Thermodynamic Properties of Adsorbed Water Molecules and Electrical Conduction in Montmorillonites and Silicas

Abstract

The relation between some electrical properties and thermodynamic properties of adsorbed water has been studied for two montmorillonites, a silica gel, and a window glass powder at room temperature. A relationship has been found between electrical conduction and the mobility of water molecules in the monolayer. These molecules are immobile on the hydroxylic surface of silica gel and mobile on the oxygen internal surface of montmorillonite. The electrical conduction in the monolayer is believed to be mainly protonic. The dissociation degree of water molecules in this situation seems to be of the order of magnitude of 1%.

Ionic Migration and Weathering in Frozen Antarctic Soils

“…to contrast ionic migration in a slightly saline, coarse textured and shallow depth to the ice-cemented permafrost soil, with that in a saline, fine textured and deeper soil; 2. an experiment duration of two years or more; 3. to compare and contrast the movement of the positive (Na 22 ) ion with that of (Cl 36 ) observed in the preceding study.…”

“…To confirm these results and to gain additional insight into the migration process, during austral summer of 1969, 20 pc of Na 22 Cl were placed at the top of the ice-cemented permafrost at three sites. The area chosen for this experiment was in the lower Wright Valley on the morainic complex of the Trilogy glaciation near the earlier Cl 36 site (Fig.…”

“…With the exception of the samples next to the source, no activity (after correction for background) was recorded at any depth down to within 5-10 cm of the initial location of the radioactive NaCl introduced. Because of the sampling increments employed, (see Table 1), it is possible that the Na 22 The physical and chemical parameters of profiles 5 and 7 (Table 1) have characteristics typical of soils in the lower Wright valley (2).…”

“…The labeled Na added in the NaCl form might be adsorbed on the exchangeable sites or it might remain in the interparticle spaces as a free salt. Wherever the Na 22 is located, on the exchangeable sites or in solution, because of the extremely dry and below freezing conditions, the migration of these ions is limited to movement in the thin films of unfrozen water. At the tem- (19).…”

Investigations on humidity sensing of nanostructured tin oxide synthesisedviamechanochemical method

“…The condensation of water vapours occurs as a function of semiconducting pore size and its distribution. The variations observed in humidity measurements in semiconducting sensors originated by the chemical and physical adsorption of water molecules existing in the atmosphere [35][36][37]. Therefore, the presence of large pores is considered as the achievement of high-humidity sensing for sensing materials [38].…”