Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Caixa Postal 6165, 13083-970, Campinas, São Paulo, Brazil.
J Phys Chem B. 2010 Mar 18;114(10):3583-91. doi: 10.1021/jp911898t.
We obtain the electrostatic free energy of finite-sized ions near a dielectric interface within the framework of the classical continuum dielectric theory. The ion is modeled as a dielectric sphere with a fixed uniform surface charge density. In order to avoid the generation of additional induced charges on the ionic surface, it is assumed there is no dielectric contrast between the ion core and the external dielectric medium where it is embedded, which allows an exact solution of the electrostatic problem by the image-charge method. It is shown that earlier results reported in the literature, especially when there is partial ionic penetration into the interface, always underestimate the electrostatic free energy associated with nonpolarizable ions. For an ion modeled as a vacuum cavity at the water-vapor interface, it is estimated that the free energy is an order of magnitude larger than prior predictions.
我们在经典连续介电理论的框架内获得了介电界面附近有限大小离子的静电自由能。离子被建模为具有固定均匀表面电荷密度的介电球体。为了避免在离子表面上产生额外的感应电荷，假设离子核与嵌入的外部介电介质之间没有介电对比度，这允许通过镜像电荷方法对静电问题进行精确求解。结果表明，文献中报告的早期结果，特别是当离子部分穿透界面时，总是低估了与不可极化离子相关的静电自由能。对于在水汽界面处建模为真空腔的离子，估计其自由能比之前的预测大一个数量级。
