Synthesis and characterization of Dextran, poly (vinyl alcohol) blend biopolymer electrolytes with NH <sub>4</sub> NO <sub>3</sub> , for electrochemical applications
T. Maheshwari, K. Tamilarasan, S. Selvasekarapandian, R. Chitra, M. Muthukrishnan
Abstract
New biocompatible biopolymer membranes have been synthesized from naturally occurring bacterial polysaccharide Dextran, which is efficacious versatile polymer known for medicinal applications. In the present study, biodegradable solid polymer electrolytes based on Dextran:Poly vinyl alcohol (PVA) with different composition of ammonium nitrate (NH4NO3) are prepared by solution casting technique with double distilled water as a solvent. The prepared polymer membranes have been characterized by various techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetric (DSC), AC impedance, linear sweep voltammetry (LSV), and transference number measurement. The amorphous nature of the polymer membrane is enhanced due to the addition of ammonium nitrate has been confirmed by X-ray diffraction analysis. The complex formation between the host polymer and the salt has been studied by Fourier transform infrared spectroscopy. The highest ionic conductivity of 1.66 × 10−3 S/cm for the composition 700 mgDextran:300 mgPVA:450 mgNH4NO3 has been observed by AC impedance spectroscopy at room temperature. The electrochemical stability of the highest conducting polymer electrolyte (700 mgDextran:300 mgPVA:450 mgNH4NO3) has been observed as 3.32 V by Linear sweep voltammetry. From Wagner’s polarization method transference number of highest conducting polymer electrolyte has been calculated as 0.99. Finally primary proton battery has been constructed using the highest conducting polymer membrane of 700 mgDextran:300 mgPVA:450 mgNH4NO3. Its open circuit voltage is measured as 1.51 V and its performance is studied.