Molecularly imprinted polymer particles having coordinated hydrogen bonding in covalent-imprinting for efficient recognition towards vanillin

This report explains the effects of vanillin-imprinted polymers showing hydrogen bonding coordinated in covalent-imprinting in core-shell particles. As new molecularly imprinted polymers (MIPs) for vanillin targets, this paper presents evidence for covalent-imprinting polymers having hydrogen-bonding coordination that is achieved using vanillin methacrylate (VMA) and methacrylic acid (MAA) for divinylbenzene (DVB) suspension polymerization. The stepwise polymerization can form core-shell uniform particles having about 0.3-2.5 μm diameter. The resultant vanillin-imprinted polymer containing VMA, MAA, and DVB segments enhanced separation of vanillin from other analogs, syringaldehyde and p-hydroxybenzaldehyde, showing a separation factor of 6.8. This result showed that the aid of hydrogen-bonded coordination of MAA in the covalent method with VMA imprinted the vanillin target. The influence of MAA in the imprinted polymer is shown by the separation performance having a high binding capacity and good selectivity, when both VMA and MAA segments were present in the polymer particles. Details of the effects of VMA and MAA amounts were investigated using target recognition by separation experiments.