Ogawa Shigesaburo, Osanai Shuichi
Department of Applied Chemistry, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku, Yokohama 223-8522, Japan.
Cryobiology. 2007 Apr;54(2):173-80. doi: 10.1016/j.cryobiol.2007.01.005. Epub 2007 Jan 30.
DSC and simultaneous XRD-DSC measurements were carried out to clarify the interaction among the ingredients in a ternary aqueous solution composed of NaCl, a sugar-based amphiphile or free sugar, and water. Two aspects of the inhibition of eutectic formation were suggested through the addition of the sugar amphiphile. One was the retention of the glass state of the eutectic phase, and the other was the trapping of NaCl hydrate into the sugar moiety of the amphiphilic aggregate. The difference between the free sugar and the amphiphilic one in terms of the trapping of NaCl hydrate was attributable to their dissimilarity in the dissolution state. The results indicated that the free sugars in water could interact with NaCl hydrate on the basis of their various hydroxyl groups. On the other hand, the sugar-based amphiphiles generated a self-assembly aggregate in the system, and interacted with NaCl hydrate by a salting-in effect with their sugar moiety in the freezing-thawing process. It was confirmed that the number of sugar units played an important role in trapping NaCl hydrate in the system. The effects of the structural isomerism in the sugars were slight with regard to the inhibition of eutectic formation.
进行了差示扫描量热法（DSC）和同步X射线衍射-差示扫描量热法（XRD-DSC）测量，以阐明由氯化钠、糖基两亲物或游离糖与水组成的三元水溶液中各成分之间的相互作用。通过添加糖基两亲物，提出了抑制共晶形成的两个方面。一是共晶相玻璃态的保留，另一个是氯化钠水合物被困在两亲性聚集体的糖部分中。游离糖和两亲性糖在捕获氯化钠水合物方面的差异归因于它们溶解状态的不同。结果表明，水中的游离糖可以基于其各种羟基与氯化钠水合物相互作用。另一方面，糖基两亲物在体系中形成自组装聚集体，并在冻融过程中通过其糖部分的盐溶效应与氯化钠水合物相互作用。证实了糖单元的数量在捕获体系中的氯化钠水合物方面起着重要作用。糖的结构异构对共晶形成的抑制作用较小。
