Contact-mechanics-based studies of adhesion between polymers

Contact mechanics deals with the deformation of solid bodies in contact. In recent years, significant advances have been made both in the theoretical and experimental areas of contact mechanics, especially in the area of soft solids, in relating the contact deformation to interfacial adhesion. On the theoretical front, new theories of contact mechanics have been developed to relate the interfacial force induced deformation to the thermodynamic work of adhesion both for elastic and viscoelastic solids. On the experimental front, several new techniques have been developed to measure the interfacial forces and the interfacial-force-induced deformations. These techniques have been used, with the aid of the theories of contact mechanics, to measure directly the surface and interfacial energies of a. variety of polymers and other model surfaces. These experimental and theoretical developments have also been exploited to measure quantitatively the effect of interfacial chain diffusion on the adhesion of polymer inter-faces. We summarize the recent developments in the theories of contact mechanics, and their applications in the design and interpretation of experimental measurement of molecular level adhesion between elastomers, glassy and viscoelastic polymers. We also review the experimental and theoretical developments related to the role of chain diffusion on interfacial adhesion. Finally, we identify some potential new applications of contact-mechanics-based techniques in such emerging area of adhesion science as molecular level studies of adhesion of viscoelastic materials and biomaterials.