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In this study, a novel green process was developed to produce a multifunctional cotton (CO) fabric incorporating TiO2/curcumin composites that simultaneously provides UV protection and photocatalytic performance. For this purpose, TiO2 was synthesised using the sol–gel process; loaded with the natural colourant curcumin as a visible light absorber at two temperatures, i.e., 70 and 350 °C; and applied to the CO fabric via the pad–dry–cure process. For comparison, TiO2 was synthesised without curcumin under the same conditions. The synthesis conditions at 70 °C ensured the formation of predominantly amorphous TiO2, while curcumin promoted TiO2 crystallisation despite the low synthesis temperature. A 350 °C synthesis temperature was high enough to form the polymorphic TiO2 anatase phase. Although the increase in synthesis temperature and the presence of curcumin in the composites caused a bathochromic shift in light absorption, the photocatalytic activity of all samples was mainly driven by UV light. Chemically modifying the CO fabric significantly reduced the light transmittance of the samples, with the highest absorption of UV light obtained for the sample containing the TiO2/curcumin composite synthesised at 70 °C. This sample provided excellent UV protection with a UPF value of 51.6. All chemically modified CO samples showed photocatalytic activity, degrading coffee stains and decolourising methylene blue and Rhodamine B dye solutions. The highest photocatalytic efficiency and recyclability were obtained again for the CO sample with the TiO2/curcumin composite synthesised at 70 °C, demonstrating the synergistic effect between TiO2 and curcumin in the composite prepared under these synthesis conditions.

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.

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.