Dielectric Interaction of Particle in Electrophoresis

전기 영동에서의 입자간의 전기력에 의한 상호 작용

When two particles close to each other are in electrophoretic motion, each particle is under the influence of the non-uniform electric field generated by the other particle. Two particles may attract or repel each other due to the dielectric force depending on their positions in the non-uniform electric field. It is shown analytically that two adjusting rigid particles can form an aggregate due to the dielectric interaction. To verify the validity of the theoretical prediction, an experiment is carried out by using a microchannel. In the experiment, AC electric field is used to eliminate cumbersome electroosmotic flow. The experimental result shows that the particles form a chain-like structure, which is typically observed in electro-rheological fluid, due to the dielectric interaction.