Teflon AF2400/Polyethylene organic solvent nanofiltration membranes

Abstract

We have successfully developed Teflon AF2400/polyethylene (PE) OSN membranes by depositing ultra-thin Teflon AF2400 membranes on a commercially available PE support through coating Teflon solutions on the support. By adjusting the coating concentration and the relative humidity of drying air, a ~100 nm Teflon AF2400 layer is deposited on the PE support. The newly developed membrane has high permeances of 3~8 L/m2-h-bar for ethyl acetate, toluene and hexane. Furthermore, the membrane has a very low MWCO of ~150 g/mol. In addition, the membrane shows stable separation performance over 2 weeks for the separation of acetone/rose bengal. Lastly, the membrane is demonstrated to be promising for the separation of oil/acetone and oil/hexane with ~99.5% rejection of triglycerides using 20 wt% oil/solvent feeds. With no cross-linking or pore preserving agents for the Teflon/PE membranes, the fabrication process of the membranes is greatly simplified.