Theory and simulation of electrokinetic fluctuations in electrolyte solutions at the mesoscale
Theory and simulation of electrokinetic fluctuations in electrolyte solutions at the mesoscale
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介观尺度电解质溶液动电涨落的理论与模拟
DOI：
10.1017/jfm.2022.377
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发表时间：
2022
影响因子：
3.7
通讯作者：
Li, Zhen
中科院分区：
文献类型：
--
作者：
Deng, Mingge;Tushar, Faisal;Bravo, Luis;Ghoshal, Anindya;Karniadakis, George;Li, Zhen
电解质溶液在储能器件中起着重要的作用，其性能在很大程度上依赖于亚微米尺度的电动过程。虽然波动和随机特性在小尺度下变得更加关键，但长程库仑相互作用对具有波动流体动力学和静电相互作用的流体系统的理论分析和模拟提出了特殊的挑战。在这里，我们提出了一个基于Landau-Lifshitz理论的理论框架，推导出电解质溶液中波动相关性的封闭形式表达式，表明离子浓度波动与流体动力学波动的去相关过程明显不同，这为理解耦合波动流体动力学和电动力学的输运现象提供了见解。此外，我们还分别用分子动力学（MD）和介观荷电耗散粒子动力学（cDPD）模拟了涨落电动力学体系，发现局域电荷密度的空间概率密度函数在亚纳米尺度下服从γ分布（即），表明存在一个下限的长度尺度的中尺度模式使用高斯起伏。从全原子MD和介观cDPD模拟计算的流体动力学和电动力学波动的时间相关函数，表现出良好的一致性与理论预测的基础上的线性波动流体动力学理论。
Electrolyte solutions play an important role in energy storage devices, whose performance relies heavily on the electrokinetic processes at sub-micron scales. Although fluctuations and stochastic features become more critical at small scales, the long-range Coulomb interactions pose a particular challenge for both theoretical analysis and simulation of fluid systems with fluctuating hydrodynamic and electrostatic interactions. Here, we present a theoretical framework based on the Landau–Lifshitz theory to derive closed-form expressions for fluctuation correlations in electrolyte solutions, indicating significantly different decorrelation processes of ionic concentration fluctuations from hydrodynamic fluctuations, which provides insights for understanding transport phenomena of coupled fluctuating hydrodynamics and electrokinetics. Furthermore, we simulate fluctuating electrokinetic systems using both molecular dynamics (MD) with explicit ions and mesoscopic charged dissipative particle dynamics (cDPD) with semi-implicit ions, from which we identify that the spatial probability density functions of local charge density follow a gamma distribution at sub-nanometre scale (i.e. ), indicating the existence of a lower limit of length scale for mesoscale models using Gaussian fluctuations. The temporal correlation functions of both hydrodynamic and electrokinetic fluctuations are computed from all-atom MD and mesoscale cDPD simulations, showing good agreement with the theoretical predictions based on the linearized fluctuating hydrodynamics theory.
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影响因子：
2.7
作者：
D. Ladiges;A. Nonaka;Katherine Klymko;G. C. Moore;J. Bell;S. Carney;Alejandro L. Garcia;S. Natesh;A. Donev
通讯作者：
D. Ladiges;A. Nonaka;Katherine Klymko;G. C. Moore;J. Bell;S. Carney;Alejandro L. Garcia;S. Natesh;A. Donev
波动、响应和松弛：重新审视线性响应理论
影响因子：
2.2
作者：
R. Kubo
通讯作者：
R. Kubo
影响因子：
4.4
作者：
Kim, Changho;Nonaka, Andy;Donev, Aleksandar
通讯作者：
Donev, Aleksandar
影响因子：
2.6
作者：
Galindres, Diana M.;Eslava, Valeria J.;Leaist, Derek G.
通讯作者：
Leaist, Derek G.
影响因子：
--
作者：
BERENDSEN, HJC;GRIGERA, JR;STRAATSMA, TP
通讯作者：
STRAATSMA, TP