头孢地嗪钠溶剂化物结晶过程自催化动力学

Autocatalytic kinetics of cefodizime sodium solvate in crystallization

采用在线拉曼光谱在不同结晶温度和溶液初始浓度的条件下,研究了头孢地嗪钠溶剂化物结晶过程的动力学行为,从热力学和成核机理的角度分析了温度和初始浓度对动力学的影响。根据动力学曲线的特征,将头孢地嗪钠溶剂化物的结晶过程假定为'自催化'过程。针对头孢地嗪钠溶剂化物结晶过程的特殊性,修正了Prout-Tompkins模型;并通过不同温度下的动力学数据,采用多元线性回归拟合了头孢地嗪钠溶剂化物结晶过程的自催化动力学模型参数E和k。

The analysis on the crystallization of cefodizime sodium solvate shows that the conversion-time curve presents three characteristics： S-shape, the turning-point, and the turning-point corresponding to the maximum crystallization rate. Therefore, the crystallization of cefodizime sodium solvate could be assumed as an autocatalytic process, and the Prout-Tompkins model was modified according to the solubility curve in order to apply in solution crystallization. The autocatalytic kinetics of solvate crystallization was studied at different temperatures and initial concentrations. The effect of temperature was explained from two aspects, thermodynamics and nucleation mechanism. The kinetic parameters （activation energy E and pre-exponential factor k） of the autocatalytic kinetic models were estimated by multiple linear regression method.