Performance Evaluation of Sulfonated Chitosan-TEOS Membranes: Implications for Direct Methanol Fuel Cell Applications

Abstract

This research examines the development and evaluation of sulfonated chitosan-TEOS composite membranes for prospective application in direct methanol fuel cells (DMFCs). We enhanced the characteristics of chitosan derived from shrimp shells by using tetraethyl orthosilicate (TEOS) and sulfuric acid. We employed Fourier-transform infrared (FTIR) spectroscopy to identify the chemical constituents of the membranes. Subsequently, we assessed their water contact angle (WCA), thermogravimetric analysis (TGA), and electrochemical impedance spectroscopy (EIS) to determine their hydrophilicity, thermal resistance, and electrochemical activity. The results demonstrated that membrane B had the lowest water contact angle, indicating superior hydrophilicity and proton conductivity. The TGA results indicated the membrane thermal stability, exhibiting significant weight retention up to 500 °C, affirming their heat resistance. We assessed the membranes' selectivity, revealing an ideal equilibrium between elevated proton conductivity and diminished methanol permeability. The results indicate that sulfonated chitosan-TEOS composite membranes are promising for DMFCs applications. This underscores the opportunity to modify their composition to enhance performance in sustainable energy solutions.