Date of Award

12-1-2023

Thesis Type

masters

Document Type

Thesis (Restricted Access)

Divisions

advanced

Department

Institute for Advanced Studies

Institution

Universiti Malaya

Abstract

In this study, new sequences of fish gelatin (FG) as polymer host for solid polymer electrolytes (SPE) impregnated with ammonium nitrate (NH4NO3) are prepared via solvent-casting method. Chitosan (CS) was blended with FG to provide extra pathways for protonic migration to boost up the conductivity. From FESEM micrographs, the blend of 60 wt. % FG and 40 wt. % CS, (CF4) are found to be miscible to one and another and from XRD analysis it is confirmed that the ratio is the most amorphous with the lowest degree of crystallinity ~ 15. 38 %. The most amorphous electrolyte in the salted single polymer system is found to be FG25 and that of the salted blended system, is CFs40. The interactions between the material have been determined from the band shifts and changes of the peak’s wavenumber from FTIR spectroscopy analysis. The ionic conductivity of pure FG film has been identified to be 1.17 × 10-10 S cm-1 and optimised at 1.52 × 10-5 S cm-1 with the inclusion of 25 wt. % NH4NO3. The value has increased to 1.61 × 10-3 S cm-1 with the addition of 40 wt. % NH4NO3 in FG-CS polymer electrolytes system. The temperature dependence conductivity plot is Arrhenian. The variation in conductivity is accompanied by the changed in surface morphology as can be observed from FESEM analysis. Transport analysis showed that the trend in conductivity can be influenced by the mobility (μ), the diffusion coefficient (D) and number density (n) of ions. TGA and DSC are discussed to study the thermal properties of the electrolytes. The degradation temperature and glass transition temperature decreased as salt is added into the system due to the complexation of salt and the polymer. Tg decreased to 54.83 °C in FG25 and to 83.33 °C in CFs40. From TNM analysis, ions were found to be the dominant charge. tions values in the highest conducting electrolytes are 0.92 and 0.96 in FG25 and CFs40, respectively. LSV result confirms the suitability for the highest conducting electrolyte with ~2.6 V for both salted systems.

Note

Dissertation (M.A.) – Institute of Advanced Studies, Universiti Malaya, 2023.

15610-Norlin.pdf (241 kB)

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