溶解在双块共聚物中离子扩散的作用:通过建模了解分子重量效应
Youngmi Seo1, Kuan-Hsuan Shen1, Jonathan R Brown1
1William G. Lowrie Department of Chemical and Biomolecular Engineering , The Ohio State University , 151 West Woodruff Avenue , Columbus , Ohio 43210 , United States.
Journal of the American Chemical Society
|November 2, 2019
概括
分子动力学模拟显示,盐添加的二块共聚物中的离子扩散取决于离子溶解强度和度. 局部离子聚合,而不是界面宽度,解释了减少的扩散,加剧了离子扩散和扩散.
科学领域:
- 材料科学
- 聚合物化学
- 计算化学
背景情况:
- 由于其离子导电性和机械强度,盐化双块共聚物对运输应用具有前景.
- 实验研究显示出反直觉的传输趋势,比如分子量增加的离子导电.
- 导电相中的强离子溶解是关键特征.
研究的目的:
- 研究盐化二块共聚物的离子运输的分子基础.
- 使用分子动力学模拟来复制实验观察到的趋势.
- 探索离子溶解,度和聚合物结构对离子扩散的影响.
主要方法:
- 粗的分子动力学模拟.
- 包含一个1/r^4的潜力来模拟离子溶解效应.
- 离子度,溶解强度和聚合物分子重量的系统变化.
主要成果:
- 离子扩散可以随着离子度的增加或减少而增加,这取决于溶解强度.
- 增加分子重量增强了离子扩散,特别是在更强的溶解或离子-离子相互作用时.
- 局部离子聚合,而不是接口宽度,是减少扩散的主要原因.
- 由Flory chi参数和分子重量影响的界面化促进了均的离子分布和扩散.
结论:
- 分子动力学模拟成功地复制了双块共聚物中观察到的离子运输趋势.
- 离子溶解和局部离子聚合是控制离子扩散的关键因素.
- 通过聚合物设计控制接口特性可以优化技术应用的离子传输.
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