研究了不同PH值下、不同温度和过饱和度的KDP溶液的成核过程,测定了不同情况下溶液的诱导期。研究表明,当KDP溶液的过饱和比S〉1.3时,均匀成核起主导作用;当S〈1.2时,非均匀成核起主导作用。根据经典均匀成核理论,针对KDP过饱和溶液均匀成核的情况计算出了不同pH值、不同温度下的固一液界面张力等成核参数,并从上述参数的相互比较中分析得到了改变pH值后溶液稳定性变强的原因。最后通过对表面熵因子的计算,确定了KDP晶体的微观生长机制为连续生长模式。
The effect of different p H value on the nucleation of K H2 POe (KDP) superstatution solution was studied under different temperature. The induction period with different growth conditions was measured by the method of photography. The results indicated that when the supersaturation ratio of KDP soulution S〉1. 3, the homogeneous nucleation play a dominating role in the nucleation; when S〈1. 2, the primary nucleation mechanism is heterogeneous. According to the classical homogeneous nucleation theory, nucleation parameters have been calculated by using the experiment results. The reason why changing pH value can improve the stability of the KDP soloution could be found out through contrasting the nucleation parameters. At last, by the calculation of the surface entropy factor, the crystal surface growth model of KDP in these experiments is the model of continuous growth.