Design of proton conducting solid biopolymer blend electrolytes based on chitosan‐potato starch biopolymers: Deep approaches to structural and ion relaxation dynamics of H+ ion

• Published in: Journal of applied polymer science 2022-10, Vol.139 (37), p.n/a
• Main Authors: Abdulwahid, Rebar T., B. Aziz, Shujahadeen, Kadir, Mohd F. Z.
• Format: Article
• Language: English
• Subjects: analysis; biodegradable polymer; Biopolymers; Chain dynamics; Chitosan; Dielectric loss; dielectric relaxation process; EEC modeling; Electrochemical impedance spectroscopy; electrolyte; Electrolytes; Energy storage; Equivalent circuits; impedance; Infrared spectroscopy; Inspection; ionic conductivity; Materials science; Modelling; Molten salt electrolytes; Polymer blends; Polymers; Polystyrene resins; Potatoes; Protons; Solid electrolytes; Spectrum analysis; structural (XRD and FTIR); Thiocyanates
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.52892

The need for flexible energy storage devices for advanced technologies has encouraged researchers to focus on environmental‐friendly biopolymers. In this work, chitosan (CS) and potato starch (PS) biopolymers are blended to prepare proton conducting solid electrolytes. Based on the X‐ray diffraction (XRD) inspection, the most amorphous blended film with the lowest crystallinity degree was selected to prepare polymer electrolytes. The variation in Fourier‐transform infrared spectroscopy (FTIR) bands were used to investigate the occurrence of interactions among the ammonium thiocyanate (NH4SCN) salt and CS:PS polymer blends. The experimental results of electrochemical impedance spectroscopy (EIS) were simulated with electrical equivalent circuit (EEC) modeling to determine the circuit elements. The highest value of 1.07×10−5 S cm−1 was recorded for the sample included 40 wt.% of dopant salt. The dielectric analyses were helpful in separating the regions ascribed to electrode and molecular polarizations. The combination of circuit elements achieved from the EEC modeling and Koops phenomenological interpretation is used to understand the behavior of the loss tangent (tanδ) pattern. The AC conductivity pattern followed Jonscher's power law. The relaxation dynamics interrelated with ions is explained using electric modulus approaches. The peaks hidden in the dielectric loss (ε′′) spectra, were manifested in the imaginary part of electric modulus (M′′) pattern. The M′‐M′′ patterns were used to shed light on the coupling between ionic motion and polymer chain dynamics.