Chapter 4 - Aspects of Particle Adhesion and Removal

Abstract

This chapter describes the forces, interactions, and factors that control the adhesion and cohesion of particles. It also discusses how the adhesion of particles to surfaces is commonly determined. Forces of nature are generally categorized as one of four types: strong interactions, weak interactions, electromagnetic interactions, and gravitational interactions. Which of these are important in a given instance depends on the size of the particles and the separations between the particles or between the particles and the substrates. Particles adhere to surfaces because of both the existence of attractive forces between the particles and the substrates and the mechanical responses of these materials to these attractive forces. Specifically, the interactions between a particle and a contacting substrate cause stresses in both materials. These stresses cause the materials to deform and it is the combination of the deformation and the strength of the interactions that determines how strongly a particle is bonded to a substrate. This discussion concludes that the choice of the means of cleaning must consider the particle-substrate interactions as well as the process speeds.