Fabrication of Double Template Imprinted Polymeric Membrane (DIPM) for simultaneous extraction of Quercetin and Caffeic acid bioactive compounds

Abstract

This study presents the performance of the molecular imprinted membrane (DIPM) towards the extraction of quercetin and caffeic acid. The PVDF membrane as the supporting membrane in this experiment were fabricated by utilizing quercetin and caffeic acid as the template, with EDGMA as the cross-linker and 4-VP as the functional monomer via surface polymerization process. The imprinted membranes were characterized through Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM) and Atomic Force Microscopic (AFM) to prove that the polymerization process was successfully done and covers the top layer of the PVDF membranes. The binding and kinetic test were conducted to investigate the binding capacity performance of the synthesized imprinted membranes in extracting caffeic acid molecules in a mixture solution of water/methanol (1/4, v/v). The binding analysis showed that the DIPM obtained the highest caffeic acid adsorption at 3.6314 mg/g at concentration of 14 mg/L and quercetin at 3.6766 mg/g at 14mg/L. Meanwhile, in kinetic analysis, the highest caffeic acid adsorption obtained at 5.3429 mg/g within 150 minutes whereas quercetin adsorption at 210min is 4.9651. The adsorption behavior of DIPM was found best fit the Freundlich isotherm while kinetic batch studies showed that the pseudo-second-order kinetic model is best describe on both quercetin and caffeic adsorption. The selectivity and permeability studies also have provided proof of the excellent membrane ability in recognition and adsorption of desired template. Thus, it can be concluded that the extraction of quercetin and caffeic acid using the molecular imprinted membrane was successfully done.