A theoretical exploration of the influencing factors for surface potential  

作　　者：刘新敏 杨刚 李航 田锐 李睿 丁武泉 袁若 

机构地区：[1]Chongqing Key Laboratory of Soil Multi-scale Interfacial Process,College of Resources and Environment,Southwest University [2]School of Chemistry and Chemical Engineering,Southwest University

出　　处：《Chinese Physics B》2015年第6期629-636,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.41371249,41201223,and 41101223);the Fundamental Research Funds for the Central Universities,China(Grant No.XDJK2015C059)

摘　　要：Although it has been widely used to probe the interracial property, dynamics, and reactivity, the surface potential remains intractable for directly being measured, especially for charged particles in aqueous solutions. This paper presents that the surface potential is strongly dependent on the Hofmeister effect, and the theory including ion polarization and ionic correlation shows significant improvement compared with the classical theory. Ion polarization causes a strong Hofmeister effect and further dramatic decrease to surface potential, especially at low concentration; in contrast, ionic correlation that is closely associated with potential decay distance overestimates surface potential and plays an increasing role at higher ionic concentrations. Contributions of ion polarization and ionic correlation are respectively assessed, and a critical point is detected where their contributions can be exactly counteracted. Ionic correlation can be almost neglected at low ionic concentrations, while ion polarization, albeit less important at high concentrations, should be considered across the entire concentration range. The results thus obtained are applicable to other interfacial processes.Although it has been widely used to probe the interracial property, dynamics, and reactivity, the surface potential remains intractable for directly being measured, especially for charged particles in aqueous solutions. This paper presents that the surface potential is strongly dependent on the Hofmeister effect, and the theory including ion polarization and ionic correlation shows significant improvement compared with the classical theory. Ion polarization causes a strong Hofmeister effect and further dramatic decrease to surface potential, especially at low concentration; in contrast, ionic correlation that is closely associated with potential decay distance overestimates surface potential and plays an increasing role at higher ionic concentrations. Contributions of ion polarization and ionic correlation are respectively assessed, and a critical point is detected where their contributions can be exactly counteracted. Ionic correlation can be almost neglected at low ionic concentrations, while ion polarization, albeit less important at high concentrations, should be considered across the entire concentration range. The results thus obtained are applicable to other interfacial processes.

关 键 词：Hofmeister effect ionic activity interfacial process potential distribution 

分 类 号：O485[理学—固体物理]