Meng Zong, Yang Lijun, Geng Wenxin, Yao Yubo, Wang Xingguo, Liu Yuanfa
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
Patent Examination Cooperation Center of the Patent Office, No. 3 Building, No. 11 Gaoliangqiaoxie Street, Haidian District, Beijing 100081, China.
ScientificWorldJournal. 2014 Feb 19;2014:149753. doi: 10.1155/2014/149753. eCollection 2014.
The isothermal and nonisothermal crystallization kinetics of monoglyceride (MAG) organogels were studied by pulsed nuclear magnetic resonance (pNMR) and differential scanning calorimetry (DSC), respectively. The Avrami equation was used to describe the isothermal crystallization kinetics and experimental data fitted the equation fairly well. Results showed that the crystal growth of MAG organogels was a rod-like growth of instantaneous nuclei at higher degrees of supercooling and a plate-like form with high nucleation rate at lower degrees of supercooling. The exothermic peak in nonisothermal DSC curves for the MAG organogels became wider and shifted to lower temperature when the cooling rate increased, and nonisothermal crystallization was analyzed by Mo equation. Results indicated that at the same crystallization time, to get a higher degree of relative crystallinity, a higher cooling rate was necessary. The activation energy of nonisothermal crystallization was calculated as 739.59 kJ/mol according to the Kissinger method. Therefore, as the results of the isothermal and nonisothermal crystallization kinetics for the MAG organogels obtained, the crystallization rate, crystal nucleation, and growth during the crystallization process could be preliminarily monitored through temperature and cooling rate regulation, which laid the foundation for the real industrial manufacture and application of the MAG organogels.
分别采用脉冲核磁共振（pNMR）和差示扫描量热法（DSC）研究了甘油单酯（MAG）有机凝胶的等温及非等温结晶动力学。采用阿弗拉米方程描述等温结晶动力学，实验数据与该方程拟合良好。结果表明，在较高过冷度下，MAG有机凝胶的晶体生长为瞬时核的棒状生长，在较低过冷度下为具有高成核速率的板状生长。当冷却速率增加时，MAG有机凝胶的非等温DSC曲线中的放热峰变宽并向低温移动，并用莫方程分析非等温结晶。结果表明，在相同的结晶时间下，为了获得更高的相对结晶度，需要更高的冷却速率。根据基辛格方法计算出非等温结晶的活化能为739.59 kJ/mol。因此，通过对MAG有机凝胶的等温及非等温结晶动力学研究，可通过温度和冷却速率调节对结晶过程中的结晶速率、晶核形成及生长进行初步监测，为MAG有机凝胶的实际工业化生产及应用奠定了基础。
