SOME FUNDAMENTAL ISSUES IN ADHESION - A CONCEPTUAL VIEW

The role of interfacial interactions in determining the global respons e of joint systems is discussed in relation to the question of true in terfacial failure and the ubiquitous occurrence of interphases. The di scussion is from the point of view of systems involving adhesives, coa tings and composites rather than, e.g., particle-particle or particle- substrate systems and is strictly conceptual in nature. It is proposed that interfacial interactions, rather than directly exerting an effec t on the global response of joint systems, are instead the driving for ce for the many and varied processes that create interphases. It is su ch interphases, or transition zones between phases, which affect the g lobal mechanical response of joint systems.