Koymeth S, Yao B, Paluch M, Dulski M, Swadzba-Kwasny M, Wojnarowska Z
Faculty of Science and Technology, Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland.
Faculty of Science and Technology, Institute of Materials Science, University of Silesia in Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland.
J Phys Chem B. 2024 May 23;128(20):5109-5117. doi: 10.1021/acs.jpcb.3c08506. Epub 2024 May 8.
In this study, we employed dielectric spectroscopy to investigate the effect of temperature and pressure on the ion dynamics of phosphonium ionic liquids (ILs) differing by the length of an alkyl chain, [P][TFSI] ( = 2, 6, 8, 12). We found that both temperature and pressure dependence of dc-conductivity (σ) determined for all examined ILs herein exhibit unique characteristics, unusual for aprotic ILs. Two regions differing by ion self-organization have been identified from the derivative analysis of σ() data. On the other hand, isothermal measurements performed at elevated pressure revealed a unique concave-convex character of σ() dependences, resulting in a clear minimum in the pressure behavior of activation volume. Such an inflection point characterizing the pressure dependence of σ in [P][TFSI] ILs can be considered an inherent feature of ion dynamics governed by structural self-assembly. Our results offer a unique perspective to link the ion mobility at various - conditions to the nanostructural organization of ionic systems.
在本研究中，我们采用介电谱来研究温度和压力对不同烷基链长度的鏻离子液体（ILs）[P][TFSI]（ = 2、6、8、12）离子动力学的影响。我们发现，本文中所有检测的ILs的直流电导率（σ）的温度和压力依赖性均表现出独特的特征，这对于非质子ILs来说是不寻常的。通过对σ()数据的导数分析，确定了两个因离子自组织而不同的区域。另一方面，在高压下进行的等温测量揭示了σ()依赖性的独特凹凸特性，导致活化体积的压力行为出现明显最小值。这种表征[P][TFSI] ILs中σ压力依赖性的拐点可被视为由结构自组装控制的离子动力学的固有特征。我们的结果为将各种条件下的离子迁移率与离子系统的纳米结构组织联系起来提供了独特的视角。
