Sol-gel technology for greener and more sustainable antimicrobial textiles that use silica matrices with C, and Ag and ZnO as biocides

Abstract

Based on the philosophy of Green Chemistry, in order to grant antimicrobial properties to fabrics, in this work a 100% cotton fabric was used impregnating silver (Ag) and zinc oxide (ZnO) with the addition of carbon extracted from disused batteries, in the intuition of reuse them in a conscious and relevant way. For this, a simple and greener chemical route that occurs at low temperatures was used, the silica-based sol-gel method, which requires a precursor, in this case, tetraethyl orthosilicate (TEOS), and a catalyst to generate the basic hydrolysis using ammonium hydroxide. To evaluate the durability of the coating on the fabric, it was subjected to several wash cycles. Finally, its antimicrobial activity against fungal and bacterial strains was evaluated by the modified standard method (DIN 53931) and the agar-based diffusion method (SN 195920–1992), respectively. The sol-gel green method was effective for obtaining coating for the inhibition of fungal and bacterial strains. In addition, there was a high degree of persistence of the additives after the washing cycles before the antimicrobial tests, registering inhibition up to 20 cycles, making not only the process but also the final alternative fabric greener and more sustainable.