Surface-anchored polymer chains: Their role in adhesion and friction

Polymer surfaces and interfaces have many technological applications. In th e present article we review some recent experiments conducted on model syst ems with the aim of understanding the role played by surface-anchored polym er layers in adhesion and friction. We also discuss some of the related the oretical models. The key parameter for both situations is the degree of int erdigitation between the surface layer and the bulk polymer system tan elas tomer in the case of adhesion, a molten polymer in the case of friction). W e analyze how this degree of interdigitation governs the optimum enhancemen t in the adhesion energy between the solid wall and an elastomer, and how i t is at the origin of the various wall slip regimes observed experimentally .