离子液体的结晶动力学:阴离子基链长度和热史的影响
B Yao1, V Morales Alvarez1, M Paluch1
1Institute of Physics, The University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland.
The journal of physical chemistry. B
|June 26, 2024
概括
基链长度显著影响四基酸离子液体的结晶率,但不影响离子流动性或玻璃过渡温度. 热史也会影响结晶速度.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 离子液体 (ILs) 是具有低点的盐,可为各种应用提供调节性质.
- 基二三甲基硫) 胺 ([P666,n][TFSI]) ILs因其独特的热和电化学行为而受到研究.
- 了解ILs中的结构-属性关系对于设计先进材料至关重要.
研究的目的:
- 研究不同链长度对[P666,n][TFSI]离子液体结晶动力学和离子流动性的影响.
- 确定热史 (冷与融结晶) 对这些ILs结晶行为的影响.
- 为了将结构修改与观察到的离子导电率变化相关联.
主要方法:
- 差分扫描热量计 (DSC) 用于研究热过渡和结晶动力学.
- 宽带介电光谱 (BDS) 探测离子动力学和电导率.
- 第四个基链长度的系统变化 (n = 2, 6, 8, 12) 在酸中.
主要成果:
- 液相中的玻璃过渡温度 (Tg) 和离子动态在很大程度上对链长度的变化没有敏感.
- 结晶动力学在很大程度上取决于第四个链的长度.
- 结晶率受到样品热史 (冷结晶与结结晶) 的显著影响.
- 在超冷液体和晶体阶段,离子导电性仍然很大,显示出离子结构的独立性.
结论:
- 虽然结晶的基本性质在同源序列中是一致的,但动力学与基链长度有很大差异.
- 阴离子结构对离子流动性和玻璃过渡的影响有限,但对结晶行为有明显的影响.
- 这些发现强调了基链长度和热史在控制离子液体的固态特性方面的重要性.
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