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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.

The introduction of green chemistry has become urgent in the development of innovative, high-performance functional textiles to reduce the environmental footprint of their production. This study aims to develop a new eco-friendly process for the hydrothermal in-situ synthesis of TiO2 in cotton fabric and dyeing with curcumin natural dye to produce a photocatalytically active coloured textile platform with simultaneous UV protection properties. Two approaches were developed: classical, which included dyeing of the cotton samples with Curcuma longa (turmeric) extracts at different concentrations (5 g/L, 10 g/L and 15 g/L) and subsequent hydrothermal in-situ synthesis of TiO2 in the presence of the dyed cotton samples, and greener, in which simultaneous dyeing with turmeric extracts and hydrothermal in-situ synthesis of TiO2 were carried out. Since increasing the turmeric concentration hindered the photocatalytic performance of TiO2 in the chemically modified cotton samples, 5 g/L was selected as the most suitable turmeric concentration. A comparison of the chemical modification processes shows that the simultaneous dyeing of cotton with turmeric extract and hydrothermal in-situ synthesis of TiO2 was beneficial and resulted in a UV protection factor 50+, which corresponds to excellent protection category. The photocatalytic activity of TiO2 was maintained in the presence of turmeric, indicating the compatibility of both players in the chemically modified cotton, but not the creation of a turmeric–TiO2 heterojunction with visible-light-driven photocatalysis. The presence of TiO2 inhibited the photodegradation of the curcumin dye, further confirming the compatibility of the two players.

Giant goldenrod (S. gigantea Aiton) is considered an invasive weed in Europe, Asia, Australia, and New Zealand. In this research, the untreated and chitosan-treated cotton fabrics were functionalized with goldenrod inflorescences aqueous extract, at room temperature and 95°C. Zeta potential of fabrics was determined as a function of pH and the results showed an increased isoelectric point from 2.50 to 5.25 and amphoteric character of the chitosan-treated sample. The antioxidant activity (AA) of extract and functionalized fabrics was determined using DPPH analysis, while color and ultraviolet protection factor (UPF) were determined spectroscopically before and after wash and lightfastness testing. The chitosan pretreatment and dyeing of cotton at higher temperature increased AA (from 41.19 ± 0.28 to 56.08 ± 0.25), UPF (from 33.05 to 51.59) and color strength (K/S) (from 1.74 to 2.21), providing dyed cotton with excellent UV protection and a free radical inhibition activity. The samples had good wash fastness in terms of color (ΔEab* < 1), but not in terms of UV protection (UPF value decreased after washing to 23.47). The overall lightfastness was good to excellent (the UPF values of chitosan and dyed samples did not change much after lightfastness test (UPF = 51.75).

The use of nanomaterials to functionalise textiles offers new opportunities for chemical modification of textile fibres’ surfaces to achieve multifunctional protective properties. In this study, novel coatings were tailored on cotton fabric by embedding a mixture of TiO2 and ZnO nanoparticles (NPs) of different molar ratios into a chitosan polymer matrix. The excitation energies of the TiO2+ZnO composites generated in the coatings ranged from 3.20 eV to 3.25 eV, indicating that the photocatalytic performance of the functionalised cotton was driven by UV light. The presence of TiO2+ZnO composites increased the UV protection factor (UPF) of the cotton fabric from 4.2 for the untreated sample to 15–21 for the functionalised samples. The UPF values of the coatings slightly decreased after repeated washing. The ZnO in the TiO2+ZnO composites conferred biocidal activity to the coatings, which were resistant to washing at higher ZnO concentrations. In addition, the TiO2 in the TiO2+ZnO composites was responsible for the enhanced photocatalytic self-cleaning of the functionalised cotton, which was observed during the initial period of illumination at lower ZnO concentrations in the composite. The main advantage of these TiO2+ZnO composite coatings is their multifunctionality, which cannot be provided by single-component TiO2 or ZnO coatings. Moreover, these coatings have wide-ranging practical applications, as they were composed of commercially available nanomaterials and were applied using conventional pad–dry–cure equipment.

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 development of durable multifunctional properties is crucial for the production of high-performance technical textiles. In this work, a novel, environmentally friendly and facile method was developed for the chemical modification of cotton fabric by in situ biosynthesis of Ag NPs in the presence of sumac leaf extract as a reducing agent on TiO2, ZnO and TiO2 + ZnO previously applied to cotton fibres. The results showed that the presence of TiO2, ZnO and TiO2 + ZnO significantly increased the concentrations of the synthesised Ag NPs on the cotton fibres compared to the one-component Ag coating. This resulted in excellent antimicrobial properties of the TiO2/Ag, ZnO/Ag and TiO2 + ZnO/Ag composites even after 25 washes. While the TiO2 and ZnO particles in the composite were incompatible, the synergistic effect among Ag, TiO2 and ZnO in the composites resulted in excellent UV blocking properties of the coatings before and after 25 washes. Since the biosynthesis of Ag NPs was accompanied by a yellow–brown colouration of the samples, the photocatalytic self-cleaning of the composite coating could not be determined from the photodegradation rate of the coffee stains. This research provides a new environmentally friendly approach to producing durable antimicrobial and UV blocking coatings on cotton fibres.

The aim of this research was to investigate different parameters of the in situ synthesis of ZnO nanoparticles on cotton in order to achieve a high ultraviolet protection factor (UPF). In the fi rst part of the research the influence of different reducing agents (Na2CO3, KOH, and NaOH) and their molar concentrations (0.1 M and 1 M) on the formation of ZnO nanoparticles and on the UPF values of cotton fabric were studied. The second part of the research was focused on the other parameters of in situ synthesis, such as the synthesis time ratio (time ratio between the treatment of the fabric in the precursor (ZnCl2) and treatment after the reducing agent was added) and drying period duration after the in situ synthesis. Using UV/Vis spectroscopy, high UPF values (UPF 50+) were measured for cotton fabrics where in situ synthesis was performed using NaOH and KOH, both at 1 M molar concentration. Inductively coupled plasma mass spectrometry (ICP-MS) revealed a higher content of zinc on the fabric when NaOH was used. Scanning electron microscopy (SEM) showed that use of this reducing agent resulted in cotton fabric completely covered with small, round shaped nanoparticles. From the second part of the research, it was found that longer treatment times after the reducing agent was added produced functionalised cotton fabric with higher UPF values. The drying period duration after in situ synthesis did not signifi cantly affect the UPF value of the fabric, but it did influence the morphology of the synthesised nanoparticles. With a longer drying time the nanoparticles were more rounded. The samples had poor wash fastness even after the fi rst wash, which was found through low UPF values.

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.

An overview of recent work on the low-temperature plasma-assisted synthesis of zinc oxide (ZnO) nanoparticles is presented and interpreted in terms of gas-phase and surface reactions with illustrated examples. The thermodynamical nonequilibrium conditions allow the formation of chemically reactive species with a potential energy of several eV, which readily interact with the Zn precursors and initiate reactions leading to the formation of nanoparticles or nanowires. The high-quality nanowires were synthesized from Zn powders only upon interaction with moderately ionized plasma in a narrow range of plasma parameters. This technique is promising for the synthesis of large quantities of nanowires with aspect ratios well above 10, but the exact range of parameters remains to be determined. Apart from the ex situ techniques, the ZnO nanoparticles can be synthesized by depositing a film of precursors (often Zn salts or Zn-containing organometallic compounds) and exposing them to oxygen plasma. This technique is useful for the synthesis of well-adherent ZnO nanoparticles on heat-sensitive objects but requires further scientific validation as it often leads to the formation of a semicontinuous ZnO film rather than nanoparticles. Both low-pressure and atmospheric plasmas are useful in converting the precursor film into ZnO nanoparticles despite completely different mechanisms.

In this paper was examined the influence of mordant usage in dyeing of knitted fabrics with plant extracts, with or without plasma pretreatment, on its degree of coloration. Three different fabrics were used (100% cotton, 100% bamboo and 50% cotton/50% bamboo) with same constructional characteristics and roughly with the same surface mass. Knitted fabrics were treated with aqueous plant extract of Achillea millefolium L., by using bath exhaustion method, and with or without 3% KNaC4H4O6 · 4H2O. The degree of coloration of differently treated knitted fabrics was evaluated with CIELAB method and with stereomicroscope. Antimicrobial properties of knitted fabrics with plant extract of Achillea millefolium L. were tested on Escherichia coli, Staphylococcus aureus and Candida albicans by using parallel streaking method (AATCC TM 147). It was found that the dyeing of knitted fabrics with aqueous extract of the plant Achillea millefolium L. with addition of KNaC4H4O6 · 4H2O caused an incensement of the color fastness after washing compared to knitted fabric dyed without addition of KNaC4H4O6 · 4H2O. It was also found that the processing with plant extract had a positive impact on Escherichia coli, bacteria known as resistant, but only for knitted fabrics after washing.

V tomto příspěvku byl sledován vliv plazmové přípravy na strukturu a antimikrobiální vlastnosti pletenin (100% bavlna, 100% bambus a 50% bavlna / 50% bambusu) ošetřených alkoholickými bylinnými výtažky z řebříčku obecného a křídlatky japonské. Vliv plazmové přípravy na bázi vodní páry na povrchovou funkčnost nebo na změny struktury pletenin se hodnotí pomocí SEM. Antimikrobiální vlastnosti pletenin ošetřených bylinnými extrakty byly testovány na Escherichia coli, Staphylococcus aureus a Candida albicans za pomoci paralelní pruhovací metody (AATCC TM 147 - 2004). Stupeň zabarvení byl hodnocen metodou CIELAB a stereomikroskopem. Bylo zjištěno, že plazmová příprava a zpracování za použití bylinného výtažku z křídlatky japonské mělo pozitivní dopad na antimikrobiální ochranu pletenin proti Staphylococcus aureus.

Samples of bleached cellulose fabric were treated with weakly ionized highly dissociated oxygen plasma in order to improve the binding of ZnO nanoparticles, antibacterial properties and biodegradability. Low specific discharge power of about 24 W l−1 was applied in order to minimize thermal effects following plasma treatment. Optical emission spectroscopy revealed weak etching of the fabric while x-ray photoelectron spectroscopy showed formation of oxygen-rich functional groups. Scanning electron microscopy revealed an improved uptake of ZnO nanoparticles and the standard transfer method highlighted excellent antimicrobial effects for Staphylococcus aureus and Escherichia coli. The biodegradability of all samples was determined using the standard ISO test and revealed excellent results for plasma-treated samples even in cases when they were functionalized using ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

Some applications of extremely non-equilibrium oxygen plasma for tailoring the surface properties of organic as well as inorganic materials are presented. Plasma of low or moderate ionization fraction and very high dissociation fraction is created by high frequency electrodeless discharges created in chambers made from a material of low recombination coefficient. The O atom density often exceeds 1021 m−3 which allows for rapid functionalization of carbon-containing materials. Surface saturation with polar oxygen-rich groups is achieved in a fraction of a second and further exposure leads to etching. The etching is often non-uniform and results in nano-structuring of surface morphology. A combination of rich morphology and saturation with polar functional groups allows for a super-hydrophilic character of originally hydrophobic materials. Polymer composites are etched selectively so the polymer component is removed from the sample surface, leading to modified surface properties. Furthermore, such a treatment allows for distinguishing the distribution and orientation of fillers inside the polymer matrix. The exposure of inorganic materials to non-equilibrium oxygen plasma causes one-dimensional growth of metal oxide nanoparticles, thus representing a unique technique for the rapid catalyser-free growth of nanowires. [ABSTRACT FROM AUTHOR]