Ultrafast organic solvent nanofiltration in C-C bonded conjugated microporous membrane-based nanochannels by space-confined polymerization

Organic solvent nanofiltration is a new membrane technology for separation of organic solvents with low energy consumption and environmental compatibility. However, commercial ultrafiltration membranes are unsuitable for organic solvents separation owing to their low retention and poor solvent resistance. C-C bonded conjugated microporous polymer (CCMP) membranes consisting of all-rigid conjugated systems feature well-developed microporosity and excellent organic resistance. Herein, we report a strategy to prepare solvent-resistant CCMP@PTFE composite membrane by portioning channels in polytetrafluoroethylene (PTFE) ultrafiltration membrane by space-confined polymerization. Owing to intrinsic micropores from crosslinking of multifunctional rigid building units and the robustness of PTFE substrate, three CCMP@PTFE membranes exhibit outstanding separation performance, solvent resistance and high flexibility, which rival against the best of those reported membranes. This strategy inspires the design of OSN membranes with high performance.

Automated summary

Organic solvent nanofiltration (OSN) is a low energy consumption and environmentally-friendly membrane technology. However, current commercial ultrafiltration membranes are not suitable for OSN due to their low retention and poor solvent resistance. In this study, a solvent-resistant CCMP@PTFE composite membrane was prepared by incorporating CCMP into PTFE ultrafiltration membrane through space-confined polymerization. The resulting CCMP@PTFE membranes exhibit excellent separation performance, solvent resistance, and flexibility, rivaling the best reported membranes. This strategy provides inspiration for the design of high-performance OSN membranes.