Recent developments in immersion calorimetry.

The two calorimetric methods of determination of the enthalpies of immersion and of wetting are described in this text. The equations linking the adsorption enthalpies to the immersion enthalpies and to the wetting enthalpies are derived. Three experimental examples are shortly described in order to give the experimental limits and ability of these techniques. In the second part, a general model for the interpretation of adsorption and wetting is developed. This model uses three parameters related to the dispersive, acid and basic components of the energy. Some experimental examples are given, in order to show that it is possible to compute the surface energy of divided solids. From these results, it is also possible to predict the macroscopic behaviour of these solids when facing pure fluids. (C) Academie des sciences/Elsevier, Paris.