ON THE DESCRIPTION OF THE ADHESIVE CONTACT OF SPHERES WITH ARBITRARY INTERACTION POTENTIALS

We have generalized the Maugis model of the adhesive contact of sphere s (Maugis D., J. Colloid Interface Sci. 150, 243, 1992) to arbitrary i nteractions in two different ways. On the one hand, if we choose an ar bitrary interaction potential between surfaces, we obtain an exact for mulation of the problem, which unfortunately requires computationally demanding numerical solutions, On the other hand, if we prescribe the stress distribution outside the contact zone, we can build numerically efficient approximations which completely describe the contact proble m for a given monotonic attractive interaction with reasonable accurac y. These approximate models retain the simplicity of the Maugis model and may therefore prove useful in data analysis. Our results show that the nature of the interaction has a very moderate influence on the so lution, so that the Maugis model can be used to describe the contact o f spheres with most physically acceptable interaction potentials, exce pt when large accuracy is required. (C) 1998 Academic Press.