Theory of Adhesion of Small Particles

A theory of adhesion between small solid particles and a solid wall is presented which is based on van der Waals forces of attraction between the adherents causing irreversible deformations at their interface. The van der Waals constant is calculated from the imaginary parts of the frequency-dependent dielectric constants of the adherents. While the van der Waals constant of any pair of materials ranges, probably, between 0.5 and 9 eV, forces of particle adhesion at a given particle radius extend over several orders of magnitude owing to large variations in deformability and geometry of the interface between the adherents. Qualitatively, the results agree with experiment. The contributions of electrostatic forces to particle adhesion are estimated.