• M H HAMSAN

Articles written in Bulletin of Materials Science

• Dextran from Leuconostoc mesenteroides-doped ammonium salt-based green polymer electrolyte

Biopolymer electrolytes based on dextran from Leuconostoc mesenteroides doped with ammonium nitrate (NH$_4$NO$_3$) are synthesized via a solution cast method. Fourier transform infrared analysis is used to determine the complexation between cation from the salt with functional groups of dextran. The ionic conductivity of undoped dextran film at room temperature is identified as $(8.24 \pm 0.31) \times 10^{−11}$ S cm$^{−1}$. A conductivity of $(3.00 \pm 1.60) \times 10^{−5}$ S cm$^{−1}$ isachieved with the inclusion of 20 wt% NH$_4$NO$_3$ to the pure dextran film. The conductivity at a high temperature of the electrolyte obeys Arrhenius theory. Field emission scanning electron microscopy results show that the highest conducting sample has a porous surface. Results from the dielectric study show a non-Debye characteristic.

• Influence of NH$_4$Br as an ionic source on the structural/electrical properties of dextran-based biopolymer electrolytes and EDLC application

Biopolymer electrolytes (BPEs), consisting of ammonium bromide (NH$_4$Br) as the ionic provider and dextran(Leuconostoc mesenteroides) as the polymer host, are prepared by the solution cast technique. Interactions of cations from the salt have been confirmed with hydroxyl (OH) and glycosidic linkage (C–O–C) groups of dextran via Fourier transforminfrared analysis. Electrolyte with 20 wt% NH4Br maximized the ionic conductivity up to $(1.67 \pm 0.36) \times 10^{−6}$ S cm$^{−1}$. The trend of conductivity has been verified by field emission scanning electron microscopy, where the electrolyte surface became rough as the concentration of NH4Br exceeded 20 wt%. The contribution of ions as the main charge carrier in theBPE is confirmed by transference number analysis as $t_{\rm ion} = 0.92$ and $t_e = 0.08$. From linear sweep voltammetry, it is found that the highest conducting BPE in this work is electrochemically stable from 0 to 1.62 V. The fabricated electrochemical double-layer capacitor (EDLC) has been tested for 100 charge–discharge cycles and verified by cyclic voltammetry.

• Bulletin of Materials Science

Volume 43, 2020
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Continuous Article Publishing mode

• Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020

Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020

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