Ferroelectric membrane for water purification with arsenic as model pollutant

Membrane filtration is widely applied, but often subject to a trade-off between permeability and selectivity , an inherent challenge in membrane processes. Charged membranes are a promising alternative to address this challenge. Here, ferroelectric BaTiO 3 nanoparticles , with a spontaneous electric polarization, were assembled into the traditional polyamide nanofiltration membranes by interfacial polymerization then charged by corona poling. Importantly, charges of ferroelectric BaTiO 3 nanoparticles sealed in polymers were hardly affected by ambient aqueous environment. The polarized ferroelectric membrane (TFN-mBTO-E) showed higher permeability (2.4 and 1.5 times) and favorable rejection ratio about 97% for arsenic removal, a strictly controlled contaminant, compared with common membranes and unpolarized TFN-mBTO membranes, due to strong hydrophilicity and increased surface potential derived from ferroelectric charges. Thereby, it could provide new insight into charged membrane, laying a foundation for the application of ferroelectric materials in membrane filtration.