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Cellulose produced by bacteria (BC) is considered a promising material for the textile industry, but the fragile and sensitive nature of BC membranes limits their broad applicability. Production of all-cellulose biocomposites, in which the BC is cultivated in situ on a cotton fabric, could solve this problem, but here a new issue arises, namely poor adhesion. To overcome this challenge, cotton fabric was modified with low-pressure oxygen plasma in either afterglow, E-mode, or H-mode. All-cellulose biocomposites were prepared in situ by placing the samples of cotton fabric in BC culture medium and incubating for 7 days to allow BC microfibril networks to form on the fabric. Modification of cotton fabric with oxygen plasma afterglow led to additional functionalization with polar groups, and modification with oxygen plasma in H-mode led also to etching and surface roughening of the cotton fibers, which improved the adhesion within the biocomposite. In addition, these biocomposites showed higher deformation capacities. Modification of the cotton fabric over a longer period in E-mode was found to be unsuitable, as this caused strong etching, which led to the defibrillation of cotton fibers and poor adhesion of BC. This study highlights the potential of low-pressure plasma treatment as an environmentally friendly method to improve the performance of cellulose-based biocomposites. [ABSTRACT FROM AUTHOR]

The aim of this research was to study the possibility of introducing a three-stage procedure for chemical modifi cation of textile fi bres to achieve antimicrobial properties as well as to determine the infl uence of the procedure on chemical, morphological and functional properties of fi bres and their degree of biodegradation.The procedure was applied to 100% cotton (CO) and 100% polyester (PES) fabrics and a CO/PES fabric blend with a ratio of 50%/50%. The procedure of chemical modifi cation included (i) pre-treatment of fi bres with oxygen plasma, (ii) application of organofunctional trialkoxysilane for the creation of a silica matrix, and (iii) in situ synthesis of silver chloride. For comparison, a silica matrix with incorporated silver nanoparticles was also created on the samples without plasma treatment. Untreated and chemically modifi ed samples were buried in soil for a defi ned period of time, and biodegradation of the fi bres was conducted. Chemical and morphological changes after chemical modifi cation and biodegradation were determined by microscopic and spectroscopic analyses, thin-layer wicking, and colour measurements. The results show that chemical modifi cation did not cause signifi cant morphological changes to the fi bres. Treatment with oxygen plasma increased the fi bre hydrophilicity, which resulted in an increased concentration of adsorbed silver. The presence of silver on the CO and CO/PES fabrics signifi cantly decreased the degree of biodegradation compared to the untreated samples. Plasma treatment increased the degree of fi bre biodegradation irrespective of the silver concentration present on the fi bres. The low degree of biodegradation of the PES fabric was more due to the high hydrophobicity and crystallinity of the fi bres than to the presence of silver.

Dyeing with natural dyes extracted from curcuma, green tea, avocado seed, pomegranate peel and horse chestnut bark was studied to evaluate the dyeability and ultraviolet (UV) blocking properties of raw and bleached/mercerised cotton fabrics. 20 g/l of powdered plant material was extracted in distilled water and used as a dyeing bath. No mordants were used to obtain ecologically friendly finishing. The colour of samples was measured on a refl ectance spectrophotometer, while UV-blocking properties were analysed with UV-Vis spectrophotometer. The results showed that dyeing increased UV protection factor (UPF) to all samples, however much higher UPF values were measured for the dyed raw cotton samples. The highest UPF values were obtained on both cotton fabrics dyed with pomegranate peel and green tea extracts, giving them excellent protective properties (UPF 50+). The lowest UPF values were obtained by dyeing cotton with avocado seed extract and curcumin. Dyeing with selected dyes is not stable to washing, so the UV-blocking properties worsen after repetitive washing. However, raw cotton samples retain their very good Uvblocking properties, while bleached/mercerised cotton fabrics do not provide even satisfactory UV-blocking properties. No correlation between CIE L*a*b*, K/S and UPF values were found.

Dyeing of raw and bleached cotton fabrics with a natural dye of curcumin was studied to implement the ancient and environmentally friendly technique of developing photos called anthotype. With the aim of achieving diff erent colours of dyed cotton fabrics, several modifi cations were performed, such as extraction of curcumin in hard and soft water, after-treatments of dyed cotton, i.e. with ferrous sulphate, zinc chloride and silver nitrate, aftertreatment in alkaline bath, and aftertreatment with other natural dyes (blueberry and raspberry). The colour values of dyed samples were determined using a refl ectance spectrophotometer. Colour stability to light was determined by the standard method in Xenotest. It was found that the use of various metal salts, natural dyes, alkalinity and hardness of water infl uenced the colour changes of the substrate. Yellow, red, greenish and brownish colours of fabrics were produced by diff erent treatments. Since the use of metal ions improved the stability of curcumin to light, the motifs produced by anthotype technique were hardly visible. It was found that the natural dye of blueberries and raspberries did not infl uence the light stability, therefore a larger colour contrast between exposed and unexposed areas of the fabric was visible, and consequently good visibility of the motifs was achieved.

The article focuses on the urgent need for green chemistry in developing high-performance textiles, aiming to reduce the environmental impact of production. It presents a new eco-friendly process involving the hydrothermal in-situ synthesis of Titanium dioxide (TiO2) in cotton fabric, combined with dyeing using turmeric extract to create a multifunctional textile with Ultra Violet protection and photocatalytic properties.

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Copyright of Tekstilec is the property of University of Ljubljana, Faculty of Natural Sciences & Engineering, Department of Textiles and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)