Water Purification Filter Prepared by Layer-by-layer Assembly of Paper Filter and Polypropylene-polyethylene Woven Fabrics Decorated with Silver Nanoparticles

Cellulose-based water filters are an affordable alternative to remove particulate matter; however, bacteria are too small to be removed simply through size exclusion. Cellulose-based water filters prepared by layer-by-layer (LBL) assembly with polypropylene-polyethylene (PP/PE) fabric decorated with silver nanoparticles (AgNPs) were tested to remove bacteria from water samples. The gallic acid reduction method was used to produce potent antibacterial AgNPs; their decoration onto PP/PE woven fabrics and the preparation of five-layered paper filters were further investigated. The use of acidic conditions for loading AgNPs and improving their spatial distribution onto the PP/PE fabrics, as revealed by scanning electron microscopy, was found to be correlated with the fabrics’ antibacterial activity. The PP/PE fabrics decorated with a higher density of AgNPs (at pH 2) showed 96.7 % and 97.9 % reductions in the growth of E. coli and S. aureus, respectively. Similarly, paper filters fabricated by LBL assembly of AgNP@PP/PE fabrics with cellulose filters deactivated growing E. coli and S. aureus bacteria with good efficiency: approximately 99.4 % and 98.7 %, respectively. The results indicate that fabricating water purification filters from the cellulose-based paper is feasible with LBL type assembly. The assembled paper filters could be commercialized for point-of-use water purification in the future to prevent the spread of water-borne diseases.