机构地区: 华南理工大学
出 处: 《陕西科技大学学报(自然科学版)》 2007年第1期26-31,共6页
摘 要: 研究了超声场作用对反应结晶过程中成核诱导期的影响.以碳酸钙为实验对象,在不同频率和超声作用时间下观察了成核诱导期的变化,结果表明,结晶诱导期随着超声作用时间的增加而缩短.机理分析认为超声场对成核过程的主要影响有两个方面:溶液表面张力的下降和扩散系数的上升.超声场作用可降低成核诱导期. The effect of ultrasound on reactive crystallization is studied by measuring the induction time. Calcium carbonate is used as the working substance precipitated by mixing CaCl2 and Na2CO3/NaHCO3 solutions. The experiments were carried with various frequencies and insonation time. It is observed that the induction time significantly decreases with increasing insonation time. The mechanismof the ultrasonic effect on nucleation is analyzed.The two effects of ultrasound are discussed. The surface tension (γ) decreased and the diffusion coefficient (DAB) increased in the ultrasound. The induction time reduced after ultrasound treating.