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测量 (乙胺+K/Na SCN) 深溶剂的温度依赖性介电松:通过计算机模拟解码阴离子身份的影响

Jayanta Mondal¹, Dhrubajyoti Maji¹, Ranjit Biswas¹

¹Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700106, India.

The Journal of chemical physics

|February 29, 2024

概括

在深溶剂 (DES) 中用 (Na+) 取代 (K+),改变了它们的介电松和粘度. 这项研究揭示了阴离子身份如何影响这些重要材料中的键和结构动态.

科学领域:

物理化学物理化学
材料科学材料科学材料科学
计算化学计算化学

背景情况:

深度浸泡溶剂 (DES) 是可调节的溶剂系统,在各种化学过程中具有应用.
了解构成性离子对DESs物理化学性质的影响,对于其有针对性的设计和应用至关重要.
介电松 (DR) 是一种强大的技术,用于探测分子动力学和缩相中的相互作用.

研究的目的:

研究用 (Na+) 代替 (K+) 对特定DESs的介电松反应的影响.
通过实验和计算方法阐明这些DES中阴离子依赖行为的微观起源.
为了将键和结构秩序的变化与观察到的介电性质相关联.

主要方法:

在0.2-50 GHz的频率范围内,对含有K+和Na+的DES进行了温度依赖的介电松 (DR) 测量.
用计算机模拟来建模DR反应,包括去除离子电流贡献.
差分扫描热量计 (DSC) 用于确定玻璃过渡温度,并通过模拟分析结和方向顺序.

主要成果:

用Na+取代K+导致多Debye放松和静电介电常数 (ɛs) 的下降.
与K+-DES相比,含Na+的DES表现出更强的DR时间的粘度解和更高的玻璃过渡温度.
模拟显示了平均键的减少和Na+替代时的指向挫折的增加,与测量的大小线性相关.

结论:

电离子标识 (K+与Na+) 显著影响研究DES的介电性质,动力学和结构.
观察到的差异归因于结,方向顺序和脆弱性的变化,正如模拟和DSC所显示的那样.
模拟放松动力学为实验观察到的阴离子依赖介电放松时间提供了微观的解释.

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