硫酸钾水溶液亚稳区性质的研究(Ⅲ)——成核诱导期

Studies on the Characteristics of Metastable Zone of the Aqueous K2SO4 Solution ( Ⅲ )——The Induction Period of Nucleation

按照过饱和溶液产生的方式,研究其亚稳态行为可分为两种类型:一是研究亚稳区宽度随过饱和度（或过冷度）的变化;二是测量恒定过饱和度下的诱导期。前者在前文中已进行了分析讨论。本文旨在测定K2SO4水溶液诱导期的基础上,进行理论分析和成核特征值的计算,并将两种方法加以比较。

The induction periods of nucleation for the aqueous K2SO4 solution were measured. It can be concluded that the value of nucieation kinetics exponent m provided by the measurements of metastable zone widths is in better agreement with that obtained by measuring the induction periods of nucleation. At the low supersaturation region, experimental results deviate from the theoretical characteristics of homogeneous nucleation. The results seem to indicate that at low supersaturation region(S<1. 08), the heterogeneous nucteation mechanism is dominant. In the high supersaturation region(S>1.1),the homogeneous nucleation becomes the rate-controlling step.