Recent Progresses on the Adsorption and Separation of Ions by Imprinting Routes

Imprinting techniques have been investigated extensively for the selective recognition of molecules and ions. However, few reviews focused on the state-of-the-art developments in ion imprinting technique. Ions and their analogs have a charge and usually similar physical and chemical properties, but less functional groups than molecules. The slight differences in charges, sizes and shapes of ions determine the structure-activity of metal-ligand complexes and imprinted materials. In this review, we focused on the internal connections between each component at coordination and polymerization stages with the affinity and selectivity of the imprinted materials. Advanced imprinting routes such as multiple-template, dual-template docking oriented ionic imprinting and nanocomposite ion imprinted membranes were elaborated. Computational simulation was highlighted for the prediction of functional monomers, binding mechanisms and selectivity. Multiple antifouling enhanced strategies for ion imprinted membranes were put forward to alleviate the trade-off relationship between treated volume and time. The review should provide researchers with new perspectives to explore ion imprinting technology and stimulate more creative breakthroughs in ion separation and purification fields.