Surface engineering design of polyamide membranes for enhanced boron removal in seawater desalination

Tailoring excellent polyamide (PA) seawater reverse osmosis (SWRO) membranes for boron (B) removal is a key challenge. Herein, we developed a facile surface engineering design strategy to improve the boron removal and desalination performance of SWRO membranes by controlling the reaction kinetics of interfacial polymerization. The functional groups and density of the oligomers covering the surface of PA skeleton were tuned to reduce the pore size and hydrogen bonds interaction inside the PA active layer with an enhanced the selectivity of the membranes. The designed membrane exhibits a high boron removal rate of 95.34%, while displaying a NaCl rejection of 99.8% and an acceptable water flux. This work offered a basic framework for the design of outstanding SWRO membranes, and also provided some insights for the formation and structure-property relations of polyamide membranes based on interfacial polymerization.