MgSO4/alumna] were synthesized. The sorption equilibrium of these sorbents with water vapor was studied at
pressures from 10 to 50 mbar and temperatures from 20 to 300
. It was established that the sorption equilib-rium and phase composition of Mg, Na, and Cu sulfates dispersed into pores of KSK silica gel are determined
by the concentration of the salt in the composite. At low concentrations of the salt, it exists in the pores in the
form of an XRD-amorphous phase, whose composition changes monotonically with the water vapor pressure
and the temperature (bivariant system). In the pores of systems containing high concentrations of Mg and Na
sulfates, a crystalline phase of the salt is formed. The dispersity of this phase is determined by the size of the
pores in silica gel, 10–25 nm. The sorption of water vapor by these systems is accompanied by the formation
of a salt crystal hydrate with a fixed composition (univariant systems). As the sorption of water vapor proceeds
still further, a salt solution is formed in the pores, and the system becomes bivariant. Depending on the nature
of the salt, the crystalline phase is formed at a salt concentration of 15 to 25 wt %. The characteristics of the
sorption of water vapor by dispersed sulfates were compared with those reported for Ca and Li halides dispersed
in the same matrices.