Synthesis and Characterization of Aqueous Chitosan-polyurethanes Dispersion for Textile Applications with Multipurpose Performance Profile

As the use of high performance textiles has grown, the need for chemical finishes to provide the fabric properties required in the special applications has grown accordingly. In this project, a series of water dispersible polyurethanes dispersion (CS-PUs) with multipurpose performance profile was developed using isophorone diisocyanate (IPDI), polyethylene glycol (PEG), 2,2-dimethylol propionic acid (DMPA) and chitosan (CS) for textile applications. In two step synthesis process, NCO functional PU prepolymers prepared by reacting IPDI, PEG, and DMPA were extended with varying molar quantities of chitosan followed by structural characterization through FTIR. The prepared CS-PU dispersions were applied onto the dyed and printed poly-cotton blend fabrics. The performance behavior of the treated fabric in terms of crease recovery, tear strength, tensile strength, and antibacterial properties was evaluated by applying standard test methods. These investigations show that the CS-PU dispersions can be applied as antibacterial textile finishes with significant improvement in the physical and mechanical properties of poly-cotton fabrics.     

Preparation of carboxymethyl cellulose superabsorbents from waste textiles

Production of superabsorbent polymers from cotton and viscose waste textiles was investigated. The cellulose wastes were carboxymethylated, crosslinked by divinylsulfone, and then converted to superabsorbent material using air-drying, freeze-drying, or air-drying after phase inversion. The separation of cellulose from synthetic polymers in the textile (polyester) was carried out by direct dissolution of cellulose in N-methylmorpholine-N-oxide (NMMO), or separation by dissolution in water after carboxymethylation of the textiles. The progress of the carboxymethylation reaction was evaluated by measurement of the degree of substitution (DS) of carboxymethyl cellulose (CMC). The DS values of 0.50–0.86 confirmed the prosperous substitution of hydrophilic carboxymethyl groups into the cellulosic chains. The water binding capacity and the swelling rate of the superabsorbents prepared under different conditions were measured. Under the best condition the superabsorbent obtained from waste textiles showed an ultimate water binding capacity of 541 g/g which was notably higher than that of the reference superabsorbent derived from cotton linter (470 g/g). The amount of absorbed water by this product exceeded that of the reference sample after 60 min immersion.     

Odour control studies on apparel fabrics finished with methanol extract of Terminalia chebula

This study aimed to analyse the odour retention characteristics of different textile fibers. The commercially used textile fibers like cotton, viscose, linen, nylon, 60/40 cotton/polyester and 100 % polyester swatches were used as a sweat absorbing material in vests and T shirts. The In-vivo wear analysis was carried out with sedentary and non-sedentary workers. The worn samples were collected and subjectively analysed for the odour intensity after 24 hour storage at normal atmosphere. The subjective analysis result reveals that, highest amount odour intensity is in polyester. The intensity level in the following order: polyester>nylon>cotton/polyester>linen>viscose>cotton. Methanolic extract of Terminalia chebula was applied on the textile material to analyse the odour reduction ability. The subjective analysis results revealed that, the odour formation in the textile material reduced significantly after Terminalia chebula finishing process invariantly with fiber except nylon. To confirm the odour reduction objectively, bacterial isolation studies were performed with the treated and untreated worn samples. The results revealed that, the amount of bacterial colony in the finished textile reduced considerably than the worn untreated samples except nylon. Further, FTIR studies confirmed the reduction of odour forming short chain fatty acids in the treated worn textile than the untreated. Agar diffusion test results of finished textile, against major odour causing bacteria in axilla shows zone of inhibition up to 42 mm for all the fibers except nylon fabric. Hence, this study suggests a promising application of natural herbal finish for the odour reduction in apparels.     

Synthesis of core-shell fluorinated acrylate copolymers and its application as finishing agent for textile

Core-shell fluorinated acrylate copolymers emulsion was thus synthesized via the core-shell emulsion polymerization with the fluorinated monomers and acrylic monomers as the main raw materials and its properties were studied. PFMA, the fluorinated acrylate monomers, was synthesized by the esterification of perfluorooctanoyl chloride (PFOC) and hydroxypropyl methacrylate (HPMA). Then the core-shell fluorinated acrylate copolymers emulsion with a poly(MMA/BA/St) core and a poly(PFMA/MMA/BA) shell was synthesized via a starved semi-continuous core-shell emulsion polymerization method by using KPS and sodium bicarbonate as the initiator/buffer system and SDS/Twain 80 as the commixture emulsifier. Lastly, the synthesized copolymers was applied as textile finishing agent for cotton textile. The results of FT-IR and NMR indicated that PFMA had been synthesized as expected and effectively combined in the emulsion copolymerization. The GPC, zeta potential, TEM and DSC showed that the particles had uniform spherical core-shell structure with a diameter of 65-150 nm, and the distribution and emulsion stability was satisfactory. As XPS, FESEM and AFM shown, a hydrophobic structure which was similar to the structure of the lotus leaf were formed and the surface hydrophobicity of the films can be improved. Based on the analysis of DSC, thermal stabilities of the films were enhanced with the increase of fluorine content. Besides, FESEM of textiles showed that the surface of treated textiles were smooth and the edges were clear and visible, indicating significant improvement of the performance on water and oil repellent.     

Durable antibacterial cotton modified by silver nanoparticles and chitosan derivative binder

This article focuses on the functional finishing of textiles using silver nanoparticles (AgNPs) and chitosan derivative binder, which was synthesized by a modification of chitosan using α-ketoglutaric acid. The binder covalently linked to cotton fabric via esterification of the hydroxyl groups on the cotton surface, and tightly adhered to surface of the AgNPs by coordination bonds. As a result, the coating of AgNPs on the cotton fabric showed excellent antibacterial property and laundering durability. After 30 consecutive laundering cycles, the Ag content on the fabrics decreased to 37.6 %, but the bacterial reduction rates against both S. aureus and E. coli were maintained over 95 %. It has potential applications in a wide variety of fields such as sportswear, socks, and medical textile.     

Nylon textiles grafted with chitosan by open air plasma and their antimicrobial effect

Chitosan is a natural non-toxic biopolymer and is widely used in various fields because of the antimicrobial activities. In this study, the properties of nylon textiles grafted with chitosan oligomer or chitosan polymer after being activated by open air plasma were evaluated. Results showed that nylon textiles grafted with chitosan polymer had better antibacterial performances than those grafted with chitosan oligomer. Air plasma activation at a higher speed (26 m/min) for a few times facilitated the grafting of chitosan and critically determined the antibacterial activities. Further treatment with air plasma after grafting improved the antibacterial effect. Overall, chitosan-grafted nylon textiles showed good antibacterial potential as well as biocompatibility.     

Impregnation of zinc oxide mediated chitosan nano-composites on polyester fabric for performance characteristics

Present study dealt with the fabrication of chitosan/zinc oxide nano-composites (CZNCs) using a facile preparation method. The structural features of nano-composites were investigated by using advanced analytical techniques. The developed nano-composites exhibited hexagonal structural pattern with an average particle size of about 51 nm. The developed CZNCs were dispersed in 2-propanol and applied on polyester by using the pad-dry-cure method. The treated fabric specimens were characterized for surface, functional and textile properties including antibacterial activity and (ultra violet) UV- blocking. The nano-composite treated polyester fabric exhibited durable antibacterial, UV- blocking and textile properties with fair whiteness index.     

A new application method of chitosan for improved antimicrobial activity on wool fabrics pretreated by different ways

Antimicrobial treatments have become more important for the textile materials especially used in sportswear, activewear, and casual wear since they can easily be contaminated by perspiration leading to bacterial growth and body odor. In this work, antimicrobial activity of chitosan in a silica matrix on pretreated wool fabrics was studied. The pretreatment processes were applied by two different ways (enzymatic and enzymatic+hydrogen peroxide). Afterwards chitosan solutions were applied to the untreated samples and to the samples that were pretreated by two different ways to give antimicrobial effects. The antimicrobial activity of wool fabrics treated in various methods was assessed before and after repeated washings (up to 10 cycles) by the application of standard test method AATCC 147-1998. The morphology of the treated fabrics was investigated by SEM and their characterizations were made by the FT-IR spectral analysis. Results revealed that pretreatment ways and chitosan application methods were quite important for adsorption and diffusion of chitosan on wool fabrics and washing stability. From the SEM images, it was clearly observed that pretreatment processes caused some degradation on the surface of the fiber; but combined processes were found to be less degradative and more effective.     

A comprehensive study of silicone-based cosmetic textile agent

In recent years, textile materials have also found applications in the cosmetic field as more and more commercial cosmetic textile agents are now available in the market. In this paper, one commercially available cosmetic textile agent (CTA) for skin caring benefits was used for making the cosmetic textiles. Systematic characterization methods were established to assess their performance in terms of material identification, fabric performance properties as well as biological safety and biological response to human skin. The experimental results showed that after the treatment of cosmetic textile agent, the fiber surface was covered with a thin layer of smooth material, thereby contributing several alterations to fabric properties and providing a better hand feel to human body. The durability of cosmetic textile was considerably satisfactory with respect to the abrasion resistance and washing cycles. The experimental results also illustrated that the cosmetic textiles might probably enhance the replacement of cells with the newly regenerated ones in the skin structure of human body, and thus provided a more efficient turning-over and replacement of skin components.     

Durable antibacterial cotton fabrics with chitosan based quaternary ammonium salt

A water soluble quaternary ammonium chitosan derivative, N-benzyl-N,N-diethyl chitosan quaternary ammonium salt (BDCQA), was prepared for antibacterial finish of cotton textiles. The effects of concentrations of finish agents and treatment time on the add-on ratio of cotton treated BDCQA (BDCQA-cotton) were studied in details. The morphology and thermal property of BDCQA-cotton were characterized by scanning electron microscopy (SEM) and thermagravimetric (TG) analysis. Gram-positive bacterium Staphylococcus aureus (S. aureus) and Bacillus cereus (B. cereus), Gram-negative bacterium Escherichia coli (E. coli) and drug-resistant bacterium Methicillin-resistant Staphylococcus aureus (MRSA), were used to evaluate the antibacterial activity and durability of BDCQA-cotton. The results showed that BDCQA-cotton possessed good antibacterial activity and high durability against broad spectrum bacterium. The preliminary investigation on the antibacterial mechanism was discussed in this work.     

Gold recovery using inherently conducting polymer coated textiles

The ability of inherently conducting polymer (ICP) coated textiles to recover gold metal from aqueous solutions containing [AuCl₄]⁻ was investigated. Nylon-lycra, nylon, acrylic, polyester and cotton were coated with a layer of polypyrrole (PPy) doped with 1,5-naphthalenedisulfonic acid (NDSA), 2-anthraquinonesulfonic acid (AQSA) orp-toluenesulfonic acid (pTS). Textiles coated with polyaniline (PAn) doped with chloride were also used. The highest gold capacity was displayed by PPy/NDSA/nylon-lycra, which exhibited a capacity of 115 mg Au/g coated textile, or 9700 mg Au/g polymer. Varying the underlying textile substrate or the ICP coating had a major effect on the gold capacity of the composites. Several ICP coated textiles recovered more than 90% of the gold initially present in solutions containing 10 ppm [AuCl₄]⁻ and 0.1 M HCl in less than 1 min. Both PPy/NDSA/nylon-lycra and PAn/Cl/nylon-lycra recovered approximately 60% of the gold and none of the iron present in a solution containing 1 ppm [AuCl₄]⁻, 1000 ppm Fe³⁺ and 0.1 M HCl. The spontaneous and sustained recovery of gold metal from aqueous solutions containing [AuCl₄]⁻ using ICP coated textiles has good prospects as a potential future technology.     

Carbon footprint reduction in the textile process chain: Recycling of textile materials

It is an important task of people connected with the textiles and clothing sector to work on the feasible ways to trim down the carbon footprint in each phase of a textile product??s life cycle. One of the possible ways to decipher the reduction of carbon footprint of textiles and clothing sector is to recycle the textile process waste and also to recycle at the end-of-life of textile products and these aspects are exemplified in this paper in detail. Detailed investigation of the possibilities, barriers, challenges to recycle textile waste materials are discussed in this paper with relevant case studies. For recycling of process waste, an example was modelled by recycling the process waste and the carbon footprint results were demonstrated with the aid of 7.3 version of SIMAPRO LCA (Life cycle assessment) software. From the results of this case study, it was understood that recycling of process waste would contribute to the direct reduction of carbon footprint. For the second case of recycling at the end-of-life, there are many barriers and challenges to the textile products to be recycled, which are discussed in detail. For this case, two hypothetical situations were defined and the carbon footprint results of them were modeled and demonstrated with the aid of 7.3 version of SIMAPRO software to illustrate the benefits of recycling to reduce the carbon footprint. Designers need to conisder, ??Ecological Design?? in design phase to address most of the difficulties faced by recycling of textile products at the end-of-life, which will of certain help to reduce the carbon footprint of the textile products.     

Putting function into fashion: Organic conducting polymer fibres and textiles

Textiles have traditionally been employed over the centuries with great utility in areas as diverse as fashion through to technical textiles. In all these instances the textile itself has been a structural element that once fabricated has limited utility beyond the intended structural and aesthetic application. In recent years there has been a shift towards the incorporation of electronic systems into textile structures. The new paradigm for textiles is the development of systems that not only provide the more traditional aspects of textiles but expands upon this to provide a unique capability to transmit and store information and energy. More importantly these next generation materials will be capable of responding to external stimuli, modifying features of the textile in a direct response to its working environment. A potential route to truly functional electronic textiles is through the application of conducting polymers.     

Eco-dyeing and antimicrobial properties of chlorophyllin copper complex extracted from Sasa veitchii

Cotton fabrics were dyed with the natural chlorophyll derivates (chlorophyllin, Chlin) after treatment with and without chitosan. The water-soluble Chlin extracted from Sasa veitchii based on Japanese bamboo leaves were investigated in order to improve the textile coloration and antimicrobial activity. The antimicrobial activity of the dyed fabrics that had been pretreated with chitosan as a biomordant over a concentration range of 0∼0.7 % was tested against two common gram pathogens: Staphylococcus aureus and Klebsiella pneumoniae. The color depth as measured by the K/S value, the color difference and the colorfastness to washing and light were also evaluated. The fabrics treated with chitosan resulted in an increase in dye uptake in all cases compared with the corresponding untreated fabrics, and did not affect fastness of washing and light. The cotton fabrics dyed with mordant and CuSO₄ extracts appeared to have over 99.9 % of antimicrobial activity, while MeOH extracts showed 71.8 %.     

Spectrometric identification of solvent extractable organic additives in polyester-based textile fibers

In this study, polyester-based textile fibers were treated with several liquid-solvents and the extracts were spectrometrically characterized. The solvents used were ethanol-ether (1:1), ethanol-HCl (1:1), and carbon tetrachloride. Spectrometric characterization of the extracts included a first study by UV-visible spectrophotometry, fluorescence spectroscopy, and Fourier transform-infrared spectrometry after a liquid chromatographic fractionation. However, final elucidation was carried out by liquid chromatography-mass spectrometry, which provides enough sensitivity, and fast and reproducible results. The organic compounds identified in the extracts were usual additives largely employed in the manufacture of textile fibers. Some of these organic compounds can constitute potential hazards for human health.     

Rheological behavior and spinnability of ethylamine hydroxyethyl chitosan/cellulose co-solution in N-methylmorpholine-N-oxide system

In this work, the novel chitosan derivative ethylamine hydroxyethyl chitosan (EHC) was synthesized and blended with cellulose in an aqueous N-methylmorpholine-N-oxide (NMMO) solution in order to fabricate antibacterial chitosan/cellulose fiber. The rheological behaviors of the obtained co-solution in both steady and dynamic states were carefully investigated to determine the spinnability of the co-solution. In steady state, the addition of EHC was found to preserve the power-law flow characteristics of cellulose in the aqueous NMMO solution, while broadening the first Newtonian fluid-flow area. Under dynamic conditions, both Han-plot and viscoelastic analyses indicated the homogeneity of the co-solution. EHC/cellulose antibacterial fibers were successfully spun via the lyocell process using aqueous NMMO as the solvent, confirming the excellent spinnability of the EHC/cellulose co-solution. Scanning electron microscopy was used to observe the morphology of the obtained EHC/cellulose fibers; they were also investigated for antibacterial activity. The obtained EHC/cellulose fiber exhibited good spinning consistency and strong antibacterial activity against Escherichia coli, demonstrating potential applications for the material in antibacterial textiles.     

Development of energy generating photovoltaic textile structures for smart applications

The aim of this study is to develop a method with lower application temperature and a device structure to obtain reproducible photovoltaic textiles. Two different kinds of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) solutions over a silver (Ag) layer was used as anode, a blend of poly(3-hexyl thiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) as light absorbing layer and a thin aluminum (Al)/Ag layer as semi-transparent cathode. These devices capable of generating electricity from sunlight were fabricated on polypropylene tapes that could be woven into a textile fabric. The short-circuit current density and power conversion efficiency of photovoltaic tapes were increased by using an Ag layer beneath the PEDOT:PSS electrode. The photovoltaic textile structure exhibited remarkable power conversion efficiency (0.29 %) by transmitting the light through the upper electrode. This approach may be used in industrial applications to develop photovoltaic textile materials.     

Antibacterial finishing of cotton fabric via the chitosan/TPP self-assembled nano layers

In this study, chitosan and pentasodium tripolyphosphate (TPP)-based bilayers were fabricated on the cationized woven cotton fabrics via layer-by-layer (LBL) self-assembly technique. The initial cationic charges on cotton fabric were produced through the aminization procedure involving the covalent attachment of reactive dye to cotton fabric and subsequent reductive cleavage of the dye to free amine. Different numbers of bilayers (1, 5, and 10) consisting of chitosan/TPP have been deposited on the fabrics. The surface morphology, cationic group content, chemical surface modification, whiteness index, surface tension and antibacterial properties of the modified cotton samples were investigated using scanning electron microscopy (SEM), methylene blue test, FTIR, reflectance spectroscopy, water contact angle measurements and antibacterial test, respectively. The bacterial inhibition experiments demonstrated that the modified cotton fabric with the addition of chitosan/TPP bilayers can increase the degree of inhibition on E. coli and S. aureus bacteria. The utilized LBL method was an easy and cost-effective procedure for developing of novel antibacterial textiles with the highly attractive feature in the medical and hygienic products.     

Plasma-assisted surface modification of polyester fabric for developing halochromic properties

In the field of textiles, introducing pH-sensitive dyes onto fibrous materials is a promising approach for the development of flexible sensor. In this study, poly(ethylene terephthalate) (PET) textile surface with halochromic properties was fabricated by plasma-assisted sol-gel coating, followed by immobilization of two different azo pH-indicator dyes; namely Brilliant yellow and Congo red by conventional printing technique of fabrics. 3-aminopropyltriethoxysilane (APTES) was used as a coupling agent for attaching the pH-sensitive dyes through its terminal amines. The surface immobilization of APTES on PET fabric was conducted by the pad-dry-cure method. Moreover, the influence of oxygen plasma pre-treatment and the method of post-treatment either by oxygen plasma or by thermal treatment on the stability of sol-gel based matrix was investigated. The morphology and chemistry of 3-aminopropyltriethoxysilane coated PET surfaces were examined by using surface sensitive methods including electrokinetic and time-dependent contact angle measurements as well as X-ray photoelectron spectroscopy (XPS). In addition, fastness tests of the printed fabrics and color strength were carried out to assess the effectiveness of the fabric surface modification. Results indicate that sol-gel matrix exhibited a more stability by thermal post-treatment at 150 C for 5 min. Also, the results revealed that the printed fabrics with halochromic properties demonstrated sufficient stability against leaching by washing. The current work opens up a novel opportunity to develop flexible sensors based on fibrous materials, which have the potential to be employed in variable industrial applications.     

One-bath one-dye class dyeing of PES/cotton blends after corona and chitosan treatment

In this work, the effects of corona discharge (CD) and chitosan treatment on the dyeability of polyester/cotton blends with direct and reactive dyes were studied. The surface chemical changes of polyester and cotton were analyzed using X-ray Photoelectron Spectroscopy (XPS). The correlation between chemical changes, wettability, and dyeability after CD and/or chitosan treatment has been established. Color intensity of both single components and PES/cotton blend increased proportionally with increasing chitosan concentration. The results obtained open the possibility for a new method for dyeing of polyester/cotton blends in a single bath using one dye-class that is commonly used for dyeing of textile material of cellulosic origin.