Smagala Thomas G, Fawcett W Ronald
Department of Chemistry, University of California, Davis, California 95616, USA.
J Phys Chem B. 2007 Nov 15;111(45):13075-81. doi: 10.1021/jp073868l.
The theory of the diffuse layer for asymmetric electrolytes is reconsidered with emphasis on the effects of ion size on the diffuse layer potential drop and differential capacity. For asymmetric 2:1 and 1:2 electrolytes, this potential drop is expressed in terms of a polynomial with a linear, quadratic, and cubic term in the corresponding estimate in the Gouy-Chapman theory. Optimal polynomial coefficients and model validation for 2:1 electrolytes are provided by least-squares regression of Monte Carlo data obtained for a restricted electrolyte in a primitive solvent. These coefficients are then expressed as simple functions of the parameters commonly associated with the mean spherical approximation. The series approach accurately describes potential drops and differential capacities of the diffuse layer for 2:1 and 1:2 electrolytes for the chosen assumptions.
重新审视了不对称电解质的扩散层理论，重点关注离子大小对扩散层电势降和微分电容的影响。对于不对称的2:1和1:2电解质，该电势降用多项式表示，该多项式在古依-查普曼理论的相应估计中有线性、二次和三次项。通过对在原始溶剂中受限电解质获得的蒙特卡罗数据进行最小二乘回归，提供了2:1电解质的最佳多项式系数和模型验证。然后将这些系数表示为通常与平均球近似相关的参数的简单函数。对于所选假设，该级数方法准确地描述了2:1和1:2电解质扩散层的电势降和微分电容。
