NUMERICAL STUDY OF THE ELECTRICAL DOUBLE-LAYER REPULSION BETWEEN NONPARALLEL CLAY PARTICLES OF FINITE LENGTH

The study presented herein concerns the double-layer repulsive force that exists between clay particles in a clay-water-electrolyte system. The objective is to examine the nature of the double-layer repulsive force between two negatively charged clay particles that are inclined to each other and have finite length. The finite element numerical technique is used first to determine the spatial distribution of the electric potential. The net repulsive force and its location are then evaluated from this known distribution of the potential on the basis of the theory of electrostatics. A systematic parametric study is performed by varying certain dimensionless system variables, particularly to investigate the effect of orientation, surface potential and particle length. It is found that for non-parallel orientation, as the value of inclination and surface potential increase, the repulsive force decreases and its location shifts towards the particle ends that are closer to each other.