ESTIMATION OF THE POLAR SURFACE TENSION PARAMETERS OF GLYCEROL AND FORMAMIDE, FOR USE IN CONTACT ANGLE MEASUREMENTS ON POLAR SOLIDS

ABSTRACT By measuring contact angles with water, glycerol and formamide on a number of polar surfaces, an estimate could be made of the electron-acceptor (γ+ ) and the electron-donor (γ− ) parameters of glycerol (G) and formamide (F), relative to the parameters of. water (W), for which a reference value of γ+ W = γ− W = 25.5 mJ/m2 has been assumed. The values thus found are: γ+ G ≈ 3.92 mJ/m2 (which yields γ− G ≈ 57.4 mJ/m2) and γ+ F ≈2.28 mJ/m2 (which yields γ− F ≈ 39.6 mJ/m2).