextrin radius and the dye radius. It can be noticed that increasing the above mentioned ratio gave relatively higher K/S values for colored pretreated bast fabrics. In other terms, the higher the ratio between the MCT-β-cyclodextrin radius and the dye radius, the smaller the color values between control and abraded samples.

Fig. 5.23: Dependence of the color value of the samples on the

MCT-β-cyclodextrin radius/Dye radius ratio

SEM images from Fig. 5.24 belong to flax support, non-functionalized (non-grafted), under different magnifications. The differences between reference sample and the samples coloured with the assistance of the two promoters CA, as mordant, and MCT-β-CD as cavity for inclusion complex are notable.

Fig. 5.24: SEM/EDX images at X 1090 magnification for: F- reference flax support; F-MCT-β-CD grafted (functionalized) flax support.

The morphology of surface in case of the grafted sample dyed with natural extract is more consistent than that belonging to sample colored in the presence of CA.

In addition, according to the SEM images from Fig. 5.25, the uniformity of the MCT-β-CD grafted sample and dyed with natural extract, is better than that of sample colored with the assistance of citric acid.

Here the SEM results showed that the convolution of the vegetable fiber surface was smooth and there was no distinguishable physical modification of the surface.

Fig. 5.25: SEM images at X 2500 magnification for: 3- flax fabric dyed with 1% black cherry extractby exhaustion, without mordant; 4- flax fabric dyed with 1% black cherry extractby exhaustion, with mordant.

The evidence that a specific inclusion complex was reached was certified by matching the FT-IR spectra belonging to vegetable polymeric substrate with those grafted with MCT-β-CD and for the sample naturally coloured with mordant.

As shown in the FTIR spectra (Fig.5.26), there are some specific absorption bands: for MCT-β-CD, the absorption bands between 1000 and 1200 cm-1 are ascribed to the –C–O– stretching on polysaccharide skeleton. The peaks at 1420 and 1610 cm-1 correspond to the symmetrical and asymmetrical stretching vibrations of the carboxylate groups (Rosca et al., 2005).

The peak at 2920 cm-1 was ascribed to C–H stretching associated with the ring methane hydrogen atoms. Due to the wide distribution of hydrogen-bonded hydroxyl groups, a broad band centered at 3450 cm-1 was noticed.

Fig. 5.26: FT-IR spectra for flax fibers supports (functionalized and non-functionalized) dyed with black cherry extract dye

In Fig. 5.27, the spectrum ascribed to sample colored with the assistance of citric acid solution has a stretching band at 1,625 cm−1 attributed to the C=O in the dissociated carboxylic acid, while it is 1,730 cm−1 when not dissociated (Socrates, 2001).

Fig. 5.27: FT-IR spectra for flax fibers supports dyed with black cherry extract, without the assistance of mordant /in the presence of the mordant

Fig. 5.28: The N2 adsorption/desorption isotherms of the complex compound obtained by inclusion black cherry extract in MCT-β-cyclodextrin-as host molecule

To elucidate this behavior we refer to the isotherms presented in Fig.5.28. The isotherm alure of the inclusion compound reveals a small contributions of micropores for N2 adsorption, demonstrating the fact that dye molecules are located inside of the inclusion complex micropores, knowing that the attraction between the hydrophobic parts of CD and dye molecules is due to the sorption mechanism combining the presence of CD but also from physic-chemical interactions in the micropores.

Fig. 5.28 revealed an IUPAC IV type isotherm specific to the porous adsorbers, showing the capillary condensation phenomenon (IUPAC, 1985).

The inset presents the pore distribution calculus indicating some mesopores, whose radius is 6.22 nm for MCT-β-cyclodextrin and 5.88 nm radius for dye pore, respectively. In the domain of partial pressure values higher than p/p0 >0.5, the isotherm detects an H3 type hysteresis, hinting evenly distributed pores.

By employing citric acid as mordant agent assisting the dyeing of flax fabric with black cherry extract provided good and moderate fastness coordinates/properties as given in Table 5.8. To obtain stable shades with acceptable colorfastness behavior the inclusion method is compulsory. Abrasion resistance testing was performed for determining the color resistance of samples before and after coloring treatment.

Table 5.8.The fastness values of flax composites dyed with black cherry extract

FT-IR spectra of the targeted samples are presented in Figure 5.29, and supported the essence of this study that the inclusion complex process steadily devoted to the surface architecture of the samples, these data being well correlated with colour measurements information, meaning K/S values.

Hence FT-IR spectra display some absorption bands assigned to this type of supports.

Fig. 5.29:FT-IR spectra of: (A) –Linen support functionalized with MCT-β-CD dyed by sonication procedure with 2% wild black cherry extract; (B) – Linen support functionalized with MCT-β-CD dyed by exhaustion procedure with 2% wild black cherry extract; (C) – Linen support grafted with MCT-ß-CD; (D) – Reference linen support grafted

BET results interpretation. The examination of porosity was performed by N2 adsorption/desorption techniques. According to the Figure 5.30, all samples are associated to the IVth class, with a plateau at relative high pressures, characteristic to inclusion compounds. The cavities’ dimensions are given in Table 5.9 below and unveil that porosity is influenced by the coloring method.

Fig. 5.30: N2 adsorption/desorption isotherms for the most signifcant studied samples

Table 5.9. Pores information for nanocavities belonging to the most signifcant studied samples

The above isotherms (Fig. 5.30) exhibited the uptake of N2 at medium relative pressures, this response being typical for inclusion compounds. All isotherms are IV type associated to inclusion compounds, and hysteresis loop belongs to H1 type, indicating the occurrence of pores/cavities.

Fig. 5.31: Adsorption isotherms of tested samples with N2 at 77.35 K (A) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – low ultrasonic volume; (B) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – high ultrasonic volume; (C) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – medium ultrasonic volume

The hysteresis loop in the isotherm is formed due to the capillary condensation of N2 gas occurring in the mesopores, consequently, the IVtype of isotherm is considered the characteristic feature of the inclusion compounds materials (Gilles et al., 1960). The sharp rise near p/po = 0.4 corresponds to condensation in the primary pores.Plotting the amount of dye extract adsorbed at equilibrium (qe) against final concentration in the aqueous phase (Ce) at different ultrasonic volumes, and different type of supports gave a characteristic H-shaped curve as shown in figures below.

Figure 5.32 reveals S shape of sorption isotherms, assuming different affinities of MCT-β-CD cavity for dye molecule entrapped in different paths of coloring, statement supported by the decreased values of sorption capacities, such as: 38 mg/g for 3 indexed sample and 13 mg/g for 1 indexed sample, the maximal concentration at equilibrium being 60 mg/L.

Fig. 5.32: Sorption isotherms of wild black cherry extract onto linen supports, on different supports: 1- Functionalized linen support with MCT-β-CD dyed by exhaustion procedure, with 2% black currant extract; 2- Functionalized linen support with MCT-β-CD dyed by sonication procedure (low ultrasonic volume, with 2% wild black cherry extract; 3- Functionalized linen support with MCT-β-CD dyed by sonication procedure (medium ultrasonic volume, with 2% wild black cherry extract; 4- Functionalized linen support with MCT-β-CD dyed by sonication procedure (high ultrasonic volume, with 2% wild black cherry extract

In Figure 5.33, the shape of N2 adsorption/desorption isotherm attributed to sample A – inclusion compound dye extract – MCT-ß-CD, is slightly different from the shape of isotherms previously approached, depicting some specific aspects within two porosity domains. This sample presents a II type isotherm, with hysteresis loop belonging to H3 type, assuming the presence of inclusion compounds. In this case the hysteresis loop closes to lower values of relative pressures, p/p0 ~ 0.4. This response sustains the idea of occurrence of more types of cavities with dimensions in the range of mesopores, fact confirmed by the pores dimensions distribution (the inset Figure 5.33c). In the area of relative low pressures, p/p0< 0,2 the micro porosity is noticed.

In case of B sample (bast support grafted with MCT-ß-CD and coloured with natural extract by sonication procedure – low ultrasonic volume) the shape of N2 adsorption/desorption isotherm is completely different. The isotherm modifies its allure, changing into IV Type, according to IUPAC classification, with a hysteresis loop of H1 type (firstly known as A Type), showing a plateau at relative high pressures, with adsorption/desorption branches approximately parallel. This type of isotherm is now called by Rouquerol (Rouquerol et al., 1991), as being of IV Type and the presence of porosity derived from the aggregation of nanocavities.

Fig. 5.33: N2 adsorption/desorption isotherms at -196°C and the pores dimension distribution (insets) belonging to: (A) inclusion compound dye extract- MCT-ß-CD (B) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – low ultrasonic volume; (C) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – high ultrasonic volume; (D) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – medium ultrasonic volume

According to the slope of the initial portion of the curve of natural dye extract onto CD nanocavity, this isotherm may be classified as H-shape according to Giles classification (Gilles et al., 1960).In this type of isotherm, the initial portion provides information about the availability of the active sites to the adsorbate and the plateau signifies the inclusion compound formation. The initial curvature indicates that a large amount of dye is adsorbed at a lower concentration as more active nanocavities are available. The cavities dimensions distributions, as well as pororosity data are presented in Table 5.10, showing that the micro cavities represent approximately 20% from the total specific surface recorded for this sample.

Table 5.10. Porosity data for nanocavities assigned to: (A) inclusion compound dye extract- MCT-ß-CD (B) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – low ultrasonic volume; (C) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – high ultrasonic volume; (D) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – medium ultrasonic volume.

The presence of microporosity, in this case, is more obviously in the relative low pressures p/p0< 0,2, fact confirmed by the plot distribution of pores dimensions, according to the radium pores, revealing the occurrence of porosity. In this case, microcavities contribute with approximately 25% from total specific surface (266 m2/g) measured for this specimen.

All these considerations show that the type of inclusion compounds formation and the aggregation/agglomeration are responsible with the porosity noticed in each case.

As the Table 5.11 shows, K/S values augment as specific surface area data increase, suggesting that the colour intensity becomes darker for specimens coloured with natural extract by ultrasounds powered procedure – medium ultrasonic volume, the values being 6.97 and 7.20.

The highest C* values in Table 5.11 indicates that the linen fabrics are dyed with the highest saturation and the colors obtained are intensively saturated and in a direct relationship with dye uptake. The lightness (L*) value conducts to idea of darkness for samples colored by sonication, and fastness values highlight the fact that by entrapment of natural dye within the MCT cavity, the colour loss is preserved, after washing and rubbing, the values ranging in 3-5 grades. This performance is also the result of cavitation dynamic in coloring bath.

Tabel 5.11.Colour fastness properties of the fabric dyed by using ultrasonic and standardmethod

As the Fig. 5.34 shows, K/S values augment as specific surface area data increase, suggesting that the colour intensity becomes darker for specimens colored with natural extract by ultrasound powered procedure – medium ultrasonic volume, the values being 6.97 and 7.20. This means the higher the SBET the more quantity of dye entrapped in the cavities/pores, which in terms of colour measurement is translated by more intense coloured samples.

Fig. 5.34:Plot representing intensity colour in terms of specific surface area data of nanocavities belonging to (A) inclusion compound dye extract-MCT-ß-CD (B) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – low ultrasonic volume; (C) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – high ultrasonic volume; (D) – linen support grafted with MCT-ß-CD and dyed with natural extract by sonication procedure – medium ultrasonic volume

f. Comparison between ultrasounds powered and conventional dyeing of flax

fibres with Allium cepa anthocyanin extract

SEM investigation

Scanning electron microscopy (SEM) permitted to visualize separate vegetable fibers in much more detail. Figure 5.35 reveals the difference between the untreated fiber (F) and the fiber grafted with MCT-β-CD (F-MCT-β-CD), at magnifications of X5000 and X12000. Using the SEM analysis, little bolls were observed on the surface, which were not observed in the reference material. Grafted samples were considerably stiffer than untreated samples. A significant change of surface morphology was observed.

As shown in Figure 5.36, sample 2 has the typical convolutions of flax, and still possesses the main morphological characteristics of vegetable fibres, but the natural dye is distributed non-uniformly. An evenly distributed MCT-β-CD film is visible on the fiber surface of sample 3. At larger magnifications, i.e. X12000, the differences between the colored untreated and colored grafted support become even more obvious and the change in the morphology of the fiber surface can be clearly observed, as shown in Figure 5.37.

As observed in Figure 5.37, a more uniform distribution of the natural dye on the fibre surface is obtained in sample 7 (non-functionalized support dyed with 2% natural extract), compared to sample 5 (non-functionalized support colored with 1% natural extract), which has a rough distribution.

Figure 5.38 presents comparatively the grafted samples dyed with two different concentrations of the anthocyanin extract. It clearly reveals that the higher the dye concentration, the more uniform the coating achieved. The explanation relies in the fact that the higher the concentration of the grafting agent, the higher the possibility of chromophores or groups to covalently bind/attach to the active groups belonging to grafted fiber, conducting to a proportional distribution of the dye molecules.

Binding strength depends on how well the host and guest fit together in the complex and on specific local interactions between surface atoms.

With respect to the samples colored by ultrasonication, the uniform distribution is much more notable than in the previously grafted sample and dyed by the same procedure, as presented in Figures 5.37 and 5.38. In the case of the grafted vegetable fibre, the dye did not cover the entire surface of the sample. On the contrary, some small balls can be observed.

The images reveal that the natural anthocyanin extract is more uniformly deposited on the fibre surface, in the case of the previously grafted sample, as compared to the specimen colored with the same extract, but in the absence of MCT-β-CD, where the dye has been scarcely diffused on the fibre. This result is very well supported by the color measurements: the grafted samples present a good dye distribution, with pale, but wash resistant colours.

Fig.5.35: SEM images at X5000 magnification for samples F and F-MCT-β-CD (Coman et al., 2014)

Fig.5.36: SEM images at X12000 magnification for samples 2 and 3

(Coman et al., 2014)

Fig.5.37: SEM images at X12000 magnification for samples 5 and 7 (Coman et al., 2014)

Fig. 5.38: SEM images at X12000 magnification for samples 6 and 8

(Coman et al., 2014)

The control samples have vivid colours, but are not resistant in terms of washing and rubbing fastness. The changes are homogeneous, as the free radical graft polymerization is initiated over the entire fiber simultaneously.

To investigate the morphological changes caused by the chemical modifications, SEM observation was performed. Figure 5.39 shows SEM images of untreated cotton fiber and D-9-mer Peptide-Immobilized Fibers. These images demonstrate that the convolution and the spiral secondary wall which were characterized as cotton fiber were maintained after the chemical modifications.

Fig. 5.39: Scanning electron micrograph for untreated fiber (a, b) and D-9- mer peptide-immobilized fibers (c, d) (Coman et al., 2015; Nakamura et al., 2011)

In case of bast samples grafted with mono-chloro-triazinyl-cyclodextrin, SEM morphology provided information concerning adsorption mechanisms of black currant extract onto bast fibres. From Figure 5.40 it was clear that the interfibre capillaries were responsible for retaining a significant amount of pigment. Subsequently, uptake by the interfibre capillaries was the main adsorption mechanism rather than adsorption on the fibre surface. Bast fibre was observed to have several key properties such as hydrophobicity, good affinity for black currant extract, rapid adsorption on contact, and high adsorption and retention through interfibre capillaries.

Fig. 5.40: SEM images at X5000 magnification – L; L -β-CD (Coman et al., 2013)

EDX – elemental analysis

EDX analysis revealed a proportionally decreased content of nitrogen and chlorine – as the main chemical elements coming from the triazinyl group – with the modification of coloring conditions. In the case of samples 1 and 4, nitrogen showed the highest content. The decrease of the nitrogen content can be explained by the fact that the triazinyl group is involved quantitatively in the reaction with the dye molecule, which is supported by the FT-IR spectroscopy.

Fig.5.41: FT-IR spectra for flax fiber supports dyed with Allium cepa anthocyanin extract (Coman et al., 2014)

XRD pattern interpretation

The XRD patterns presented in Figure 5.42 exhibit two main specific peaks for vegetable fibres, as follows: four well-defined peaks at 22.0° and34.4°, corresponding to the 002 and 004 planes, which is in accordance with the literature (Revolet al., 1987); Tserkiet al., 2005). In the case of the functionalized lignocellulosic support, two peaks appeared around 22.0° and 34.4°, corresponding to the 002 and 004 planes, respectively. This is due to the large amount of amorphous regions present in cellulose, and also to the presence of amorphous lignin and hemicelluloses, which agrees with the results of other authors.

The immobilization of anthocyanin in the complex induced the appearance of new small peaks that may be ascribed to anthocyanins.

The most relevant aspect is that, in the case of flax supports (reference and grafted with MCT-β-CD), a certain level of cristallinity should be noticed, which is due to the small peaks that appeared.On the contrary, the XRD patterns characteristic of the colored samples show less pronounced peaks, meaning that the content of amorphous regions tended to increase in most cases.

Fig. 5.42: XRD patterns for flax fiber supports dyed with Allium cepa anthocyanin extract (Coman et al., 2014)

FT-IR spectroscopy analysis

The FT-IR analysis results of the reference flax supports and those treated with the MCT-β-CD solution of 10 g/L are shown in Figure 5.41.

The obtained FT-IR spectra of the reference flax supports showed peaks with very low intensity around 1646.7 cm-1 and with higher intensity around 3555.6, 2900 cm-1, corresponding to NH2, OH and CH2 stretching vibration, respectively. The absorption band that occurred in all spectra at 3450 cm-1 corresponds to the OH bond (intermolecular hydrogen bond). The maximum absorption at 1710 cm-1 is assigned to the carbonyl group (Abraham et al., 2011).

The occurrence of some bands characteristic of both host and guest species in the spectrum, which are usually shifted, compared to pure component bands, can be considered as evidence of the formation of an inclusion compound.

In the case of MCT-β-CD treated flax support, the significant difference from the reference vegetable fibre was that the characteristic band of triazinyl appeared with significantly higher intensity. This was attributed to the triazinyl nucleus υ(C=N), namely at 1572 and 1455 cm-1, which was successfully introduced and attached to the flax fibre. The triazinyl group (C=N) could react with the dye molecule more actively than the hydroxyl group (OH). The obtained FT-IR spectra also confirmed the grafting, from a qualitative point of view. The absorption peak at 1728 cm-1 is attributable to the stretching vibrations of the carbonyl group. The band at 1636 cm-1 can be attributed to the C = N valence vibration (or, possibly C = O in aldehydes and carboxylic groups). The C = C valence vibration is weak and often not visible. The 1335-1316 cm–1 doublet is assigned to the cellulose component. There is an absorption band present at 1200 cm-1, which is assigned to the vibration of C-O. The deformation beyond the double bond plan from the lateral catena is highlighted by the bands at 780-790 cm-1.

The use of the FT-IR technique allows the detection of complex formations in the solid phase. It also makes it possible to point out the implication of the different functional groups of guest and host molecules in the inclusion process by analyzing the significant changes in the shape and position of the absorbance bands of the natural dye, MCT-β-CD, physical mixture and inclusion complexes.

The MCT-β-CD exhibited a significant FT-IR peak at wavenumbers 942, 1094, 1166, 1337, 2929 and 3467 cm-1, while the natural dye showed FT-IR peaks at wavenumbers 1059, 1102, 1161, 3362, 3434 and 3464 cm-1.

The chemical changes occurred onto textile fibres surface as a result of peptides functionalization can be highlighted by Uv-Vis and FT-IR spectroscopy. The most representative absorption bands are as follows: 880.31, 1047.15, 1398, 1637 cm-1.

In case of referring to ligno-cellulosic support-β-ciclodextrin–extract of amarena cherries composite, the wavelengths values and their assignments to β-CD, natural colorant extract and β-CD/colorant natural inclusion complex onto bast supports can be explained due to the same vibrational modes (Fig.5.43). The use of FT-IR technique permits us to detect the complex formations in solid phase and to show the involvement of the different functional groups of guest and host molecules in the inclusion complex formation by studying the significant changes in the shape and position of the absorbance bands of natural dye, β-CD, and inclusion complexes.

Fig. 5.43: FT-IR peaks of the solid natural dye,β-CD, and inclusion complex (Coman et al., 2013).

BET results

As to their structure, natural fibers like flax can be considered as non-porous solids, and therefore, one should expect, according to Brunauer (Brunauer, et al., 1940) an adsorption isotherm of type II (for non-porous solids) out of the 5 classes. Nevertheless, regarding the studied samples, the performed BET measurements highlighted only the sorption-desorption behavior of both MCT-β-CD and dye molecules. Thus, Figure 5.44 showsthe nitrogen adsorption-desorption isotherms for the dye-molecule inclusion complex, considered as a mesoporous material. The studied sample displays a typical type IV isotherm with a hysteresis loop, which is characteristic of mesoporous materials, according to the IUPAC classification (Rouquerol, et al., 1994). The hysteresis loops have sharp adsorption and desorption branches, indicating a narrow mesopore size distribution and a good quality of the sample.

Fig.5.44: Nitrogen adsorption/desorption isotherm and pore size distribution (inset picture) of the he MCT-β-CD sample (Coman et al., 2014)

Fig.5.45: Nitrogen adsorption/desorption isotherm and pore size distribution (inset picture) ofβ-CD sample (Coman et al., 2014)

The observed decrease in surface area, pore diameter and pore volume is a proof that the dye molecules are located inside the pores/cavity of MCT-β-CD.

According to Table 2, the decreases in surface area, from 749.5 to 644.37, in pore diameter, from 7.15 nm to 5.3 nm, and in pore volume, from 1.42 to 0.88 cm3/g, are due to loading/incorporation of pigment molecules within the pores of the MCT-β-CD host support, which causes contraction ofthe nanopores by bridge-bonding of dye species, involving different functional groups of guest and host molecules in the inclusion process.17the dye molecule and the cavity of MCT-β-CD.

Color fastness analysis

The best coloring results, in terms of fastness properties, were obtained by inclusion of the natural dye inside the MCT-β-CD (Table 5.12). In other words, colour fastness improved after flax fabrics were grafted. The reason for this is that MCT-β-CD has a toroid shape with a hydrophobic central cavity and a hydrophilic outer surface, where the hydroxyl groups are located (Ramachandran et al., 2004). Thus, the dye molecules are bound to the MCT-β-CD, which explains the good stability in terms of color fastness.

Table.5.12. Values of surface area, pore diameter and pore volume for the studied samples (Coman et al., 2014)

Table 5.13.Colour measurements and colour fastness values for samples dyed with Allium Cepa Anthocyanin extract (Coman et al., 2014)

Fig.5.46: Changes in colour, saturation and hue for the samples dyed with anthocyanin extract, using standard and sonication dyeing procedures (Coman et al., 2014)

Fig.5.47: The a*b* diagram for the investigated specimens non-functionalized and functionalized with MCT-β-CD and dyed by standard and sonication procedures with the natural extract (samples 1, 2, 3, 4, 5, 6, 7, 8) (Coman et al., 2014)

The colours of the studied samples are somewhat modified. The coloration fastness is definitely upgraded. According to Figures 5.46 and 5.47, a reduction of brightness is recorded. The cause could be the design of the polymer–natural dye inclusion compound. An expansion in the saturation and darkening of the specimens, especially, of those non-functionalized and colored, as well as deviations of shades to the red-yellow color as regards the reference samples, is inspected.

After the thermal dyeing treatments that the samples were subjected to, the color changes in the samples treated with MCT-β-CD were considerably lower than in the untreated samples dyed with the same natural dye. For the non-grafted and colored samples, the color changes were major, probably due to a superficial deposition of the anthocyanin extract onto the fabric surface. In the case of the grafted samples, one can appreciate that by the embedding of anthocyanins in MCT-β-CD, color differences became less noticeable (Sarkar & Seal, 2005).The results clearly show that coloring is, to a certain extent, more resistant when the anthocyanin extract is applied onto grafted specimens, especially at higher concentrations. It is well known that poor wash fastness has been one of the main inconvenience of natural dyes. This aspect could be a weak point of the present research. In our investigation, the conjunction of the anthocyanin-based dye to the monochloro-triazinyl-β-cyclodextrin (MCT-β-CD) used as inclusion compound, was found to be efficient in increasing and stabilizing the colour fastness.

Regarding dyeing of samples by ultrasounds, the deviation of an intense hue is noticeable, as well as an even distribution of dye, in comparison to the standard coloration procedure.

The red shade of the coloration becomes more visible through the increasing of the a* coordinate from the CIELAB system for the functionalized and ultrasonically dyed samples (samples 6 and 8), as compared to the reference ones (samples 5 and 7), being a proof of the coloring intensity augmentation with the natural colorant, along with the increase of concentration. The decrease in the L* luminosity for the functionalized and ultrasonically colored samples at a high concentration and also the augmentation of the C* saturation represent an enhancement of the dyeing, compared to the standard protocol.(Milijkovie et al., 2007)

It can be concluded that, following the experiments, for a brief time and normal coloration temperature (15 min, 30 °C), an intense colour was achieved by the sonication assisted procedure, compared to the standard coloring method (30 min, 80 °C).

This idea is emphasized by the present research, by using a natural dye applied on a lignocellulosic support functionalized with monochlorotriazinyl-β-cyclodextrin (MCT-β-CD). Thus, one can identify a potential industrial application, by decreasing the thermal energy and coloring duration, involving a reduction in process costs.

Coloration performance for the samples dyed with colored matter was characterized in terms of colour fastness to washing, wet and dry rubbing, and with respect to the colour value of the CIELAB system with the 10˚ standard observer and illuminant D65. The specimens used as references are indexed as “non-treated flax” for all the measurements of non-functionalized and standard dyed samples and flax/(MCT-β-CD) for functionalized and colored by the two procedures. Thus, the E* colour differences are very substantial for the reference samples (samples 2, 4, 5, 7) by quantifying the un-dyed samples, leading to the idea that the fibres are easy to dye, they gather the natural colorant, but lose it through washing and rubbing, providing average fastness.

The natural dye deposited by complexation onto grafted samples is more stable, with smaller colour differences (samples 1, 3, 6, 8), but superior fastness values. Meanwhile, the ultrasonically colored specimens have enhanced/improved chromatic features, meaning the darkening of the shade and augmentation of saturation (samples 5, 7 and 6, 8), as compared to the standard dyed samples (samples 1, 3 and 2, 4).

The good values for dry rubbing and washing fastness (0.5-1) for functionalized and colored samples (samples 1, 3, 6, 8) are well supported by the fact that a dye-cyclodextrin complexing agent was formed; in this way, the dye molecule was stabilized inside the cyclodextrin cavity. This positive finding of the study has already been reported in the literature, with respect to direct and azo disperse dyes forming inclusion complexes with cyclodextrins (Voncica & Vivod, 2013). An improvement in the dyeability of the vegetable fibre supports, due to higher activity of the triazyne group, compared to that of the hydroxyl group (-OH) of raw vegetable fibre, resulting in an increased reaction probability between the dye molecules and the lignocellulosic fibres. The modification technique could be adapted to industrial scale flax dyeing, with satisfactory levels of dye-fiber interaction and fixation.

Besides, by this research the assisting effect of the ultrasonic power on the dyeability of flax fabrics colored with a natural extract is emphasized once more and can be explained by facilitating the dye–fibre contact and accelerating the interaction or chemical reaction between dye and fibre (Kamel et al., 2009). The proposed alternative coloration methodology, provided more intense shades, under conditions of short dyeing times and reduced temperatures (30°C).

In addition to the specified references, the current study promotes the innovative character of the coloring process with the natural red onion extract by ultrasounds powered technique, in order to develop novel solutions that are both more ecologically and economically sustainable.

By this study, an outline of the MCT-β-CD– dye complex formation on the functionalized textile has been made. The research has not eliminated the alternative of the connection of dye molecules around the MCT-β-CD cavity, based on the core–shell principle. Perspective researches will expose the counteraction mechanism of the natural dye. Subsequently, advanced studies will be focused towards “clogging” the dye molecule inside the MCT-β-CD cavity, or, on the contrary, the deposition of colorant onto the MCT-β-CD shell.

CHAPTER 6. CONCLUSIONS

Diana Coman, PhD,“Lucian Blaga” University of Sibiu, Romania

Narcisa Vrînceanu, PhD,“Lucian Blaga” University of Sibiu, Romania

The ultra sounded dyeing of textile polymeric supports with coloured extracts from black currant fruits and green walnut shells extracts without or with mordants assistance shown very good fastness for all fabrics. Nevertheless the polyamide fabric dyed by employing mordant agents, meaning 3% CuSO4 and 3% citric acid had poor values of fastness.

The conventional mordant compound – CuSO4has not clearly influenced the colorfastness to rubbing, but in case of using 5% concentration of tannic and citric acids, the colorfastness augmented.

The chromatic features of the colored specimens are distinct, regarding the type of the used biomordant. However, there is a certitude that the option of utilizing citric and tanic acids as coloring bioassistants conducted at a significant colour fastness.

The outcomes induce the idea that US assisted dyeing improved the dye molecules diffusion, thanks to the cavitation effect, when compared to the conventional treatments. In addition, the obtained results sustain the synergic effect given by the US energy and biomordant employment which positively influence the dye molecules entrapment. Moreover, fastness properties to washing and rubbing were slightly enhanced.

There is a connection between the occurrence of these naturally colored textile supports and the prevention of the development of bacteria onto them.

Meanwhile, it can be stated that these natural extracts represent valuable resources that recommended them for the textile eco-dyeing industry.

Future researches will focus onto the optimization of ultrasound powered coloration, by employing both another fibrous supports and natural extracts. The utilizing of natural dyes is an eco-alternative and may offer many benefits, like attractive shades of colors, antibacterial, deodorizing, hygienizing and UV protective properties. This aspect will be improved by new contributions for the future applications in the research field.

The final objective of the study can be identified within the background of the strategy of natural polymeric supports, functionalized by the addition of some performing attributes of some bioactive compounds extracted from vegetal sources, under the conditions of an ecologic dyeing methodology, by using natural extracts and biomordants providing the augmentation of antimicrobial response od textile support, with minimal chromatic changes.

The correlation between the fixation agent belonging to natural dye and inhibition area of treated samples is associated to a linearity with respect to the biomordant quantity and, consequently to the eco dye mass accelerating the coloring.

The chromatic attributes of dyed samples are different in terms of the used mordant, but undoubtedly it can be stated an alternative utilization of CA and TA, within the ecologic dyeing, as well as the assignment of antimicrobial behaviour to the polymeric supports with the adding value in the area of hygiene and healthcare.

This monograph revealed the efficiency of juglone extraction protocol in an aqueous medium, from green walnut shells, through a complex system of investigation: HPLC, IR-Raman, and Surface Enhanced Raman Spectroscopy (SERS), preserving the high purity active natural dye molecule from nut shell (juglone), even under the conditions of an extraction performed in a water-ethanol solvent medium. Secondly, the book envisages the application of these above mentioned dyes onto natural and synthetic substrates, making a correlation between their colour attributes and the fibrous composition of the substrates they are applied on. HPLC chromatography reveals an efficient ecologic extraction procedure. Besides, the refluxing duration in the experimental protocol of juglone extraction in water-ethanol solvent medium, from nut shells is almost the same with that belonging to synthetic juglone. It can be assumed there is a correlation between polymeric supports – coloration stability/color intensity. The woolen samples have higher colour intensities, fact sustained by the specific surface of the fibres compared with polyamide fibre consequently; the dye molecule is protected/preserved by the wool fibre morphology. It is realistic to presume that the histo-morphological profile of wool fibre provides the dye stability inside it. This aspect is more pregnant if biomordants are used. Regarding the FT-IR and Raman spectra, they are completely different, in terms of bands intensity. However, similitude occurs with respect to bands frequencies, in most cases, when we compare two spectra. The strongest bands, from the region specific to double bond (1700-1400 cm−1) suggest the essence of double bond shift, in case of the natural dye, compared to the standard juglone. The strong bands are noticed, not only at double bond, but also within the IR 300 cm–1 – 1000 cm–1 domain of SERS. This research is a key point in the identification of potential technological alternatives applied in ecologic finishing of synthetic and natural textile supports, quantified and controlled by colorimetric response/ attributes.

According to the findings of the investigations, the book is an environmental approachof stressing the reducing of negative impact as a result of classic dyeing processes in textile manufacturing. The results collected by means of the analytical techniques, i.e. the SEM, FT-IR spectroscopy and BET, showed that the ultrasound technique is more useful in enhancing the dyeability expressed in terms of K/S values than the conventional coloring method.

Due to the entrapping of dye molecule inside of MCT-β-cyclodextrin in nanocavity, the K/S value shows abrasion strength. Comparing the colour fastness values and the abrasion behaviour, the results indicate fair to good fastness of the functionalized and colored samples using both coloration methods.

The ultrasonication assisted method appears to be sustainable in the process of natural extract dyeing and will be used as preliminary to a natural coloration protocol development for eco-safe textiles.

The research proves to be more an effective no polluted approach and it can be used for a specific development of eco-performing textiles methodology with potential applicability in the textile industry.

Earlier studies demonstrated the benefits provided by the assistance of polycarboxylic acids in coloring, due to their capacity to improve certain properties of textile products, including wet tensile and compressive strength, but the most important is their ability to consolidate the bond between natural dye and fiber.

The experimental results included in this monograph revealed that the modified dyed vegetable fibers by inclusion technique can enhance the usual procedure for obtaining sustainable composites with better performances and durability, in terms of resistances to washing treatment, friction and abrasion. The durability is strong connected to the functional properties/treatment, mainly environmentally benign alternative.

The applied standard tests of wash, rubbing and abrasion fastness (shade change and staining) showed that black cherry extract dye was entrapped within the MCT-β -CD molecule. In light of this, and due to the results obtained by the previous studies, the dyeing method using enclosure of a natural dye in the MCT-ß-CD, could be a more promising way, because it can obtain textile products with enhanced fastness to washing treatment, friction and abrasion performance of composites cores and attributes, over the traditional mordant coloring technique.

FTIR and BET isotherms of the flax fabrics–MCT-β-cyclodextrin-black cherry extract dye composite showed changes compared with the samples colored with the assistance of CA, as well as a greater stability of host-guest complex consisting in anthocyanins embedded in MCT-β-cyclodextrin, with high efficiency in natural textile coloration procedure, which make the method feasible from an industrial perspective.

The present report describes novel methods to provide antimicrobial performance to different polymeric matrices by applying an innocuous and ecological promoter – L- Cysteine, a natural component never approached previously like a possible bio reactive assistant for fabrics and knitting contributing with antibacterial attributes without cytotoxicity. The considerable benefits of this method are as follows:

inoffensive both for the possible users and for the environment;

the high bioavailability once immobilized on wool;

persistance.

Additionally, since L-Cysteine represents a section of numerous living structures it is not foreseen to induce bacterial protection. These contexts are absolutely new and interesting for the functionalisation of polymeric matrices with AMPs which can grant compelling antimicrobial response in opposition to a large spectrum of microorganisms.The presented antibacterial methodologies will be able to open new viables perspectives for the medical area, and extended for other applications of textiles both in the sanitary and technical fields.

The K/S value of a dyed material at 300-700 nm was varied in direct proportion to the amount of dye absorption in the fabrics. The non-grafted colored fabric was used as reference. The K/S values increased from 6.1 to 7.20 as the sonic intensity was increased from 30 to 90 (50 to 60 Hz alternative current to electrical energy of high frequency). It should be noted that dyeing after ultrasound powered procedure with medium volume yielded in all cases darker colors, as is concluded from color measurement for the corresponding colored fabrics.

The book shows some relevantfacets, as follows:

a valuableentrapment of dye into monochlorotriazinyl-β-cyclodextrin (MCT-β-CD);

BET isotherms endeavourtreasureddata regarding the opportunity of the active sites to the adsorbate, meaning the inclusion compound (MCT-β-CD-pigment)design, resulting in good adsorptive response of the samples;

an adequate hindering of the pigment molecules into the graft polymerization agent’s cavity (MCT-β-CD), understanding a lasting coloring, explicited in colour intensity values;

a large amount of dye extract adsorbed at equilibrium (low ultrasonic volume) due to the active nanocavities available.

The outcomes achieved by this green surface design will devote to novel key points in population health and security sector, as alternatives for healthy natural polymeric matrices. As a conclusion, the dyeing achievement was owed to a synergic effect of anthocyanin natural colorant blocked into the cavity of MCT-β-CD and the sonication option for coloring.

From our examination of the fastness and dye uptake properties resulting from the use of MCT-β-CD as a inclusion compound, we concluded that the natural wild black cherry dye can provide good fastness, with the exception of the normal color change of washing and wet rubbing fastness. After coloration, the visual color was naturally darker and duller, which was attributed to the higher K/S value. Color fastness (washing, dry and wet rubbing) of all dyed fabrics was in the range of 2nd-5th grades. The efficiency of sonication assisted coloring was reported to be higher than that of standard method. The samples colored examined exhibited good wash fastness and potential for health and safety issues. Selected natural dyes would therefore be valuable for the dyeing of sheets and gowns for hospital use, and on articles which are less suitable for occupational health sector. A constant and growing tendency in terms of textile items with medical properties reducing the microbial attack was noticed. The described process prove to be more eco-friendly in nature and it can be used for specific product development in healthcare and hygiene applications, being compulsory a modeling of methodology, which will constitute a perspective research.

The following conclusions can be drawn:

A viable green-coloration approach was realized, coupling the non-conventional energy type, like ultrasounds, and the synergy between monochlorotriazinyl-β-cyclodextrin and the anthocyanin extract, in the interest ofachieve coloured polymeric matrices.

Polymeric vegetable matrices were profitably colored with red onion anthocyanin extract in fusion with MCT-β-CD, which is a remarkably inoffensive polymer providing good color fastness properties to the polymeric matrices.

The research regarded an advanced natural coloring methodology, with and without the employment of the MCT-β-CD agent. Following the graft polymerization with MCT-β-CD, the dyeing with natural extracts determined a loss of the crystallinity of polymeric vegetable matrices, but upgraded the fastness features of the modified supports.

Nevertheless natural polymeric matrices such as flax are regarded as non-porous solids, the investigation overstresses the concept of the mesoporosity of the inclusion complex attained by enveloping the dye molecules within the MCT-β-CD cavity. The detected reduction in the surface area, pore diameter and pore volume constitutes a confirmation that dye molecules are stroke in the inner part of the pores/cavity of β-CD.

The enhancement of the coloring methodology by applying the anthocyanin extract of Allium cepawas associated with the assistance of MCT-β-CD, acting like a graft polymerization agent for the polymeric vegetable matrices.

As a futureway to our study in the area of textile coloration, the surface functionalization with MCT-β-CD of polymeric matrices as initial treatment, accomplished for new natural dyes and pigments, will satisfy health-endorsing gains and environmentally securing effects.

Hence, the employment of MCT-β-CD–natural dye extract inclusion compounds is advanced by both green (a decreased pollutant charge) and industrial senses

According to the results of the investigation gathered by this monograph, from bast supports grafted with β-cyclodextrin and dyed with natural extracts such blackberry and bilberry anthocyanin extracts, the study is an environmentally option to stress the reducing of negative impact due to dyeing processes in the textile manufacturing. Regarding the future prospects, the present study outcomes will be used as preliminaries for a natural coloring protocol development for eco-friendly and non-toxic textiles.

Food and non-food products enriched with natural extracts of anthocyanins known for their strong antioxidant capacity are in accordance to the consumer's demand for natural colorants and in accordance to the new environmental considerations in marketing textiles. The use of natural dyes of anthocyanin structure may provide also beneficial effects on human health.

In the future, anthocyanins will still prove their valuable properties in particular through exploiting genetic and biotechnological techniques (cell cultures and tissues) to improve their accumulation in plants, proving efficiency and productivity in many competitive sectors (food, health, industry). Probably this direction will prevail in the coming decades as a result of a drastic decline in traditional plant resources as a result of the concerted action of several factors (disturbances of the ecosystem, unrestricted exploitation, increasing labor costs, problems regarding the cultivation of wild plant species, etc.). The socio-economic impact should not be neglected, the in vitro culture techniques being rapidly adapted to the market requirements.