溶剂超声波协同法用于有机物系结晶快速成核

<正> 引言 有机物系结晶大多属于溶液群体结晶范畴,是工业结晶的重要组成部分.晶核是过饱和溶液中新生成的微小晶体粒子,是晶体生长过程必不可少的核心. A.VanHook在论述晶核的生成时指出,声波辐照由于具有强烈的定向效应,有补充和加强形成临界晶核所需的波动作用,故能加速起晶过程.高大维提出了蔗糖溶液的溶剂超声波协同成核法,该法已被利用来进行味精、含水α-葡萄糖、木糖醇等的成核研究并获得成功,所需的成核溶剂、超声波强度及刺激时间因不同物质而异.与传统的晶种制备方法(如粉碎机破碎法、球磨法、晶浆中留一部分晶体作为晶种等)相比,该法具有简单、快速、晶核数目容易控制的优点.同时还具有晶核形状好、投种量小并减少结晶生长过程中用于整晶的能耗、成品质量高等优点.溶剂超声波协同成核法的原理是溶析效应与超声波的机械(分散)效应、空化效应的结合.从溶液成核速率公式可看出表面张力σ、粘度η和过饱和度S对成核速率J的关系

STUDY ON APPLICATION OF ULTRASONIC WAVE AND ORGANIC SOLVENT IN ORGANIC SYSTEM NUCLEATION

This article summarizes the application of ultrasonic wave in nucleation of organic systemssuch as sucrose, monosodium glutamate, glutamic acid, monohydrate α-glucose, etc. and analyzesits principle . The necessary nucleation conditions for isomers of allomorphic organic system under the effect of ultrasonic wave were obtained by studying glucose. When ultrasonic wave is used to promote nucleation of organic system supersaturate solution, a nucleation solvent is usually needed. The nucleation solvent for one isomer of allomorphic organic system should be favourable to separating out the isomer. The nucleation of amphoteric substance such as antibiotic and amino acid can be achieved by only applying ultrasonic wave at its isoelectric point or by using ultrasonic wave and nucleation solvent when the system viscosity is high.