Bocharova Vera, Genix Anne-Caroline, Kisliuk Alexander, Sala Gabriele, Osti Naresh C, Mamontov Eugene, Sokolov Alexei P
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, France.
J Phys Chem B. 2020 Nov 19;124(46):10539-10545. doi: 10.1021/acs.jpcb.0c07549. Epub 2020 Nov 7.
Polymerized ionic liquids (PolyILs) are promising candidates for a broad range of technologies. However, the relatively low conductivity of PolyILs at room temperature has strongly limited their applications. In this work, we provide new insights into the roles of various microscopic parameters controlling ion transport in these polymers, which are crucial for their rational design and practical applications. Using broadband dielectric spectroscopy and neutron and light scattering techniques, we found a clear connection between the activation energy for conductivity, fast dynamics, and high-frequency shear modulus in PolyILs at their glass transition temperature (). In particular, our analysis reveals a correlation between conductivity and the amplitude of fast picosecond fluctuations at , suggesting the possible involvement of fast dynamics in lowering the energy barrier for ion conductivity. We also demonstrate that both the activation energy for ion transport and the amplitude of the fast fluctuations depend on the high-frequency shear moduli of PolyILs, thus identifying a practically important parameter for tuning conductivity. The parameters recognized in this work and their connection to the ionic conductivity of PolyILs set the stage for a deeper understanding of the mechanism of ion transport in PolyILs in the glassy state.
聚合离子液体（PolyILs）是众多技术领域中颇具潜力的候选材料。然而，PolyILs在室温下相对较低的电导率严重限制了它们的应用。在这项工作中，我们对控制这些聚合物中离子传输的各种微观参数的作用有了新的认识，这对于它们的合理设计和实际应用至关重要。通过宽带介电谱以及中子和光散射技术，我们发现在玻璃化转变温度（）下，PolyILs的电导率活化能、快速动力学和高频剪切模量之间存在明显的联系。特别是，我们的分析揭示了电导率与在 时快速皮秒波动幅度之间的相关性，这表明快速动力学可能参与降低离子导电的能垒。我们还证明，离子传输的活化能和快速波动的幅度都取决于PolyILs的高频剪切模量，从而确定了一个用于调节电导率的实际重要参数。这项工作中识别出的参数及其与PolyILs离子电导率的联系，为深入理解玻璃态下PolyILs中的离子传输机制奠定了基础。
