Optimization of Double Template Imprinted Polymeric Membrane (DIPM) using Design of Experiment (DOE)

Abstract

This study presence the optimization of the fabrication of double template imprinted polymeric membrane (DIPM) using surface imprinting polymerization method for simultaneous extraction of quercetin and caffeic acid bioactive compounds. Here, design of experiment (DOE) was used for the optimization of the fabrication then the performance of the DIPM was evaluated. The highest binding capacity of quercetin and caffeic acid was achieved in run #12 with ratio monomer/cross-linker (4:19.5, mmol/mmol) in DOE. The PVDF membrane was used as the supporting membrane in this experiment. The imprinted membranes was fabricated utilizing quercetin and caffeic acid as the template, EDGMA as the cross-linker and 4-VP as the functional monomer via polymerization process. The imprinted membranes were characterized through utilizing the Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM) and Atomic force microscope (AFM) to prove that the polymerization process was successfully done on the layer of the PVDF membranes. The double template imprinted polymeric membrane (DIPM) showed the thicker fibrous membrane structure compare to the non-imprinted membrane (NIM). The binding capacity, imprinting factor and selectivity coefficient test were conducted to investigate the binding capacity performance of this imprinted membranes to extract quercetin and caffeic acid molecules simultaneously in the mixture solution of water/methanol (3/2, v/v). The binding capacity showed that the DIPM obtained the highest quercetin and caffeic acid adsorption compare to NIM. Moreover, the imprinting factor of DIPM showed the highest quercetin and caffeic acid adsorption compare to rosmarinic acid and gallic acid. Other than that, selectivity coefficient of quercetin and caffeic acid on DIPM with respect to rosmarinic acid and gallic acid show higher selectivity coefficient compare to NIM.