Physical adsorption of some hydrocarbons - the two dimensional liquid state

The significant structure theory of hydrocarbons such as methane, ethane, propane, i-butane, and n-butane has been applied to the physical adsorption on the homogeneous surface, occuring in the submonolayer region. The partition function for the two dimensional fluid adsorbed on the surface has been derived by considering the hindered rotation in the adsorbed phase. The properties of the isotherm, isosteric heat, and hindered rotational entropy changes upon adsorption show good agreement with the available data from the literature.