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arXiv 2302.01799physics.chem-phcond-mat.stat-mechphysics.comp-ph
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电解质中的电噪声:理论展望

Electrical noise in electrolytes: a theoretical perspective

Thê Hoang Ngoc Minh, Jeongmin Kim, Giovanni Pireddu, Iurii Chubak, Swetha Nair, Benjamin Rotenberg

摘要:

看似无关的实验,如通过纳米管的电解质传输,纳米尺度电化学,NMR弛豫和表面力平衡测量,所有探针的电波动:电流,电荷和极化,场梯度(四极核)和耦合的质量/电荷密度。这些不同的可观测量的波动来自于离子和溶剂分子的相同的基本微观动力学。原则上,这些动态的相关长度和时间尺度被编码在动态结构因子中。然而,为跨越许多数量级的频率和波矢量对后者进行建模仍然是一个巨大的挑战,以解释物理过程中的实验,例如溶剂化动力学,扩散,离子之间的静电和流体动力学相互作用,与固体表面的相互作用等。我们强调收费的核心作用-电荷动态结构因素在电解质中的电观测值的波动,并提供了一个统一的观点,在各种互补的实验。我们进一步分析了这个量在特殊情况下的NaCl水溶液电解质,使用模拟与明确的离子和明确或隐含的溶剂。我们讨论了标准泊松-能斯特-普朗克理论捕捉模拟结果的能力,以及如何改进预测。最后讨论了离子和水对总电荷涨落的贡献。这项工作说明了为全面了解块状和受限电解质中的电波动而正在进行的努力,以便使实验学家能够破译测量的电噪声中编码的微观特性。

英文摘要:

Seemingly unrelated experiments such as electrolyte transport through nanotubes, nano-scale electrochemistry, NMR relaxometry and Surface Force Balance measurements, all probe electrical fluctuations: of the electric current, the charge and polarization, the field gradient (for quadrupolar nuclei) and the coupled mass/charge densities. The fluctuations of such various observables arise from the same underlying microscopic dynamics of the ions and solvent molecules. In principle, the relevant length and time scales of these dynamics are encoded in the dynamic structure factors. However modelling the latter for frequencies and wavevectors spanning many orders of magnitude remains a great challenge to interpret the experiments in terms of physical process such as solvation dynamics, diffusion, electrostatic and hydrodynamic interactions between ions, interactions with solid surfaces, etc. Here, we highlight the central role of the charge-charge dynamic structure factor in the fluctuations of electrical observables in electrolytes and offer a unifying perspective over a variety of complementary experiments. We further analyze this quantity in the special case of an aqueous NaCl electrolyte, using simulations with explicit ions and an explicit or implicit solvent. We discuss the ability of the standard Poisson-Nernst-Planck theory to capture the simulation results, and how the predictions can be improved. We finally discuss the contributions of ions and water to the total charge fluctuations. This work illustrates an ongoing effort towards a comprehensive understanding of electrical fluctuations in bulk and confined electrolytes, in order to enable experimentalists to decipher the microscopic properties encoded in the measured electrical noise.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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