Enhancing H+ conduction through glycolic acid-doped alginate-PVA based biopolymer electrolytes

This study investigates the development of a biopolymer blend electrolyte composed of alginate and poly (vinyl alcohol) (PVA), doped with glycolic acid (GA) to enhance H + conductivity. The addition of GA significantly impacts the biopolymer blend's physicochemical properties and ionic conduction performance. Fourier transform infrared (FTIR) spectroscopy verified the intricate interactions and hydrogen bonding between the alginate-PVA matrix and GA. The addition of GA was shown to increase the amorphous phase, as observed through X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. This increase in the amorphous phase was found to enhance the thermal stability. Impedance analysis demonstrated a significant increase in ionic conductivity from approximately ∼10⁻⁸ S cm⁻ 1 for the undoped blend to 3.45 × 10⁻⁵ S cm⁻ 1 with 30 wt% GA (sample GA-30). The enhanced H + conduction behaviour was consistent across various temperatures, adhering to the Arrhenius rule. These findings suggest that the alginate-PVA-GA system is a promising candidate for efficient proton transport applications. • A bio-based polymer blend electrolyte composed of alginate-PVA containing H + carriers has been successfully prepared. • Amorphous Structure : GA doping transforms alginate-PVA into a highly amorphous, ion-conductive structure. • Strong Hydrogen Bonding : FTIR shows enhanced hydrogen bonding, aiding proton conduction via Grotthuss mechanism. • Thermal Stability : TGA confirms GA-doped alginate-PVA maintains thermal stability and boosts proton conductivity. • Enhanced Proton Conductivity : Glycolic acid-doped alginate-PVA boosts conductivity to 3.45 × 10⁻⁵ S cm⁻ 1 .