Biomimetic Channel Construction and Interfacial Hydrogen-Bond Engineering for Advanced Separation Membranes

Abstract

Conventional membranes suffer from a trade-off between permeability and selectivity. To address this issue, a biomimetic membrane (HEI-PA-SO3H) was fabricated through the optimization of channel geometry and interfacial hydrogen-bond networks in this study. Specifically, sulfonic acid groups (-SO3H) were introduced at the interface of the polyamide (PA) layer to regulate the hydrogen-bond network, while self-assembled hexyl-ureido-ethyl imidazole (HEI-quartet) was embedded to construct ordered biomimetic water channels. The optimized HEI-PA-SO3H membrane delivers an excellent Na2SO4 rejection of 96.92% coupled with a high water flux of 20.76 L m-2 h-1 bar-1. Moreover, it exhibits outstanding dye rejections (100%). Benefiting from the regulated interface, the biomimetic membrane demonstrates superior antifouling performance with a high flux recovery ratio (90.5%), outperforming the pristine and single-modified membranes. It also maintains robust long-term stability over 10 days of continuous operation. This study proposes a biomimetic membrane design strategy based on the collaborative regulation of transport channels and interfacial hydrogen-bond networks, which offers valuable guidance for the rational design of high-flux, highly selective, and antifouling separation membranes.