Design of high-performance biomimetic reverse osmosis membranes by introducing loose liposome as an artificial water channel

Superior permeability and high selectivity are crucial performances criterion for reverse osmosis (RO) membranes. Inspired by aquaporin-based biomimetic membranes, the loose liposomes as artificial water channels were prepared by thin-layer hydration method with lyso-phospholipids (C14lyso) and cholesterol followed by incorporating liposomes into the polyamide selective layer via in situ interfacial polymerization to fabricate liposomes-based RO membranes (TFC-C14lyso). Stopped-flow tests verified that C14lyso liposomes possess fast water transportability and the effect of C14lyso liposomes on the intrinsic structure of the polyamide selective layer was comprehensively explored. Meanwhile, the structure and performance of the TFC-C14lyso membranes could be regulated by varying the liposome concentrations. As a result, TFC-C14lyso-2 (the concentration of C14lyso liposomes is 0.25 mg/mL) presented an optimal separation performance, showing high water permeance of 3.80 L m−2h−1 bar−1 and NaCl rejection of 98.6 %. Moreover, the separation mechanism regarding the enhanced permeability of TFC-C14lyso-2 was profoundly revealed via the structure and performance comparison with TFC-DOPC fabricated by incorporating dense DOPC liposomes into its PA selective layer. Building on these studies, our work may provide a facile and versatile pathway for designing advanced membranes in desalination.