1959 年 79 巻 1 号 p. 64-65
A method was found by which the value of wetting heat is calculated graphically from adsorption isotherm, using the change of Gibbs' free energy in adsorption. Prior absorption of moisture by a tablet decreases generation of wetting heat. In the above method, wetting heat generated by a sample which has absorbed moisture can be calculated by integration on the graph eliminating the primary moisture. In one example of aluminum silicate sample, a presence of a slight moisture resulted in marked decrease of wetting heat. This is due to the type of adsorption isotherm and it should be clear from Fig. 1 that the substances indicating adsorption isotherm of BET II-and IV-types show marked decrease of wetting heat by initial moisture.