Abstract
Phase transfers between the water and ice are a fundamental phenomenon in the cryobiology and
cryotechnology. In order to gain insight into the systems in which ice coexists, we investigated
time–temperature profiles during the freezing and thawing behaviors of aqueous solutions by a
thermal arrest (TA) measurement under stirring. As a result, in addition to freezing point, Tf, an
another characteristic temperature, Td, a deviating point where the experimental and calculated two
profiles departed from each other, was noted in the both freezing and thawing processes. The
constant Td/Tf ratios were obtained in the range from 1.43 to 1.53 for aqueous solutions of NaCl,
KCl, and ethylene glycol (EG). At temperature between Tf and Td, ice grains were well-dispersed
in the solution and no interference of their crystal growth or thawing occurred among ice species.
By contrast, at temperatures below Td, ice grains tended to contact each other, likely inducing the
thermophysical properties of the system to deviate from those at temperatures between Tf and Td.
These results suggest that Td can be an important parameter to define systems in which ice coexists
depending on the initial solution concentration under some specific experimental conditions.
