Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, PR China.
Cryobiology. 2011 Jun;62(3):210-7. doi: 10.1016/j.cryobiol.2011.03.005. Epub 2011 Mar 31.
Quantitative analyses of the bound water content in the alcohol aqueous solution and its osmotic behavior should be cryobiologically significant. This paper has presented two applications of the thermogram of the alcohol/water system recorded by differential scanning calorimeter (DSC). Both applications are: (1) generating the quantitative relationship between the bound water content and the solution composition; (2) calculating the osmotic virial coefficients for alcohols. Five alcohols including methanol, ethanol, ethylene glycol, propylene glycol and glycerol are investigated. In the present study, partial binary phase diagrams of these five alcohol solutions are determined in the first place. The bound water contents in these solutions are quantitatively evaluated by three criteria afterwards. In the end, the osmotic virial coefficients for these alcohols are calculated according to the osmotic virial equation. It is turned out that the bound water fraction out of the total water content increases with a rising molality. The ability of the solute to restrict water molecules can be weakened when the solution becomes more concentrated. The results also indicate that propylene glycol should be the strongest "water-blocker" while methanol the weakest one. These findings can deepen our understanding of the cryoprotective properties of the alcohols from the perspectives of their roles in binding free water and promoting the osmotic efflux of cell water.
定量分析醇水溶液中的结合水含量及其渗透行为在 cryobiology 上应该具有重要意义。本文介绍了差示扫描量热仪（DSC）记录的醇/水系统热谱的两种应用。这两种应用是：（1）生成结合水含量与溶液组成之间的定量关系；（2）计算醇的渗透维里系数。研究了甲醇、乙醇、乙二醇、丙二醇和甘油这五种醇。在本研究中，首先确定了这五种醇溶液的部分二元相图。然后，根据三个标准对这些溶液中的结合水含量进行了定量评估。最后，根据渗透维里方程计算了这些醇的渗透维里系数。结果表明，结合水分数随摩尔分数的增加而增加。当溶液变浓时，溶质限制水分子的能力会减弱。结果还表明，丙二醇应该是最强的“水阻断剂”，而甲醇则是最弱的。这些发现可以从结合游离水和促进细胞水渗透流出的角度加深我们对醇的 cryoprotective 性质的理解。
