Experimental procedures to characterize acid—base and dispersion force contributions to solid wettability A review

Abstract

The quantitative characterization of intermolecular interactions across interfaces is of importance in issues such as composites, adhesives and coatings. The interactions being considered here are relatively weak compared to intramolecular bonds but are very important in establishing desired properties in such materials. Of greatest significance are the van der Waals (especially the London dispersion) forces and the Lewis acid—base, including hydrogen bond, forces. This paper will review recent advances in techniques for measuring the capability of various surfaces to form interfacial bonds based on dispersion force and acid—base attractions, that is, measuring wettability of solids by various materials such as liquids, adhesives and coating resins. The techniques to be reviewed are contact angle measurement, calorimetry, spectral shift measurement and inverse gas chromatography. Strengths of acidic and basic sites on the surface are expressed quantitatively as solid surface tension, work of adhesion and enthalpy of bond formation (Drago E and C constants; Gutmann acceptor and donor numbers).