硼砂水溶液的成核诱导期

The Study on the Induction Period of Nucleation for the Aqueous Na_2B_4O_7 Solution

本文测量了不同过冷度下硼砂水溶液的成核诱导期。结果表明:测量诱导期和测量亚稳区宽度所得到的表观成核级数m是一致的。在低过饱和区,非均匀成核是主要的,实验结果偏离了均匀成核的理论表征;在高过饱和区均匀成核起着控制作用,实验和理论分析的结果吻合较好。

The induction periods of nucleation for the aqueous Na_2B_4O_7, solution were measured. It can be concluded that the value of nucleation kinetics exponent m provided by the measurements of metastable zone widths is in agreement with that obtained by measuring the induction periods of nucleation. At the low supersaturation region, experimental results deviate from the theoretical characterization of homogeneous nucleation. The results seem to indicate that at low supersaturation region (S<1.28), the heterogeneous nucleation mechanism is dominant. In the high supersaturation region (S<1.28), the homogeneous nucleation becomes rate controlling.