不同pH值下磷酸二氢钾晶体的生长实验

用称重法测定了不同pH值下磷酸二氢钾(KDP)的溶解度曲线,进行了不同pH值时KDP溶液的稳定性实验,通过对雪崩点的观测得到了不同pH值下KDP溶液的过饱和度曲线,给出了相应的亚稳区宽度,并开展了不同pH值下KDP晶体的生长实验。结果表明:随着KDP生长溶液pH值的升高或降低,KDP溶解度都会明显增大,同时溶液的亚稳区宽度变大、溶液稳定性提高,并且发现略高于正常pH值的KDP饱和溶液对晶体的生长更为有利。

KDP crystal growth in differing pH value

Variation of solution pH value influences the quality of and the growth patterns of KDP crystals.The solubility curves of KDP(KH2PO4) solutions with differing pH values were obtained by the weighing method.The supersaturation curves of these solutions were observed by surveying the first visible crystal's temperature.The widths of the relevant metastable zone were obtained.The results show that KDP solubility increases with the increasing or decreasing growth solution pH value.With these changes,the metastable zone of solutions expands and the stability improves.A slightly higher pH value of KDP solution than normal was found to be more suitable for growing high-quality and large-sized crystals.