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

The influence of corona treatment and impregnation with colloidal TiO2 nanoparticles on biodegradability of cotton fabric

This study discusses the effect of corona pre-treatment at atmospheric pressure and subsequent loading of colloidal TiO2 nanoparticles on the biodegradation behavior of cotton fabric. Biodegradation performance of the control and finished samples was evaluated by standard soil burial tests in predetermined periods of 3, 9 and 18 days. Color and breaking strength measurements were utilized for assessment of biodegradation progress. Morphological and chemical changes induced by biodegradation were analysed by SEM and FT-IR analyses, respectively. Colorimetric, morphological and chemical changes induced by the biodegradation process were slightly less prominent on corona pre-treated cotton fabric impregnated with TiO2 nanoparticles compared to corona treated and control cotton fabric. Although the breaking strength of all samples significantly decreased after 18 days of soil burial, this decline was the least evident on the sample impregnated with TiO2 nanoparticles. However, taking into account the extent of these differences, the influence of TiO2 nanoparticles on biodegradation rate of cotton fabric, which underwent a combined treatment corona/impregnation with TiO2 nanoparticles, could be considered as insignificant. These results confirm that chemical modification of cotton fabrics with plasma and subsequent loading of TiO2 still maintained sustainability of cellulose fibres