Long-Lasting Photocatalytic and Antimicrobial Activity of Cotton Dishcloths Finished with TiO2 Nanoparticles and Zinc Pyrithione

This study assesses the durability of self-cleaning and antimicrobial activities of dishcloths made of 100% cotton woven fabric modified with TiO2 nanoparticles (NPs) and zinc pyrithione particles (ZnPt). The self-cleaning properties were measured as the ability to decompose staining particles via photocatalytic action under UV/VIS light irradiation and confirmed by colour measurements (K/S values, colour differences, and colour changes ΔL*, Δa*, Δb*). The SEM micrographs confirmed the long-term durability of the modification process, and ICP-OES analysis confirmed the presence of Ti and Zn elements on and within the fabric. The amounts of TiO2 and ZnPt decreased by 2.2–2.5 times after the first 5 washings and by 2.1–1.2 times after the subsequent 45 washings. Antimicrobial activity was tested against Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 11229 and Candida albicans ATCC 10231. The results indicate that the material maintains excellent self-cleaning properties and good antimicrobial activity for up to 50 washings; however, activity against E. coli remains weak after 30 and 50 washings.