5. Calorimetric Studies on the Freezing Mechanism of Aqueous Solutions : Freezing of Aqueous Solutions of Tetraalkylammonium Bromide(Synopsis paper presented at the 28th Annual Meeting)

Abstract

Thermal behaviors of water in the aqueous solutions of tetraalkylammonium bromide have been investigated through freezing and thawing processes by using low temperature DSC. Two different types of clathrate hydrates in the aqueous solution of tetrabutylammonium bromide were observed at 12℃ and 18℃ respectively by calorimetric method. In the solutions of tetramethyl, and tetraethylammonium bromide, formation of eutectic mixtures was observed at -13℃ and -22℃, respectively. They are independent of the concentration of solutes. Roles of molecular space in the aqueous solutions were discussed in relation to freezing of solutions.