摘要
在磷酸系晶型控制剂的作用下 ,通过氢氧化钙悬浊液的非均相沉淀法合成了文石型晶须 ,研究了在此方法中晶型控制剂、温度以及初始 p H值等工艺因素对文石生长的影响规律。利用粉末 X射线衍射分析了所合成样品中文石的含量 ,同时用扫描电镜 (SEM)观察了合成晶须的形貌状态。经过实验发现 ,当在氢氧化钙悬浊液中添加磷酸系晶型控制剂后 ,体系具有类似的碳酸化过程 ,但是当采用磷酸或酸性的磷酸盐作为控制剂时 ,作用要优于碱性磷酸盐 ,所获得的样品中文石的含量明显较高。适合于文石生长的温度范围为 2 98K～ 348K,初始酸度值范围为 8.6～ 12 .4。通过研究镁离子与磷酸根离子对文石生长的协同作用后发现 ,镁离子对文石晶体的生长作用明显优于磷酸根 ,当它们同时存在于溶液中时 ,镁离子的作用可以掩盖磷酸根离子的作用。
Aragonite whisker was synthesized by heterogeneous precipitation from Ca(OH) 2 suspension. The influences of accelerating agents, temperature and initial pH value on the growth of aragonite were studied. X ray diffraction analysis was used to determine the content of aragonite of the final product. Shape and pattern of whiskers was observed by scanning electronic microscope (SEM). It has been found that the carbonation of Ca(OH) 2 suspension is similar upon using phosphoric acid or soluble phosphates as accelerating agent. However, the contents of aragonite of the final products are much more upon using phosphoric acid or acidic agents. The suitable temperature for the growth of aragonite is from 298K to 348K, and the adequate initial pH value range is 8 6～12 4. By investigating the synergistic influence of Mg 2+ and phosphate radical ion, it has been found that Mg 2+ affects the growth of aragonite whisker much stronger than that of phosphate radical ion.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2000年第6期398-402,共5页
Rare Metal Materials and Engineering
基金
西安交通大学博士点论文基金!资助项目 (1997- 16 )
