Multilayer-functionalized molecularly imprinted nanocomposite membranes for efficient acteoside separation

Acteoside (ACT) and echinoside (ECH) had similar structure and property in the phenylethanoid glycosides (PhGs), thus the selective separation of ACT and ECH was a bottleneck problem. In this study, ACT was used as template molecule, and multilayer-functionalized of molecularly imprinted nanocomposite membranes (A-MINMs) were designed to efficient ACT separation. The A-MINMs were fabricated by using polydopamine (PDA), polyethylenimine functionalized mesoporous silica (PEI/MCM-41) and ACT imprinted layer to modify the surface of polyvinylidene fluoride (PVDF). The PDA layer was a stable surface adhesive, and the filler PEI/MCM-41 was uniformly bonded to the PVDF membrane surface, thus constructing the second layer on the membrane surface. The PEI/MCM-41 layer adjusted the pore uniformity of the membrane surface, and contained abundant amino groups, which provided an ACT imprinted platform to trigger the imprinted polymerization to form an imprinted layer. The ACT imprinted layer had a large number of ACT imprinted sites and cavities, which could specifically recognize ACT, realizing the efficient ACT separation. The results indicated the high rebinding capacity (108.74 mg/g) and permselectivity (βACT/ECH = 9.43) of A-MINMs. Therefore, multilayer-functionalized A-MINMs has a potential application prospect in the field of natural product separation membrane materials.