3409. TOMPKINS, F. C. Adsorption Isotherms for Nonuniform Surfaces. Trans. Faraday Soc., vol. 46, 1950, pp. 580-586; Chem. Abs., vol. 45, 1951, p. 18. With certain restrictions regarding the magnitude of certain entropy changes, 4 well-known isotherms are deduced from variation of heat of adsorption with coverage. If the variation of net heat of adsorption with coverage is known either from theoretical calculations or experimentally from calorimetric measurements, the isotherm can be reasonably well characterized. If the concept of nonuniformity of surfaces is accepted, then the interpretation of transformations of state in adsorbed films on solids must be reconsidered. |