Intercalated 2D nanowires network cooperating with its entanglement in tuneable GO membrane nanochannels for ultrafast organic solvent nanofiltration

Abstract

Organic solvent nanofiltration (OSN) as an emerging membrane separation technology has received substantial attentions recently. However, high permeability and selectivity simultaneously remains a momentous challenge for OSN mainly limited by the trade-off between permeance and selectivity. Here, ultralong and flexible polymeric nanowires (PWs) with positive charge were used to construct highly entangled PWs network fabricating interlayered GO composite membrane for OSN. The membrane exhibits a unique configuration with alternating stacking of highly entangled nanowires network and ultrathin GO layers. Meanwhile, the alternating layers become interlinked closely due to the strong electrostatic interactions between the positively charged nanowires and negatively GO layers. It could endow composite membrane with excellent stability in solvent. Unique membrane separation channels, constructed by close-knit interlaced PWs network and GO interlayer structure, allow a high flux of various solvents through the membrane and excellent rejection for small molecules. Solvent permeance of the optimized membrane could reach 91.3 L/m2·h with rejection of above 90% for Congo Red in methanol. The designed GO composite membrane is promising to practical application in OSN field, and it may also be useful for aqueous applications in separation and precise screening process.