基于离子体的物理水凝:通过NMR探测液体-凝过渡,链和反离子动力学
Sarrah Mezdari1, Lingsam Tea1, Juliette Sirieix-Plénet1
1Sorbonne Université, CNRS, Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), 4 place Jussieu, F-75005 Paris, France. natalie.malikova@sorbonne-universite.fr.
Physical chemistry chemical physics : PCCP
|November 12, 2025
概括
这项研究揭示了离子凝如何形成交叉链接. 在液体-凝过渡过程中,对流体不动化,影响链路动力学和网络刚性,化物系统显示出比化物系统更高的链路流动性.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 基于离子体的物理水凝是多功能材料,具有对其离子成分敏感的特性.
- 了解液凝过渡对于定制水凝网络形成和宏观性质至关重要.
研究的目的:
- 在液体-凝过渡过程中调查离子多电解质链和对应链的局部环境和动态.
- 阐明 counterions (F− 和 Cl−) 在离子体水凝的交联过程中的作用.
- 为了比较水凝中的链动力学和网络刚性,用不同的 counterions.
主要方法:
- 核磁共振 (NMR) 光谱,包括1H和19F NMR化学转移,峰值强度和峰值扩展.
- 脉冲场梯度核磁共振 (PFG-NMR) 用于研究链和 counterion 动力学.
- 与化物 (F−) 和化物 (Cl−) 相对应的离子凝的比较.
主要成果:
- 对离子链和对子链的NMR信号强度的显著损失表明,在液体-凝过渡过程中,它们在交叉连接网络中的固定.
- 化物对应物表现出脱效应,并在凝时增加峰值扩大,证实它们参与交叉链形成.
- 与化相比,NMR可见链的扩散系数在化水凝中大约是化水凝的两倍,这表明在F−的存在下,链的刚性增加了.
结论:
- 在以离子为基础的物理水凝中,对方的参与对于交叉链的形成至关重要.
- 反离子的性质显著影响水凝网络内的电离子链的动态和刚性.
- 与化物对应物相比,化物对应物会导致更硬的离子链,这可能是由于更强的相互作用和水合效应.
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