Teflon AF2400/polyethylene membranes for organic solvent nanofiltration (OSN)

We have successfully developed novel Teflon AF2400/polyethylene (PE) membranes for organic solvent nanofiltration (OSN) by depositing an ultra-thin Teflon AF2400 membrane on top of a commercially available PE porous support. By adjusting the coating concentration and the relative humidity (RH) of drying air, a Teflon AF2400 layer of ~100 nm was deposited on the PE support. The newly developed membrane has a very low MWCO of ~150 g/mol and shows high pure solvent permeances of 3–8 L/m2-h-bar for ethyl acetate, toluene and hexane. In addition, the membrane displays stable separation performance over 2 weeks for the separation of acetone/rose Bengal and possesses a rejection of ~99.5% to triglycerides using 20 wt% oil/solvent feeds in both oil/acetone and oil/hexane solutions. Since the fabrication of Teflon/PE membranes does not involve in cross-linking or pore preserving agents, this study may provide a new and greatly simplified strategy to design next-generation OSN membranes.