分子筛成核和晶体生长动力学研究 Ⅵ.修正的Lechert模型和Avrami模型的应用

KINETIC STUDY OF ZEOLITE NUCLEATIONAND CRYSTAL GROWTH ⅥApplication of Modified Lechert Model and Modified Avrami Model

本文讨论了修正的Ｌｅｃｈｅｒｔ模型和Ａｖｒａｍｉ模型的结构特征，提出该类ＳＣ型模型适用于不同成核体系的晶体生长动力学研究。通过拟合晶化温度、胶磨、老化、氟离子分散剂和表面活性剂对分子筛晶化过程的影响，表明初始晶种的晶种量、晶种颗粒大小、晶种颗粒密度和晶体生长速率常数是分子筛晶化过程的主要影响因素。

A modified Avrami model was obtained by introducing the gel correction coefficient and the instantaneous nucleation mechanism in the system of spontaneous nucleationTheoretical study illustrated that the induction period and the rapid growth period could be satisfactorily described by three deductions of the present model respectivelyFor a group of crystal growth curves of ZSM5,The predicted results were in satisfactory agreement with the experimental results,which further implied the effect of the structure directing agent on the induction activation energy and crystal growth activation energy.