L-酒石酸水溶液结晶介稳区和诱导期的测定

Determination of metastable zone width and induction period of L-tartaric acid aqueous solution

在20~60℃温度范围内,采用激光法测定L-酒石酸在水中的结晶介稳区宽度和诱导期,分别研究了饱和温度、冷却速率和搅拌速率对L-酒石酸结晶介稳区宽度的影响以及过饱和度对L-酒石酸诱导期的影响。结果表明：结晶介稳区宽度随着饱和温度、搅拌速率的增大和冷却速率的降低而变窄,并推算出表观成核级数m,给出了成核速率方程,此外实验测定结晶诱导期随过饱和度S增大而变短,基于经典成核理论和诱导期数据,计算出L-酒石酸在水中20℃和25℃下的固液界面张力。

The crystallization metastable zone width and induction period of L-tartaric acid in water were measured by laser method at the temperature range of 20—60℃. The influences of saturation temperature, cooling rate and agitation rate on the metastable zone width and the effect of supersaturation on the induction period were explored, respectively. The results showed that the crystallization metastable zone width became narrow with rising saturation temperature and agitation rate, and decreasing cooling rate. The apparent nucleation series m and the nucleation rate equation were given. Furthermore, the experimentally measured crystallization induction period decreased with increasing supersaturation S. The solid-liquid interfacial tension of L-tartaric acid in water was calculated at 20℃ and 25℃ on basis of the classical nucleation theory and induction period data.