Abstract
We examine the adsorption hysteresis for the multilayer adsorption with a hysteresis loop of the type H1 according to the IUPAC classification. To describe the adsorption branch of the hysteresis loop, the Frenkel – Halsey – Hill (FHH) equation has been used. The equation of the desorption branch of the hysteresis loop was obtained on the basis of joint solutions of the equation for the change in the Gibbs free energy function (taking into account the connectivity of pores) and the Laplace equation, written for the conditions of infinitely extended meniscus. The resulting equation was tested with the example of the nitrogen
adsorption isotherm on the silica Davisil.
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