Atomic layer deposition (ALD) is a versatile technique to functionalize textile substrates due to its ability to create conformal films on the fibers’ surface. Photocatalytic activity and antibacterial activity of TiO2 and ZnO films deposited onto polyamide 66 fabrics were investigated. ALD coated fabrics were examined to eliminate Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria with ISO 20645 and AATCC 100 standard methods. Both materials were only slightly successful for the elimination of E. coli. However, ZnO films were more effective in killing S. aureus bacteria than TiO2 films independent of incubation conditions (i.e., under dark or ambient light). Deposited films were characterized using SEM, FTIR, UV-Vis, and XPS spectroscopy techniques. Furthermore, the samples’ photocatalytic activity was determined by measuring methylene blue degradation as a model organic molecule showing that ZnO films were better photocatalysts as deposited. The films’ antibacterial mechanism is mainly due to ions dissolving from the films into the bacterial solutions.

Cotton fiber consumption is higher than any other natural fiber due to its superior mechanical and physical properties. In the conventional reactive dyeing process, the dye undergoes hydrolysis due to hydrogen bonding and weak Van der Waals forces, yielding poor washing color fastness. Additionally, the post-dyeing wash-off process consumes significant amounts of water, energy, and time in order to remove the unreacted and hydrolyzed dye. Therefore, reactive dyes are predominantly utilized to color cotton fabrics as the covalent bond formed between dye and fiber results in excellent washing fastness for a wide range of colors, and improved ease of use. To support more efficient, economical, and sustainable reactive dyeing, polymers can be used as effective dye transfer inhibitors (DTIs) in the reactive wash-off process. In this study, poly(vinylpyrrolidone) (PVP) homopolymer and poly(vinylpyrrolidone)-co-poly(vinylimidazole) (PVP-co-PVI) were synthesized at different molecular weights. These polymers were then employed as DTIs to evaluate their performance during the wash-off process for dyed cotton fabrics treated with three reactive dyes (Reactive Red 195, Reactive Blue 221, and Reactive Yellow 145). It is noteworthy to mention that the alternative wash-off procedure involved only three stages, in contrast to the series of washing steps necessary in the conventional method. Evaluation of the DTIs was focused on parameters such as color strength, washing fastness, chemical oxygen demand (COD), as well as energy, water, and time consumption. The findings revealed that while the polymer DTIs generated minor differences in dyed fabric colors in comparison to conventional dyeing, they significantly improved washing fastness. The polymer DTIs studied display excellent potential to provide a much more sustainable dyeing process by saving 90% energy, 40% water, and 50% time versus conventional wash-off processing. The wastewater COD values from the polymer-assisted reactive dye wash-off process were higher for all reactive dyes tested than those from conventional processing. While the higher COD values are attributed to the lower water volumes, this finding highlights the need for further studies. In summary, PVP polymers successfully served as DTIs in the reactive dyeing washing-off process, providing massive water-energy-time efficiency improvements and, subsequently, a more sustainable process for cotton fabric dyeing.