Nano-wrinkled polyamide membrane preparation via heterogeneous surface-regulated interfacial polymerization for enhanced desalination performance

Abstract

Nano-wrinkled morphology and ultrathin thickness are desirable membrane structures in polyamide membranes, particularly for high-performance applications in desalination and wastewater treatment. In this study, we present the fabrication of a nano-wrinkled polyamide membrane with ultrathin thickness on a heterogeneous surface that features hydrophilic UiO-66-NH2 nanoparticles embedded on a hydrophobic polyethersulfone surface using a heterogeneous surface regulated interfacial polymerization approach. The presence of the heterogeneous surface induces the formation of aqueous phase microphases under the organic phase due to the unbalanced interfacial tension, which serves as a template for the formation of the polyamide film. This results in the creation of a nano-wrinkled polyamide layer upon drying. Furthermore, the hydrogen bonding interaction between the UiO-66-NH2 and piperazine (PIP) slows down the PIP release, which contributes to the ultrathin thickness of the polyamide layer. The polyamide membrane obtained in this study exhibits a pure water permeance (PWP) of 26.1 L bar−1·h−1·m−2 and a Na2SO4 rejection of 97.5 %. The PWP is 6.15 times higher than that of a control membrane fabricated through conventional interfacial polymerization. Our work offers a novel approach to tailor the structure of polyamide membranes via heterogeneous surface regulated interfacial polymerization, which has potential applications in environmental desalination.