In situ photoreduction of Ag+-ions on the surface of titania nanotubes deposited on cotton and cotton/PET fabrics

This study discusses the possibility of in situ photoreduction of Ag+-ions on the surface of titania nanotubes (TNTs) deposited on the cotton and cotton/PET fabrics in the presence of amino acid alanine and methyl alcohol. TNTs were synthetized by hydrothermal method. The proposed interaction between titania, alanine and Ag+-ions was based on the results obtained by FTIR measurements. In order to enhance the binding efficiency between TNTs and fibers, the fabrics were previously impregnated with polyethyleneimine. The presence of TNT/Ag nanocrystals on the surface of fibers was proved by SEM, AAS, XRD and XPS. Larger amount of silver was detected on the cotton fabric. Fabricated TiO2/Ag nanocrystals provided maximum reduction of bacteria E. coli which was preserved after five washing cycles despite significant release of silver. The perspiration fastness tests indicated that silver release did not depend on pH. The presence of TNT/Ag nanocrystals imparted maximum UV protection to fabrics

In situ synthesis of Cu/Cu2O nanoparticles on the TEMPO oxidized cotton fabrics

In situ synthesis of Cu/Cu2O nanoparticles on the cotton fabric discussed in this study relies on adsorption of Cu2+-ions by carboxylate groups generated through the TEMPO-mediated oxidation of cellulose and their subsequent reduction by sodium borohydride. In order to establish the influence of aldehyde and carboxylate groups on the nanoparticles formation, the duration of TEMPO-mediated oxidation was varied. Chemical changes induced by TEMPO-mediated oxidation were evaluated by titrimetric determination of the amounts of aldehyde and carboxylic groups in cotton and FTIR spectroscopy. The presence of Cu/Cu2O nanoparticles on the cotton fabric was confirmed by FE-SEM, AAS and XRD analyses. Antimicrobial activity of synthesized nanoparticles was tested against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and fungi C. albicans. The extension of TEMPO oxidation time led to an increase of carboxylate group content and consequently, formation of larger amounts of Cu/Cu2O nanoparticles. All fabricated textile nanocomposites provided excellent antibacterial and acceptable antifungal activity. They also ensured a controlled release of Cu2+-ions in physiological solution which is an imperative for infection prevention