Heat Capacity and Heat Conductivity of Aqueous Solutions of Calcium Chloride in Silica Gel Pores
Russian Journal of Physical Chemistry A
, E-ISSN: 1531-863X
Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences, pr. akademika Lavrent'eva 5, Novosibirsk, 630090, Russian Federation
Ist. Trasformazione Accumulazione E., Messina, 98126, Italy
The heat capacity and heat conductivity of the CaCl2-H2O system in pores of KSKG silica gel were studied. The heat capacity was calorimetrically determined as a function of temperature (308-378 K) and water content (weight fraction 0-0.3). Analytical expressions describing these dependences were obtained. The heat capacity of the material can satisfactorily be represented as the sum of the heat capacities of the components. The heat conductivity was measured by the "hot wire" method for water contents in the range w = 0.35-0.75 at temperatures t = 20-23°C. At low water contents (w < 0.4), the heat conductivity changed insignificantly, from 0.33 to 0.36 W/(m K). Increasing w above 0.4 resulted in a rapid growth of the heat conductivity to 0.5-0.55 W/(m K). It was found that dispersing the CaCl2-H2O system in silica gel pores had only a weak effect on the heat capacity and conductivity of the material.