在硫酸酸交换膜中化和性金属酸的移动性
Vitaly I Volkov1,2, Nikita A Slesarenko1, Alexander V Chernyak1,2
1Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia.
Membranes
|May 26, 2023
概括
这项研究揭示了Nafion和MSC膜中的离子运动和水动态如何取决于膜结构和离子水合. 确定了不同的离子行为,比如和与水一起移动,而在群体之间跳跃.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学是一种材料科学.
- 物理化学 物理化学
背景情况:
- 了解聚合物膜中的离子运输对于燃料电池和电池等应用至关重要.
- 纳和改性硫聚烯 (MSC) 膜是广泛使用的离子交换材料.
研究的目的:
- 阐明Nafion和MSC膜中电离子道结构,阴离体水化和离子/水流动性之间的关系.
- 为了研究Li+,Na+和Cs+离子和水分子在这些膜内的转化流动性.
主要方法:
- 利用1H,7Li,23Na和133Cs的自旋放松技术来估计局部离子和水的移动性.
- 使用脉冲场梯度核磁共振 (PFG-NMR) 来测量自我扩散系数.
- 从水分子的温度依赖的1H化学转移中计算出阴离子化数.
主要成果:
- 宏观的质量转移是由离子和水在硫酸盐群附近的运动控制的.
- 和离子,具有比水的键能量更高的化能,与水分子集体移动.
- 酸具有较低的水合能,在硫酸盐组之间表现出直接的跳跃.
- 在MSC膜中计算和实验导电率之间的差异表明孔隙/通道系统的异质性.
结论:
- 该研究提供了关于离子交换膜中子特异性运输机制的见解.
- 化能量在决定相对于水的离子流动性方面发挥着关键作用.
- 膜异质性显著影响导电性测量,特别是在MSC系统中.
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