Electrophoresis of Micro/Nano Gels

Electrophoretic mobility measurements serve as a powerful technique for probing the surface electrical properties of colloidal particles dispersed in electrolyte solutions. While the electrophoretic mobility is commonly converted into the zeta potential for rigid particles, this approach becomes inadequate for soft particles, such as those coated with polyelectrolyte layers. In such cases, the Donnan potential within the ion-permeable polyelectrolyte layer offers a more appropriate physical interpretation. This article outlines the theoretical framework for understanding the electrophoretic mobility of soft particles, with a particular focus on gel particles, which are typical examples of such systems. We consider a general model in which a gel particle comprises a solid core surrounded by a polyelectrolyte layer. The case of gel particles without a core, corresponding to spherical polyelectrolytes, is also discussed. This work provides a theoretical foundation for analyzing electrophoretic behavior in soft colloidal systems.