Thermodynamics of Adhesion

Abstract

Although practical adhesion depends on more than just interfacial bonds, clearly the latter are fundamental: the stronger the links, the higher the adhesion. In many cases, interfacial bonding is of a physical nature, and is closely akin to wetting, with the same types of physical phenomena occurring. These can be treated from a thermodynamic standpoint. Wetting data may be used to estimate the thermodynamic, or Dupré, energy of adhesion, provided certain assumptions are made and suitable models constructed for, in particular, interfacial tensions. Several models have been established with greater or lesser success. The main ones are reviewed here, underlining their essential assumptions.

Introduction

As measured by mechanical tests, adhesion strength is usually not a reversible thermodynamic quantity. This is due to various factors, but mainly related to the dissipation of energy connected with the irreversible process of separation. The act