Abstract: This research investigated the capabilities of caffeic acid-imprinted membrane (CA-IM) toward the selective extraction of caffeic acid (CA). A simpler surface-imprinted membrane using poly(vinylidene fluoride) as supporting membrane, CA as the template, ethylene glycol dimethacrylate as the cross-linker, and 4-vinylpyridine as the functional monomer was developed. The characterization of the membrane's surface after the polymerization process was analyzed with Fourier transform infrared spectroscopy and a scanning electron microscope. Molecular modeling showed a ratio of 1:4 for which template/monomer gave the highest at -18.09 kcal/mol. This indicates that this ratio can form a stable complex and a greater affinity toward CA. Batch rebinding and kinetics were performed and then followed by isotherm and kinetic adsorption modeling. Our results show that CA-IM fitted with Freundlich adsorption model and kinetic adsorption of CA-IM followed the second-order model. The selectivity experiment indicated that the adsorption capacity (1.497 mg/g), distribution coefficients, KD (1.939), and selectivity of polymers to CA were higher than for gallic acid and vanillic acid for CA-IM when compared to NIM. These results demonstrated that CA-IM is a capable and effective material for the selective adsorption and enrichment of CA compounds
Template and target information: caffeic acid, CA
Author keywords: caffeic acid, Molecular-imprinted membrane, polymerization, PVDF