Intermolecular Forces Responsible for Adhesion

In this section, I will briefly discuss (1) intermolecular forces responsible for adhesion (2) mechanisms of adhesion molecular contact at the interface, molecular configuration and conformation (3) wetting and thermodynamic equilibrium (4) bond character and adhesive performance (5) the role of diffusion (6) the electrostatic contribution and (7) the locus of adhesive failures. 

Understanding the intermolecular forces responsible for adhesion and cohesion is quite important. The elastic constants, the plastic deformation, the presence of flaws are functions of inter- and intramolecular forces and steric hindrances to rotation in the various molecules. It is important to relate the magnitude of intermolecular forces between molecular species and a particular substrate to the relative adhesive strengths. 

Predictions based solely on intermolecular forces do not always agree with experiment, and other factors such as deformation behaviour and wetting must be considered. The amorphous fraction of polymers used for adhesion is free to conform to the structure of the substrate [33]. 

The net force F (note that F = —dU/dl, where I is the distance) is given by 

A pure ionic bond is one in tvhich a positive and a negative ion attract each other, and the energy of interaction t/ionic is 

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