Experimental determination of spreading pressure in solid/liquid/vapour systems

Abstract

The basic assumption is made that the film pressure, π_e, for the vapours of liquids on polar and non-polar solid surfaces is not negligible. A method is given which allows π_e to be calculated from contact angle and γ_LV measurements. It is based on the fact that the work of adhesion, W_A, has a maximum value when there is no vapour adsorption. This maximum value is, by definition, W_A0. It is demonstrated that the work of adhesion of mercury gives a good estimate of W_A0. Since π_e = W_A0, - W_A, π_e can be obtained easily for any liquid-solid pair

Keywords:

• Film pressure
• work of adhesion
• spreading pressure