On the problem of the determination of the adsorption phase thickness for the adsorption of solutions on macroporous adsorbents

A system of equations previously obtained from the Ono-Kondo model for desc ribing the excess adsorption isotherms for the adsorption of the components of solutions on macroporous adsorbents is used to calculate the compositio n of the first two layers of the adsorbate. It is shown that, for most syst ems for which the dimensionless exchange energy calculated from the heats o f evaporation of the pure components of the solution is smaller than 0.04, the composition of the second layer does not differ from that of the bulk p hase; therefore, when passing to the method of total content, it is possibl e to consider the adsorption phase as a monolayer. Only for a limited numbe r of systems, a treatment of the second layer is required. The results obta ined are in close agreement with the results of thermodynamic calculations by the Larionov method.