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Abstract: Ternary system: H2O–Fe(NO3)3–Co(NO3)2 isotherm: 30 °C. The H2O–Co(NO3)2 binary system has been investigated in the –28 to 50 °C temperature range. The solid–liquid equilibria of the ternary system H2O–Fe(NO3)3–Co(NO3)2 were studied by using a synthetic method based on conductivity measurements. One isotherm is established at 30 °C, and the stable solid phases that appear are iron nitrate nonahydrate: Fe(NO3)3·9H2O, iron nitrate hexahydrate: Fe(NO3)3·6H2O, cobalt nitrate hexahydrate: Co(NO3)2·6H2O, and cobalt nitrate trihydrate: Co(NO3)2·3H2O. To cite this article: B. El Goundali et M. Kaddami, C. R. Chimie 9 (2006) . [Copyright &y& Elsevier]

Pressure–volume isotherms have been determined for three heterogeneous ‘water–zeolite’ systems. The first two concern hydrophobic purely siliceous zeolites: silicalite-1 (F−) and zeolite β (F−); the third comprises a more hydrophilic commercial zeolite of the type ZSM-5. The P–V diagram for the water–silicalite-1 (F−) system is characterized by a plateau corresponding to the intrusion of water inside the pores of the solid. During the release the phenomenon is reversible. This system, which is able to accumulate and restore superficial energy, constitutes a molecular spring. For zeolite β, the P–V curve displays a plateau during the compression, but during the release, the phenomenon is not reversible. In that case, the system absorbs mechanical energy and acts as a bumper. The third system, based on the more hydrophilic ZSM-5 zeolite shows a linear isotherm without any plateau. These results open new applications perspectives in the field of the energetics for hydrophobic zeolites in contact with water. To cite this article: V. Eroshenko et al., C. R. Physique 3 (2002) 111–119 [Copyright &y& Elsevier]