Polyamide filled crosslinked polyaryletherketone composite membrane with high stability for organic solvent nanofiltration

Organic solvent nanofiltration (OSN) is a green, efficient and energy-saving new separation technology. However, it is exigent to membrane materials with both good soluble processability and solvent resistance, as well as methods for preparing composite membranes that combine high accuracy and stability. In this work, a novel polyaryletherketone containing phenylamine structure (PEK-PA) was prepared and used to fabricate a novel solvent resistant composite membrane via strategies of chemical crosslinking and polymer filling into the surface pores of the membrane. The crosslinking between PEK-PA and trimesoyl chloride improves the solvent resistance of the membrane and the strategy of polyamide filling improves the separation accuracy of the membrane. The prepared OSN membranes exhibit exceptional separation accuracy, with a molecular weight cut-off within the range of 214 g mol- 1 to 383 g mol- 1. More importantly, the prepared membranes exhibit higher stability than the thin-film-composite membranes prepared by interfacial polymerization, which was demonstrated by a designed reverse pressure experiment. The prepared membranes can be continuously operated in DMF for 60 h, thereby demonstrating their excellent stability even for harsh polar aprotic solvents. Therefore, this work presents a novel solvent resistant membrane material with potential applications for OSN.