Hysteresis full model

The model proposed by Zsigmondy—which in broad terms is still accepted to-day—assumed that along the initial part of the isotherm (ABC of Fig. 3.1), adsorption is restricted to a thin layer on the walls, until at D (the inception of the hysteresis loop) capillary condensation commences in the finest pores. As the pressure is progressively increased, wider and wider pores are filled until at the saturation pressure the entire system is full of condensate. 

FONI model (a) unique (b) single hysteresis loop or breaking wave (c) isola (d) isola + hysteresis loop (e) mushroom. With the full Arrhenius rate law and the provision pre-heating or cooling, two additional patterns are found (f) reversed hysteresis loop and (g) reversed hysteresis loop + isola. Also shown are various degenerate loci corresponding to parameter values on the boundaries or special points in the parameter plane (see Fig. 7.5). 

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