disjoining pressure (for the attraction between two surfaces)

https://doi.org/10.1351/goldbook.D01790
The force \(\mathit{\Pi} _{\text{d}}\) per unit area which can be obtained as the derivative of \(-g_{\text{t}}\) with respect to the distance, where \(g_{\text{t}}\) is the total Gibbs energy of interaction per unit area of each of the two flat and parallel plates.
Source:
PAC, 1972, 31, 577. (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 616 [Terms] [Paper]