Solvent-driven controllable molecularly imprinted membrane with switched selectivity and fast regenerability enabled by customized bifunctional monomers

Abstract

Ensuring both selective separation and fast regenerability is still a challenge, especially for long-term operation in a harsh water system. Sustainable and effective development of molecularly imprinted membranes is highly desired. Herein, we propose a type of solvent-driven controllable molecularly imprinted membranes (CS-BMIMs) to realize the switched selectivity and fast regenerability by customized bifunctional monomers. The stable supramolecular envelope interaction and hydrogen bonds between the bifunctional monomers and the phenolic hydroxyl group is introduced to regulate the selectivity of BPA. The selectivity coefficients of CS-BMIMs can reach 7.52 (αBPA/BP) and 7.97 (αBPA/HQ). Poly (ethylene glycol) unit-containing chain of dynamic solvent-responsive cross-linker drives the swelling and deswelling polymer chains to accelerate the regenerability. Significantly, BPA can be readily adsorbed into the imprinted sites in a 25% methanol (MeOH) aqueous solution with an adsorption capacity of 41.88 mg g−1 while completely desorbed in 100% MeOH following the deswelling of BPA-imprinted sites. Compared with the ordinary elution methods (VMeOH: Vacetic acid, 9: 1), the solvent-driven controllable method displayed a fast adsorption/desorption process with desirable regenerability (15 min). Moreover, the proposal of “specially designed” stimulus–response material enriches the designability and options of membrane separation in water treatment, thereby laying a foundation for developing decontamination of the water.