Importance of the porous structure of a soft particle on its electrophoretic behavior

The importance of the porous structure of a soft particle comprising a rigid core and a porous layer on its electrophoretic behavior is investigated. The porous layer is simulated by an aggregate of primary units, rendering it to have a radially varying fixed charge and hydrodynamic resistance. Key factors, including the thickness of double layer, the linear size of a primary unit, the aggregate dimension, and the thickness and the fixed charge density of the porous layer, are examined for their influence on the mobility of a particle. We show that if the fixed charge density is fixed, then the mobility increases with increasing double layer thickness, and the mobility increases with increasing fixed charge density. Increasing the linear size of a primary unit raises appreciably the mobility. In addition, the mobility increases with increasing thickness or aggregate dimension of the porous layer. The structure of the porous layer of a particle affects most significantly its mobility when the double layer is thick.