论文标题
电解质理论，包括空间，有吸引力和水合相互作用的理论
Theory of electrolytes including steric, attractive, and hydration interactions
论文作者
论文摘要
我们提出了由水样溶剂和单价离子组成的电解质的连续理论。首先，我们从密度功能$ \ cal f $开始，用于粗粒溶剂，阳离子和阴离子密度，包括Debye-Hückel自由能，库仑相互作用以及这三个组件之间的直接相互作用。这些密度波动，遵守分布$ \ propto \ exp（ - {\ cal f}/k_bt）$。消除了$ \ cal f $中的溶剂密度偏差，我们获得了离子之间的有效非鸡相互作用，这些相互作用由直接介导的离子和溶剂介导的离子组成。 ％以离子量％为单位，与溶剂可压缩性成反比。然后，我们得出离子相关性，明显部分体积以及活性和渗透系数的一般表达式，直至平均盐密度$ n _ {\ rm S} $的线性顺序。其次，我们使用Mansoori-Carnahan-Starling-Lenland Model $ [$ J。化学物理。 {\ bf 54}，1523（1971）$] $，用于三个组件硬透明。有效的相互作用敏感地取决于阳离子和阴离子的大小，这是由于空间和水合效应之间的竞争，这些效应在小型离子对之间具有排斥性和在对称对之间的吸引力。这些与以前的实验和Collins的规则$ [$ Biophys一致。 J. {\ bf 72}，65（1997）$] $。我们还提供了对任何离子大小有效的离子相互作用系数的简单近似表达式。
We present a continuum theory of electrolytes composed of a waterlike solvent and univalent ions. First, we start with a density functional $\cal F$ for the coarse-grained solvent, cation, and anion densities, including the Debye-Hückel free energy, the Coulombic interaction, and the direct interactions among these three components. These densities fluctuate obeying the distribution $\propto \exp(- {\cal F}/k_BT)$. Eliminating the solvent density deviation in $\cal F$, we obtain the effective non-Coulombic interactions among the ions, which consist of the direct ones and the solvent-mediated ones. %where the latter are written in terms of the ion volumes %and are inversely proportional to the solvent compressibility. We then derive general expressions for the ion correlation, the apparent partial volume, and the activity and osmotic coefficients up to linear order in the average salt density $n_{\rm s}$. Secondly, we perform numerical analysis using the Mansoori-Carnahan-Starling-Leland model $[$J. Chem. Phys. {\bf 54}, 1523 (1971)$]$ for three-component hardspheres. The effective interactions sensitively depend on the cation and anion sizes due to competition between the steric and hydration effects, which are repulsive between small-large ion pairs and attractive between symmetric pairs. These agree with previous experiments and Collins' rule $[$Biophys. J. {\bf 72}, 65 (1997)$]$. We also give simple approximate expressions for the ionic interaction coefficients valid for any ion sizes.
