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Water and methanol vapor adsorption isotherms for native and modified potato starch were investigated. For obtaining the best fit for the experimental data several models based on the BET approach was evaluated. The hypothesis that water is adsorbed on the starch granules at the primary and secondary adsorption sites as well as a concept considering the adsorbent fractality were also tested. It was found, that the equilibrium adsorption points in the examined range of relative humidity (0.03-0.90) were most accurately predicted by using a three-parameter model, proposed by Kats and Kutarov (1998). For methanol a good representation of experimental data was obtained using model proposed by Talu and Meunier (1996).

The results of studies on new precursors for the preparation of gallium nitride and aluminium nitride were presented. The samples obtained were characterised by argon adsorption at 77 K. The variation of the porous structure parameters with the pyrolysis temperature was discussed. The adsorption of water vapour and the selectivity of adsorption with respect to some gases at 298 K were also investigated.

Of the various gas/solid adsorption processes, the adsorption of methanol on active carbon seems to be most interesting for use in thermodynamic systems such as heat pumps and transformers, as well as in cooling systems. The porous structures of two series of active carbons modified by the successive removal of the external layers from the particle surface, one by abrasion in a spouted bed and the other by subsequent demineralization of the abraded particles, were evaluated on the basis of nitrogen and methanol adsorption data. The porous structure parameters for these two sorbate series agreed reasonably well and allowed the D-R approach to be usefully applied for the characterization of these systems. The methods for calculating the heat effects associated with methanol adsorption over wide ranges of temperature and pressure are discussed.

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