液/液界面双电层统计热力学

Abstract

应用系综统计法处理液/液界面双电层体系.根据MVn模型.建立系统的正则及巨正则配分函数,导出系统各热力学量统计平均.拟合计算界面内层构型熵(△S_M)及内层微分电容(C_1)随表面电荷密度(σ--M)变化关系.理论同时表明,C_1与σ--M或△(？)_1(界面内层电势降)的涨落存在确定关系.

The Fundamental of Statistical Thermodynamics For electrical double layer at the interFace between two immiscible electrolyte solution(ITIES) are discussed.According to MVN model,the ITIES was represented by that the two space charge regions are separated by an inner layer of the oriented solvent molecules.Assuming that the ions were allowed to penetrated into the compact solvent layer over some distance, then the grand canonical partition Function of the inner layer at ITIES can be given,in which the mean Field approximation is employed to estimte the interactive patential energy of the system,including the dipole-dipole, dipold-ion and ion-ion interaction.The thermodynamics properties of system,such as inner layer conFiguration entropy (ΔSm), diFFerential capacity(C1) and others For the L/L interFace are derived,and the Fitting curves of the ΔSm/or C1 as a Function of the surFace charge densily (σm) to an image W/O interFace are given.In the grand canonical ensemble theory,the inner layer diFFerential capacity (C1) or which reciprocal capacity (I/C1)can be expressed by the surFace charg Fluctuation/or by the Fluctuation of potential drop (Δψ1) across the inner layer at ITIES.