Nanodiamond-decorated thin film composite membranes with antifouling and antibacterial properties

Abstract

Membrane fouling is the main bottleneck that restricts the practical applications of membrane processes. In this work, we report an effective and scalable method to reduce the fouling of polyamide thin film composite (TFC) membranes by grafting amine-functionalized nanodiamond (ND) particles. The surface chemistry of ND was modified to improve the compatibility of nanoparticles with the polyamide membranes. Fouling experiments with sodium alginate (SA) and bovine serum albumin (BSA) showed that the ND layer substantially reduced fouling of the membranes. The flux of the ND-modified membrane made with a solution containing 1000 ppm ND particles declined only by 15% (SA) and 9% (BSA) after 180 min of filtration, while the flux of the pristine TFC membrane declined by 42% (SA) and 21% (BSA). The ND particles increased the antibacterial activity of the membranes, increasing the inactivation and mortality rate of Escherichia coli (E. coli) bacteria cells. Because they are easy to make and have antifouling and antibacterial properties, these membranes can be applied in a broad range of forward osmosis water reclamation applications.