Facilely cyclization-modified PAN nanofiber substrate of thin film composite membrane for ultrafast polar solvent separation

Membranes with high permeance, excellent selectivity coupled with adequate solvent resistance are required for organic solvent nanofiltration (OSN) applications. But the trade-off relationship between the solvent resistance and permeance remains a critical challenge for polymeric-based thin film composite (TFC) membranes with necessary chemical crosslinking. Herein, a novel facile cyclization modification of polyacrylonitrile (PAN) nanofiber substrate is proposed by a simply thermal treatment and subsequent alkaline hydrolysis, and employed for the fabrication of TFC-OSN membrane for the first time in strong polar aprotic solvent systems. The reaction mechanism involved, solvent resistance and pore structure of PAN nanofiber substrate brought by the modification are investigated. TFC-OSN membrane supported by the modified PAN nanofiber substrate exhibits ultrahigh solvent permeance up to 13.3 L m(-2) h(-1) bar(-1) coupled with a 99.7% rejection in rose bengal/DMF system and a good long-term stability. This study is therefore believed to provide useful guidelines for the development of next-generation OSN membranes.

Automated summary

A novel facile cyclization modification of PAN nanofiber substrate was proposed for the fabrication of TFC-OSN membrane, demonstrating high solvent permeance and resistance. The modified PAN nanofiber substrate supported TFC-OSN membrane exhibits potential industrial applications with good permeance and resistance in organic solvent systems.