Abstract: Due to the difference of crystallization temperature and enthalpy for free water and interfacial water during the course of cooling, a series of water-in-oil emulsions were studied experimentally by means of differential scanning calorimetry (DSC). The free water and interfacial water and to measure the time-dependent changes were characterized. From the result can only find one exothermic peak corresponding to the interfacial water at about -40 ℃ when the solubilized water mass fraction 15%. By increasing the amount of the solubilized water to 15%, a new significant exothermic peak is present (at -18 ℃) which is attributed to free water. Both the crystallization temperature of free water and interfacial water are affected by the concentration of solubilized water weekly. The stabilization of the 30%W/O emulsion is decreased with the increase of time placed, and the concentration of interfacial water is also reduced. The peak for the crystallization of interfacial water can not found in the DSC thermogram for the sample prepared over 8 days, and the area of the exothermic peak for the free water crystallization is increased apparently. The change for DSC thermogram indicates that the stabilization of 30%W/O emulsion is destroyed absolutely. 

Key words:

Water-in-oil emulsuion,    , Free water,    ,  Interfacial water,    , DSC technology,    ,  Stabilizationmso-ascii-theme-font: minor-latin, mso-fareast-font-family: 宋体, mso-fareast-theme-font: minor-fareast, mso-hansi-theme-font: minor-latin, mso-ascii-font-family: Calibri, mso-hansi-font-family: Calibri">

摘要： 根据自由水和界面水冷凝时结晶的温度和热焓值不同, 采用DSC 技术分析表征了油水乳化液中不同状态的水, 还比较了油水乳化液的相对稳定性。结果表明, 当含水的质量分数超过15 %时, 样品不仅在-40 ℃出现了对应于界面水冷凝的放热峰, 而且在-18 ℃新出现自由水冷凝的放热峰, 并随水配比增加, 出峰温度略有上升。随着放置时间的增加, 30%W/ O 油水乳化液样品稳定性下降, 界面水相对含量减少, 当放置时间超过8 d 后, 在样品 DSC 谱图上不再出现界面水冷凝放热峰, 自由水冷凝对应的放热峰面积明显增大, 说明油水乳化液的稳定性被完全破坏。

关键词: 油水乳化液 , 自由水 , 界面水 , DSC 技术 , 稳定性