Smart Textile Materials by Surface Modification with Biopolymeric Systems

The aim of this study is to provide an overview of the possibilities of obtaining "smart" surface modifying systems (SMSs) based on biopolymer chitosan hydrogels, and to discuss the possible problems of obtaining “smart” textile materials by attaching these surface modifying systems to regular textile materials. Due to the fact that chitosan based, pH-sensitive, temperature-sensitive and temperature/pH dual-sensitive hydrogels are of special interest in designing "smart" textile materials, current developments in the preparation of chitosan based hydrogels are reviewed. However, since the main challenge of developing “smart” textile materials is confined to the techniques of successful attachment of the hydrogel layer to the textile substrate, strategies for successful attachment of “smart” hydrogels are presented. It is expected that this innovative strategy will enable creating of new enhanced textile materials, which not only contain fibres that maintain the advantageous and conventional properties but also advanced functionalities and/or environmental responsiveness implemented by modifying the very thin surface layer of the material

Microgel-based surface modifying system for stimuli-responsive functional finishing of cotton

An innovative strategy for functional finishing of textile materials is based on the incorporation of a thin layer of surface modifying systems (SMS) in the form of stimuli-sensitive microgels or hydrogels. Since the copolymerization of poly(N-isopropylacrylamide) with an ionizable polymer, such as chitosan, results in a microgel that is responsive to both temperature and pH, the microparticulate hydrogel of poly-NiPAAmchitosan copolymer (PNCS) was synthesized using surfactant-free emulsion method. The microparticle size in dry (collapsed) state is estimated at 200nm by SEM and TEM, and effect of temperature and pH on microparticles was investigated by DLS and UV–vis spectrophotometry. The incorporation of PNCS microparticles to cotton material was done by a simple pad-dry-cure procedure from aqueous microparticle dispersion that contained 1,2,3,4-butanetetracarboxylic acid (BTCA) as a crosslinking agent. This application method provided sufficient integrity to coating by maintaining the responsiveness of surface modifying system. The stimuli-responsiveness of modified cotton fabric has been confirmed in terms of regulating its water uptake in dependence of pH and temperature

Attachment of β-Cyclodextrins on Cotton and Influence of β-Cyclodextrin on Ester Formation with BTCA on Cotton

Cotton was treated with β-cyclodextrin (BCD) and two derivatives of β-cyclodextrin (2-hydroxypropyl-β-cyclodextrin and monochlorotriazinyl-B-cyclodextrin) to assess the optimal type for fixation with cotton. The experimental results showed that treatment of cotton with BCD using the crosslinker BTCA resulted in higher fixation than the treatments with the other two derivatives. The concentration of BTCA used did not significantly influuence the amount of fixation of BCD on cotton. FTIR-ATR spectroscopic analysis showed that the amount of ester formed on the fabric was influenced by the addition of BCD on cotton with BTCA in comparison to crosslinking of only BTCA with cotton. The laundering tests showed relatively poor washfastness of the β-cyclodextrins on the fabrics

Removal of metal cations from wastewater using recycled wool-based non-woven material

In this study, the effect of low-temperature air plasma, biopolymer chitosan and hydrogen peroxide treatment of recycled wool-based non-woven material on metal cation uptake was investigated. Recycled wool-based material either as an untreated or modified material showed ability to bind all investigated metal cations in the following order: Pb2+>Cu2+>Zn2+>Co2+. Material performed good selectivity due to distinct sorption rates of studied metal cations.U ovom radu je ispitan uticaj obrade netkanog materijala na bazi vune kao sekundarne sirovine niskotemperaturnom plazmom, biopolimerom hitozanom i vodonik- peroksidom na sorpciju katjona metala. Materijal na bazi vune kao sekundarne sirovine bilo kao neobra|en ili modifikovan, poseduje sposobnost vezivawa katjona metala prema slede}em redosledu: Pb2+>Cu2+>Zn2+>Co2+. Materijal pokazuje dobru selektivnost usled razli~ite brzine sorpcije ispitivanih katjona metala

Removal of metal cations from wastewater using recycled wool-based non-woven material

In this study, the effect of low-temperature air plasma, biopolymer chitosan and hydrogen peroxide treatment of recycled wool-based non-woven material on metal cation uptake was investigated. Recycled wool-based material either as an untreated or modified material showed ability to bind all investigated metal cations in the following order: Pb2+>Cu2+>Zn2+>Co2+. Material performed good selectivity due to distinct sorption rates of studied metal cations

Incorporation of poly(N-isopropylacrylamide)/chitosan microgel onto plasma functionalized cotton fibre surface

In the present study, non-thermal plasma treatments using three different gases (air, nitrogen and argon) were used to activate the cotton surface for subsequent poly(N-isopropylacrylamide)/chitosan microgel (PN/CS) incorporation. The different surface modifications obtained on cotton and their effect on the microgel incorporation were investigated using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It was found that PN/CS microgel particles with a diameter of 180 nm were tightly adhered to the cotton fabric surface. Nitrogen and argon plasma treated cotton presented better results in terms of microgel incorporation. The concept presented could lead to the development of a novel material with the highly attractive feature of responsiveness to the environmental stimuli

XPS and contact angle study of cotton surface oxidation by catalytic bleaching

Surface chemistry and wetting properties of cotton fibres as affected by catalytic bleaching have been investigated. Two types of cotton fabric have been analysed: the regular and a model cotton fabric. In the regular – double scoured cotton fabric, cellulose was contaminated with both non-removable and removable impurities including different pigments. The model cotton fabric, previously freed of most removable impurities, was stained for the purpose of this study with one pigment only, i.e. morin, a component that is typically found in native cotton fibre. Bleaching effectiveness of the catalyst based bleaches has been compared to the non-catalyst based bleaching systems. Surface chemical changes of cotton have been identified by XPS. Contact angle and capillary constant of the cotton fabric have been measured applying the Washburn method. This approach has provided the tool to explore and to quantify the chemical and physical effects on cotton fibre after catalytic bleaching. The interrelationship between an increase in capillary constant and the removal of non-cellulosic impurities, characterised by the C1 component in C 1s XPS spectrum, has been elucidated

Diagnostic Accuracy of Platelet Count and Platelet Indices in Noninvasive Assessment of Fibrosis in Nonalcoholic Fatty Liver Disease Patients

Objective. Keeping in mind the rising prevalence of nonalcoholic fatty liver disease (NAFLD) and the need to establish noninvasive tests for its detection, the aim of our study was to investigate whether platelet count (PC), mean platelet volume (MPV), and platelet distribution width (PDW) can predict the presence of liver fibrosis in this group of patients. Methods. In 98 patients with NAFLD and 60 healthy volunteers, complete blood counts with automated differential counts were performed and values of PC, PDW, MPV, and PCT were analyzed. Results. Patients with NAFLD had lower PC and higher MPV, PCT, and PDW compared to the controls (P < 0.05). When NAFLD group was stratified according to severity of liver fibrosis, there was a statistically significant difference in the average values of PDW and PC between the groups (P < 0.05). Conclusion. Patients with NAFLD have significantly higher values of PCT, PDW, and MPV when compared to the healthy controls. Further studies are needed to establish their potential use for prediction of the degree of liver steatosis and fibrosis in NAFLD patients