表面活性剂对丁二酸冷却结晶中聚结的抑制

借助聚焦光束反射测量仪(FBRM)和颗粒录影显微镜(PVM)对丁二酸冷却结晶过程中的聚结现象进行研究,通过加晶种实验和不加晶种实验初步推断大小颗粒的共存及颗粒间的相互结合力是形成聚结需要考虑的两个因素。在此基础上,将3种类型的表面活性剂十六烷基三甲基溴化铵(CTAB)、十二烷基苯磺酸钠(SDBS)和吐温80(Tween80)加入到丁二酸冷却结晶系统,考察了表面活性剂对结晶过程中颗粒聚结的抑制作用。晶体形貌变化表明,所选的表面活性剂均能吸附于晶体表面,且可大大降低聚结,可推测表面吸附产生的机械隔离能够降低晶体间的相互结合力,并促使结晶产品的粒度更为均匀。这一研究证明添加表面活性剂可降低结晶过程的聚结程度。

Inhibition of Surfactants on Agglomeration of Succinic Acid in Cooling Crystallization

The agglomeration phenomenon of succinic acid in cooling crystallization was analyzed by FBRM (Focused Beam Reflectance Measurement) and PVM (Particle Video Microscope). It was found in the experiments with seeding and without seeding that both the coexistence of particles with different sizes and adhesion between particles were two factors in forming agglomeration. On this basis, surfactants, such as cetyltrimethylammonium bromide (CTAB), sodium dodecyl benzene sulfonate (SDBS) and Tween80 were added into the crystallization solution, respectively, and the effects of surfactants on the agglomeration of particles during crystallization were investigated. The change of crystal morphology showed that the selected surfactants could be adsorbed on the surface of the crystals and could greatly reduce the agglomeration. It could be deduced that the mechanical isolation due to surface adsorption could reduce the mutual bonding forces between the crystals and make the particles of the crystal products more uniform.This study demonstrated that the addition of surfactants can reduce the degree of agglomeration during crystallization.