Donor-Acceptor Interactions at Interfaces

Abstract The free energy change per unit area on separating an interface (the work of adhesion, WA ) is composed of a variety of interactions: where superscripts are d for London dispersion forces, h for hydrogen-bonding, ab for acid-base interaction, p for dipole-dipole interaction, and i for induced dipole-dipole interaction. The work of cohesion can be similarly separated into components of surface tension(γ d , γ h , γ ab , γ p , γ i ).The success of predicting WA d by 2√γ1 d γ2 d , as derived from London force theory, has led others to propose that WA h = 2√γ1 h γ2 h , etc. However, there is no theoretical basis for the latter and we see that present experimental data indicate rather clearly that at a solid-liquid interface WA h is directly proportional to γ L h :