Hypercrosslinked polymer membranes via interfacial polymerization for organic dye separations

Abstract Hypercrosslinked polymers (HCPs) have gained attention as promising materials for separation membranes due to their abundant porosity, low cost, ease of preparation, and excellent stability. Here, we demonstrate an interfacial-assisted polymerization approach to prepare continuous HCP membranes at room temperature. The method demonstrates versatility in constructing HCP membranes using various precursors, including small molecules and polymers. Specifically, the HCP membranes prepared using benzene as the monomer exhibit controllable thickness and a remarkable Brunauer-Emmett-Teller surface area of up to 855 m2 g−1. Leveraging physical size sieving and electrostatic interaction, the fabricated benzene-based membranes effectively reject small anionic dye molecules, such as Congo Red, Acid Fuchsin, and Methyl Orange, achieving rejection rates exceeding 93% while maintaining a high-water flux of up to 55 L m− 2 h− 1 bar− 1. This study shows a versatile approach for the design of HCP membranes capable of efficiently separating mixtures containing small molecules.