Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
Langmuir. 2010 Dec 7;26(23):18016-9. doi: 10.1021/la1035745. Epub 2010 Nov 3.
When the electrophoretic mobility of a particle in an electrolyte solution is measured, the obtained electrophoretic mobility values are usually converted to the particle zeta potential with the help of a proper relationship between the electrophoretic mobility and the zeta potential. For a particle with constant surface charge density, however, the surface charge density should be a more characteristic quantity than the zeta potential because for such particles the zeta potential is not a constant quantity but depends on the electrolyte concentration. In this article, a systematic method that does not require numerical computer calculation is proposed to determine the surface charge density of a spherical colloidal particle on the basis of the particle electrophoretic mobility data. This method is based on two analytical equations, that is, the relationship between the electrophoretic mobility and zeta potential of the particle and the relationship between the zeta potential and surface charge density of the particle. The measured mobility values are analyzed with these two equations. As an example, the present method is applied to electrophoretic mobility data on gold nanoparticles (Agnihotri, S. M.; Ohshima, H.; Terada, H.; Tomoda, K.; Makino, K. Langmuir 2009, 25, 4804).
当测量电解质溶液中颗粒的电泳迁移率时，通常借助电泳迁移率和zeta 电位之间的适当关系，将获得的电泳迁移率值转换为颗粒的 zeta 电位。然而，对于具有恒定表面电荷密度的颗粒，表面电荷密度应该是比 zeta 电位更具特征的量，因为对于这种颗粒，zeta 电位不是一个常数，而是取决于电解质浓度。本文提出了一种不需要数值计算机计算的系统方法，基于颗粒电泳迁移率数据来确定球形胶体颗粒的表面电荷密度。该方法基于两个解析方程，即颗粒电泳迁移率和 zeta 电位的关系以及颗粒 zeta 电位和表面电荷密度的关系。使用这两个方程对测量的迁移率值进行分析。作为一个例子，本方法应用于金纳米颗粒（Agnihotri，SM；Ohshima，H；Terada，H；Tomoda，K；Makino，K. Langmuir 2009，25，4804）的电泳迁移率数据。
