Abstract

In this report, the relationship between the ionic conduction properties of alginate (AL) based biopolymer electrolyte (BE), and the amount of NH₄Cl dopant and ethylene carbonate (EC) plasticizer is discussed. The BE was prepared via a solution casting method and characterized by using Fourier transform infrared (FTIR) and electrical impedance spectroscopy (EIS), respectively. The highest ionic conductivity attained for the AL-NH₄Cl BE was 3.18 × 10⁻⁸ S cm⁻¹ for 8 wt.% of NH₄Cl. Nonetheless, an increased optimum value of 1.46 × 10⁻⁶ S cm⁻¹ was obtained when plasticized with 4 wt.% of EC. It was observed that with the addition of the EC content between the range of 1 wt.% and 7 wt.% into the AL-NH₄Cl with 8 wt.% salt content increased the flexibility of the AL chains to facilitate free H⁺ ion transport. The weak bonding created through EC - NH₄⁺ allows higher dissociation of proton ions (H⁺), allowing more interaction to occur on the AL polymer backbone. These ions will hop from one complex site of AL to another, as revealed by FTIR analysis. Through the deconvolution analysis of the BE systems, it was demonstrated that the ionic conductivity for both systems was governed by the enhancement of the free ions fraction which, in turn, increased the number of mobile ions upon the addition of NH₄Cl.

摘要

在本报告中，讨论了基于藻酸盐 (AL) 的生物聚合物电解质 (BE) 的离子导电性能与 NH ₄ Cl 掺杂剂和碳酸亚乙酯 (EC) 增塑剂的量之间的关系。BE 通过溶液浇铸法制备，并分别使用傅里叶变换红外 (FTIR) 和电阻抗光谱 (EIS) 进行表征。对于 8wt.% 的 NH ₄ Cl ，AL-NH ₄ Cl BE获得的最高离子电导率为3.18 × 10 ^-8 S cm ^-1。尽管如此，增加的最佳值 1.46 × 10 ^-6 S cm ^-1当用 4 重量％的 EC 增塑时获得。据观察，将 1 wt.% 至 7 wt.% 范围内的 EC 含量添加到具有 8 wt.% 盐含量的 AL-NH ₄ Cl 中，增加了 AL 链的柔韧性，以促进游离 H ⁺离子传输。通过 EC - NH ₄ ⁺产生的弱键使质子离子 (H ⁺)，允许在 AL 聚合物主链上发生更多的相互作用。正如 FTIR 分析所揭示的那样，这些离子将从 AL 的一个复杂位点跳跃到另一个位点。通过对 BE 系统的解卷积分析，表明两个系统的离子电导率受自由离子分数的增强控制，这反过来又增加了添加 NH ₄ Cl后的移动离子数量。