నైరూప్య

The surface pressure in solid-liquid-vapor system

Ahmed K.Helmy, Silvia G.de Bussetti, Eladio A.Ferreiro

Four equations containing a term in surface pressure, namely the Gibbs adsorption integral, the Young equation, the equilibrium constant equation and the Fowler-Guggenheim equation are examined with respect to the validity of the values obtained for a solid-liquid-vapor system. It is also shown that many values of surface pressure in the published literature cannot be considered as such. It is shown that for vapor pressures below monolayer coverage, the plot of surface pressure against vapor pressure should be a straight line and the energy of adsorption can be obtained from the slope of the line.