Tea Polyphenol-Coated ZIF-8 Blends Polyethersulfone for Modulating Water Flux and Antibacterial Properties of Ultrafiltration Membrane

Abstract

ZIF-8 have been extensively studied in water treatment membranes, and they exhibit excellent modification effects in the membranes. In this study, tea polyphenol-coated ZIF-8 nanoparticles are synthesized via one-pot synthesis and then are blended to modify polyethersulfone ultrafiltration membrane. The shape of the nanoparticles is affected by changing the content of tea polyphenol. Different nanoparticles blends polyethersulfone for ultrafiltration membranes. It is found that adding ZIF-8@Tea polyphenol with hydrophilic properties could significantly improve wettability of membrane; when 0.3 g of ZIF-8@Tea polyphenol is added, the film contact angle decreases to 27.3 ° and shows an excellent rejection rate for methylene blue, methyl orange, and Congo red. The addition of ZIF-8 significantly enhances the retention rate of bovine serum albumin by water treatment membranes, which is mainly attributed to its precise size sieving effect. The accumulation or growth of ZIF-8 particles creates more uniform nanoscale channels, ultimately reducing the average and maximum pore diameters. The effective separation layer of membranes make much smaller than the size of bovine serum albumin. The strategy not only enables the ultrafiltration membrane to maintain high water flux under different pressures but also endows it with the ability to resist Escherichia coli microorganisms.