低温抗冻剂溶液玻璃化转变的临界冷却速率

生物材料的玻璃化低温保存技术已受到广泛注意。本文修正了Foutron的半经验结晶动力学模型,并用由此得到的解析表达式,构造各种浓度溶液在等温转变时的温度-时间-转变(TTT)曲线和变温转变时的连续-冷却-转变(CCT)曲线,预测实现玻璃化转变所需的最小冷却速率,以反映溶液玻璃化形成倾向的大小。结果表明,丙二醇的玻璃化形成倾向大于乙二醇和甘油。若在丙二醇溶液中加入丁二醇,可进一步提高其玻璃化形成能力。

THE CRITICAL COOLING RATES FOR VITRIFICATION OF CRYOPROTECTIVE SOLUTIONS

In order to avoid the damage effects of ice formation during freezing, the vitrification technique for cryopreservation of the biological materials has arrested much public attention recently. In this paper, a semi-empirical model developed by Boutron has been modified. The exact analytical expressions obtained here can be used to construct those temperature-time-transformation(TTT)curves for isothermal crystalli- zation and continuous-cooling-transformation (CCT)curves for nonisothermal crystallization, from which the critical cooling rates required for vitrification of cryoprotective solutions can then be predicted directly. It is found that the glass-forming tendency of 1, 2-propanediol is higher than ethylere glycol and glycerol, the critical cooling rates can be reduced by adding 1,2-butanediol into 1,2-propanediol solution.