Potential of sodium alginate/titanium oxide biomembrane nanocomposite in DMFC application

Abstract

A proton exchange membrane was synthesized consuming a sodium alginate biopolymer as the matrix and titanium oxide as the nanofiller. The titanium oxide content varied from 5 to 25 wt%. The biomembrane nanocomposite performs better than the pristine sodium alginate membrane based on liquid uptake, methanol permeability, proton conductivity, ion exchange capacity, and oxidative stability outcomes. The unique properties of sodium alginate and titanium oxide lead to outstanding interconnections, thus producing new materials with great characteristics and enhanced performance. The highest proton conductivity achieved in this study is 17.3 × 10-3 S cm-1, which performed by SAT5 (25 wt%) membranes at 70°C. An optimal content of titanium oxide enhances the conductivity and methanol permeability of the membrane. Additionally, the hydrophilicity of pure sodium alginate is greatly reduced and achieves a good liquid uptake capacity and swelling ratio. The characteristics of the SA/TiO2 biomembrane nanocomposite were determined with field emission scanning electron microscope, Fourier transform infrared, X-ray diffraction, thermal gravimetric analysis/differential scanning calorimetry, and mechanical strength analysis. © 2019 John Wiley & Sons, Ltd.