The fabrication of thin-film nanocomposite membrane for organic solvent forward osmosis via host-guest chemistry of α-cyclodextrin

Organic solvent forward osmosis (OSFO) is a newly developing technology for recovering the organic solvent and concentrating substances. The commercial polyethylene (PE) battery separator is the ideal support for OSFO owing to the low structural parameter, resistance for organic solvents, commercially available and simple preparation process. A novel thin-film nanocomposite (TFN) membrane for OSFO was fabricated on the dopamine (DA)-modified PE support by adding alpha-cyclodextrin (alpha-CD) in the polyamide (PA) layer. The inclusion complexes (MPD@alpha-CD) formed by host-guest chemistry enhanced the stability of the membrane. Because of the Janus path and molecular sieving effect of alpha-CD, the TFN membrane exhibited superior permeability and selectivity among the recent reports. Moreover, the TFN membrane showed high rejection of Rhodamine B and Oxytetracycline, so it had great potential for solutes concentration. Herein, this work broadens the application of eco-friendly alpha-CD in membrane field and improves the PE composite membrane for OSFO process.