Fabrication of antibacterial silver nanoparticle-loaded PVA/chitosan microfibers via forcespinning for wastewater disinfection

Abstract

Water pollution has become a serious environmental problem in many countries of Southeast Asia, affecting both civil and industrial wastewater. Various research approaches have been employed to purify wastewater, such as using absorbent membranes for heavy metal ions and dyes as well as disinfection using antimicrobial agents. This study aims to fabricate antibacterial polyvinyl alcohol/chitosan (PVA/CS) microfibers containing silver nanoparticles (Ag-NPs) using the forcespinning method. The results of our systematic investigation indicate that experimental factors such as PVA/CS concentration, microfiber injection needle size, and spin speed directly determine the morphology of the fabricated microfibers. The PVA/CS fibers were fabricated with uniform diameters and well-separated silver nanoparticles. The average diameter was estimated to be around (1.74 ± 0.13) µm at a PVA concentration of 13 wt% in a 50% acetic acid solution, with an inner needle diameter of 0.81 mm and a rotational speed of 15 000 rpm. The antibacterial performance was evaluated following the Vietnamese standard TCVN 6187-2:1996 (ISO 9308-2:1990), targeting Escherichia coli and coliform bacteria in polluted water. We found that the PVA/CS microfibers loaded with Ag-NPs achieved an antibacterial efficiency of 90%. This strongly hints that PVA/CS microfibers loaded with Ag-NPs can potentially be used as water disinfectants. The outcome of this work implies that PVA/CS microfiber membranes containing AgNPs could be a novel filtering material for wastewater disinfection and could be widely used to purify water for improved public health.