Polymer network strengthened filter paper for durable water disinfection

Abstract

Filter-paper-based water disinfection materials have attracted considerable attention nowadays for their cost-saving and convenience in practical applications. Nevertheless, the poor durability and leakage of the embedded antibacterial agents still exist during water purification processes. In this study, a filter-paper-based water disinfectant was fabricated by combining a tannic acid (TA) cross-linked gelatin (GEL) polymer network with an oxidized cellulose filter paper (OFP) through Schiff base linkages. The resulted OFP-GEL-TA filter paper showed enhanced tensile strength under wet conditions of 7.3-fold compared with the unmodified filter paper. And it maintained the high tensile strength after soaking in water for at least 36 h, indicating excellent durability of the OFP-GEL-TA. Moreover, as a biocompatible natural antibacterial agent, the cross-linker TA endowed the prepared OFP-GEL-TA with favorable antibacterial property. When infected water was filtered through OFP-GEL-TA, the bacterial killing efficiency was as high as 99 % after examining the filtrate via colony counting assay, and it still higher than 98 % after five repeated use. In addition, the quite slowly release behavior of TA further entitled the OFP-GEL-TA with persistent bactericidal efficiency. Taken together, these properties make OFP-GEL-TA a promising candidate as an economical, biocompatible and durable water disinfectant for drinking water purification.