Surface Functionalization of PVDF Membrane with a Naringin-Imprinted Polymer Layer Using Photo-Polymerization Method

The aim of this work was the preparation of molecularly imprinted membranes by surface modification of microfiltration polyvinylidene fluoride membranes with a thin layer of molecular imprinted polymer by UV irradiation. The flavonoid naringin (4,5,7-trihydroxyflavanone-7-rhamnoglucoside) was used as template molecule. The compound 4-vinylpyridine was used as functional monomer. Benzoin ethyl ether and ethylene glycol dimethacrylate were used as photo-initiator and cross-linker, respectively. Membranes were also modified in the absence of naringin and used as reference (blank). Imprinted membranes prepared in this work could be applied as new separation devices in affinity filtrations aimed to reduce the naringin content in grapefruit and improve its benefit properties. The method used to prepare them offers the advantage of combining the mechanical integrity of the membrane support with the selective recognition properties of the imprinted polymer layer. The recognition properties of all prepared membranes were evaluated by their capability to retain naringin in aqueous solution during filtration tests. Results showed that imprinted membranes exhibited specific binding properties for template molecules. Blank membranes only showed non-specific binding. The selectivity of the naringin-imprinted membranes was tested evaluating their bound property toward the rutin, a structural analogue of naringin.