Search

This research presents a new procedure for the chemical modification of cotton fabric, which included a ‘’green’’ in situ synthesis of silver particles using an extract of sumac leaves as a reducing agent. To increase the adsorption ability of silver cations, a sol-gel matrix was previously created on cotton fabric using an organic–inorganic precursor sol-gel. The presence of silver particles on the cotton fabric was confirmed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that silver particles were created on the cotton fabric in the presence of the sumac leaf extract, which colored the fibers in brown. The presence of the sol-gel matrix increased the adsorption of silver cations and therefore the concentration of sliver particles, which resulted in a deeper color yield. Silver particles provided antibacterial protection, with a 99–100% reduction of E. coli in S. aureus bacteria, while the sumac leaf extract provided excellent protection against ultraviolet radiation, with an ultraviolet protective factor equaling 66.54. The coating was also highly durable in terms of its washing fastness.

This work examines the possibility of using leaves from the invasive plant species Fallopia japonica (Japanese knotweed) as a source of dye for the natural dyeing of cotton. To achieve a higher uptake of extracted dye, a cationic agent instead of a classical mordant was used to treat the cotton prior to dyeing. Distilled water and 0.5 M NaOH were used as extraction mediums to produce natural dyebaths with different concentrations (10, 20 and 50 g/L) of Fallopia japonica leaves. The colorimetric measurements revealed that a higher concentration of extract, the extraction of leaves in NaOH and a cationic pretreatment of cotton yield a dark-brown-coloured cotton with good wash stability.

Technical textile materials with multifunctional protective properties represent one of the largest and fast growing segments of the textile industry. Multifunctional water- and oil-repellent and flame-retardant coating on polyester (PES) fabric was prepared in this research using fluoroalkyl-functional siloxane (FAS) as the water- and oil-repellent finishing agent and organophosphonate (OP) as the flame-retardant agent. A finishing solution containing FAS and OP of appropriate concentrations was applied to the untreated and oxygen plasma-treated PES fabric samples using the pad-dry-cure method. For comparison, single-component FAS and OP finishing solutions were applied to the fabric samples under the same conditions. The coated PES samples were washed under standard conditions. The morphological, chemical and functional properties of the coated PES samples were determined with scanning electron microscopy, Fourier transform infrared spectroscopy, wet pick up, liquid contact and sliding angles measurements as well as oil repellence and vertical burning tests. The results reveal that oxygen plasma treatment prior to finishing significantly increased the wettability of the PES fibres, which directly resulted in increased concentration of the absorbed finishing agents. This treatment enabled the creation of PES fabric with simultaneous uperhydrophobic, oleophobic and flame-retardant properties. Although the superhydrophobic and oil-repellent characteristics of the coating were preserved after washing, the flame retardancy was hindered because of the removal of OP in the washing bath.

The influence of the treatment process on the dyeability of cotton fabric with a natural dye from goldenrod blooms was studied in this research. The dyeing was performed on untreated and treated cotton samples. The treating of the samples, using mordant (KAl(SO4)2 × 12 H2O), was performed before and during the dyeing process, whilst treatment with a cationic agent (Denimcol FIX-OS) was performed only before dyeing. The dyeing was carried out at 60 °C in two repetitions in three different concentrations of goldenrod aqueous extract, namely without dilution, and by diluting the extract with distilled water at volume ratios of 1:2 and 1:3. Spectrophotometric measurements were done before and after 1, 5, and 10 washing cycles. Colour fastness to rubbing was visually evaluated using a grey scale. Colour fastness to artificial light was visually evaluated using a blue scale, as well as spectrophotometrically before and after illumination of the dyed samples. The results of the research show that the cationic treatment of cotton fabric essentially influences on higher dye uptake in comparison to treatment using mordant before or during dyeing. Cotton samples that are treated with a cationic agent have the highest colour fastness to washing, rubbing, and light among all of the studied samples.

A new functional, stimuli-responsive microgel coating on polyamide 6 (PA6) fabric with simultaneous temperature (T)- and pH-responsive moisture management, UV protection and photocatalytic self-cleaning properties was prepared by applying poly-(N-isopropylacrylamide)/chitosan (PNCS) microgel in combination with ZnO nanoparticles to PA6 fabric. Two different application procedures were used: (i) the application of PNCS previously functionalized with a ZnO nanoparticles suspension and (ii) the application of PNCS with the subsequent application of a ZnO nanoparticles suspension. The coatings were fabricated on the untreated PA6 fabric as well as on fabric previously modified by the silica matrix created by the sol-gel precursor iSys MTX in order to increase the adsorption ability and uniformity of the coating. The chemical and morphological properties of the coated PA6 samples were determined by SEM and FTIR analyses. Stimuli responsiveness and functional properties were assessed by the moisture content, water vapour transmission rate, water uptake, UV protection and photocatalytic self-cleaning measurements. The results show that the application procedure as well as the pretreatment of PA6 fabric greatly infl uenced the properties of the coating. Accordingly, the most appropriate procedure included the creation of a silica matrix on the PA6 fibres followed by the application of PNCS and subsequent application of ZnO. In this case, the modified PA6 fabric exhibited high T and pH responsiveness due to the swelling/de-swelling activity of the PNCS microgel, as well as good UV protection with UPF equal to 18.8 and photocatalytic self-cleaning properties that are even higher than those in the case of the one-component coating with ZnO.

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.