Fabrication and characterization of modified microcrystalline cellulose membrane as proton exchange membrane for direct methanol fuel cell

Abstract

In this study, we report fabrication, and characterization of biopolymer-based membrane composite using microcrystalline cellulose (MCC) modified with phosphotungstic acid (PTA) and imidazole. The cellulose membrane was prepared by phase inversion method. The physicochemical properties of composite membranes were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Electrochemical impedance spectroscopy (EIS). The regenerated cellulose membrane water uptake ability, and methanol uptake, derived from absorption of aqueous electrolytic solutions, also evaluated in this study to assess the successful applicability of the proposed membranes as PEM electrolytes for direct methanol fuel cell devices. XRD analysis shown that modification of the regenerated cellulose membrane had no effect on phase on cellulose membrane and cellulose membrane still retain the cellulose II crystalline structure which also confirmed with IR spectra of modified membrane which glycosidic and CH2 vibration peak around 900 and 1420 cm−1 that indicate intramolecular hydrogen bond did not alter after addition of dopant. Results indicate that modification of MCC with acid and base dopant could improve water management of regenerated membrane while also lessen methanol permeability inside membrane. Thus, modified regenerated cellulose membrane has high potential as alternative proton exchange membrane for direct methanol fuel cell.