Abstract
Equilibrium and nonequilibrium freezing behaviours of water in polymer gels were inves-tigated by DSC (differential scanning calorimetry). Ice crystallisation during rewarming, observed with the gels frozen under the nonequilibrium condition, i.e., frozen after the substantial undercooling, disappeared when observed with the gels frozen under the equilibrium condition which was induced by the addition of ice nucleating protein. Although ice crystallisation may proceed rather slowly under the equilibrium condition, most of the compartmentalised water crystallises without being vitrified. The different freezing behaviour depending on the freezing condition can be attributed to the different rate of ice crystal growth relative to that of the change in the polymer network.
