Analytical dispersion force calculations for nontraditional geometries

Presented in this paper are first-principle-based approximate macroscopic m odels of the van der Waals adhesion force for a variety of particle shapes interacting with an infinite cylinder. In particular, expressions for the v an der Waals adhesion force and interaction energy are developed for a (1) spherical particle/infinite cylinder, (2) disk-like particle/infinite cylin der, (3) disk-like particle oriented edgewise to an infinite cylinder, and (4) a deformed slice/infinite cylinder. The models presented depict expecte d trends in the behavior of both the force of adhesion and the interaction energy between different geometric configurations. These results are also u sed to demonstrate the impact of contact time on the adhesion force for cyl indrical fibers in contact with a disk-shaped particle. After long time int ervals where the disk-like particles have remained in contact with the cyli nder, the adhesion force may lead to significant deformation of the attache d particle. Hence, the adhesion force for a fourth geometric set which repr esents the most likely scenario for attached particles with long contact ti mes is developed. As will be shown, this scenario results in the highest va lues of adhesion force and interaction energy. (C) 2000 Academic Press.