Search

Although many researchers have done several studies on improving the selective separation performance of membrane materials, the conceptions and applications of membrane-based molecular imprinting separation and recognition with both high permselectivity and rebinding capacity have still faced challenges. Herein, for the first time, the bioinspired polydopamine (PDA)-modified porous regenerated cellulose membrane (pRCMs) with Au-based imprinting structure was constructed for the synthesis of molecularly imprinted nanocomposite membranes (MINMs); propranolol was used as template molecule. Importantly, based on the as-constructed PDA-modified layers, abundant Au-modified particles have been uniformly distributed onto the surfaces of membranes, and Au/PDA-based structures can be used as the imprinted-initiated factors for the preparation of sandwich-like-imprinted sites by developing a two-step temperature propranolol-imprinting method. Moreover, superior rebinding capacity (76.87 mg g−1) and selectivity (4.27–4.56) of MINMs has been successfully achieved; the as-prepared MINMs also showed excellent regeneration and permselectivity of propranolol (16.01–18.34) by constructing large amounts of propranolol-imprinted sites on the Au/PDA-based surface. Therefore, under optimized conditions, MINMs would finally obtain reproducible, accessible, and stable membrane-based separation system of the propranolol molecule.

Membrane-based separations can lessen the environmental effect of conventional techniques while increasing energy efficiency. Conventional adsorbents, on the other hand, enclose the majority of their functional sites in their dense structures, which causes problems with limited selectivity and adsorption capacity. By top-down method, based on the molecular structure and properties of artemisinin (Ars), a three-dimensional porous basswood membrane and a Metal-organic framework (MOF)-based modified layer were used as a dot-matrix initiator. The combination design of hydrophobic bond and complex bond interaction synergistic imprinting strategy was used to construct high density and high selectivity Ars molecularly imprinted polymers (MIPs) on the membrane, thus achieving the preparation of MOF-initiated imprinted self-supporting basswood membranes (MPIBSMs). When combined with the superhydrophilicity of the TiO2modified layer and the numerous accessible imprinting sites that MOF previously grown in situ on basswood provided, the resulting MPIBSMs displayed good adsorption capacity (81.2 mg g−1), selectivity coefficient (greater than 4.9), and ultrahigh water flux, eliminating the "trade-off" effect between membrane flux and selectivity. Additionally, the MPIBSMs are synthesized in a straightforward, pollution-free manner. Additionally, MPIBSMs were created in a green way. Finally, the aforementioned experimental findings and the environmentally sound synthetic technique imply that MPIBSMs have a wide range of possible applications in several fields, including environmental protection and selective separation.

Herein, according to the polydopamine (PDA)-based imprinting and thermal-induced imprinting methods, we reported on the development and applications of double-layer-imprinted mixed matrix membranes (DI-MMMs) through a dual-imprinted strategy, thereinto, the tetracycline (TC), one of the pollution-intensive pharmaceutical and personal care products, was chosen as template molecule. As to the first-TC-imprinted layer, the blended PDA-based TC-imprinted activated carbon (AC) and SiO2were both used for the preparation of membrane. Next, κ-carrageenan-modified graphene oxide (GO) nanosheets would be regarded as the surface-loaded layer to support the thermal-induced imprinting synthesis (second-TC-imprinted layer). Importantly, high adsorption capacity at around at 106.44 mg/g and fast adsorption rate (within 60 min) had been successfully obtained. Importantly, permselectivity rates (β) of our imprinting membranes were obtained as 3.60, 3.33 and 3.51, respectively. Overall, based the practical selective separation and scalability analysis, we believed that the as-prepared DI-MMMs with high-intensitive recognizability and permeability of template molecule would provide a possibility for breaking the permeability-selectivity trade-off of molecularly imprinted membrane materials.