利用Mydlarz和Jones模型(MJ2),对乙酸丁酯中青霉素亚砜的成核与生长动力学进行研究。通过矩量法对MJ2模型进行处理后,利用晶体产品的粒度分布计算得到青霉素亚砜的生长速率与成核速率,然后利用最小二乘法拟合回归求解出成核与生长动力学方程参数。通过实验设计考察了过饱和度、温度与搅拌速度对青霉素亚砜晶体成核和生长过程的影响。研究表明青霉素亚砜晶体生长速率随过饱和度比的增加呈现指数型增长,确定青霉素亚砜晶体生长属于晶体表面生长控制过程。由于高速搅拌会增加青霉素亚砜晶体的破碎,促进了二次成核过程,随着搅拌速度的增加,晶体生长速率出现小幅下滑,而成核速率则明显升高。青霉素亚砜成核与生长动力学研究将有助于工业生产过程优化。
The crystal growth and nucleation kinetics of penicillin sulfoxide in butyl acetate were studied with Mydlarz & Jones model, which fits the experimental values best. After the model was treated by moment transformation, the crystal growth and nucleation rates were calculated from the crystal size distribution. The parameters in crystallization kinetic functions were obtained with the least square method. The effects of supersaturation ratio, temperature and agitator speed were examined, In conclusion, the crystal growth of penicillin sulfoxide is controlled by surface growth because the growth rate increases greatly with the increase of supersaturation ratio. High agitator speed results in the breakage of penicillin sulfoxide crystals and improves the secondary nucleation. As a result, crystal growth rate decreases and nucleation rate increases with the increase of agitator speed. The study on crystal growth and nucleation kinetics will be beneficial to the industrial production of penicillin sulfoxide.