(1.北京科技大学 理化系， 北京 100083；
2.广西大学 化学化工学院，南宁 530004)
摘 要: 应用SEM分析测试技术，研究了纳米CaCO3的生长特征以及反应温度、添加剂及其加入量等因素对CaCO3晶体形态和粒径的控制机理。结果表明：纳米CaCO3晶体的生长过程遵循MLS结晶生长模型，随Ca(OH)2浓度的增加，CaCO3的结晶生长时间延长，且由于碳化液粘度的增大而凝并长大；反应温度的升高，改变了CaCO3的晶面生长速率，使CaCO3粒径增大，而且纳米CaCO3呈现出高面网密度的晶体形态；添加剂的作用在于其电离产生的离子进入CaCO3的晶格位置，或选择性地吸附在CaCO3的晶面上，从而改变CaCO3的表面能，因此当添加剂足以包覆CaCO3晶面的活性部位时，增加添加剂量，不能继续抑制CaCO3的生长。
关键字: 纳米CaCO3；生长特征；控制机理
controlling mechanism of
nanometer CaCO3
（1.Department of Physico-Chemistry,
University of Science and Technology Beijing，
Beijing 100083，China；
2.College of Chemistry and Chemical Engineering，
Guangxi University，Nanning 530004, China）
Abstract:The growth characteristics of nanometer CaCO3， the controlling mechanism of temperature，Ca(OH)2 concentration，additive species and adding amount acting on nanometer CaCO3 morphology and particle size were investigated by means of SEM. The results show that the growth of nanometer CaCO3 particles obeys MLS crystal growth model. With the increasing of Ca(OH)2 concentration，the CaCO3 crystal growth periods were found to be extended，and the aggregation growth of the nanometer CaCO3 particles due to the viscosity increase of the carbonation susp en sion was observed. The rise in reaction temperature may increase the CaCO3 crystal growth rate causing larger grain radii，also the CaCO3 crystal can reveal a morphology with higher lattice networking density. The ions produced due to the electroionization of the additive species can occupy the CaCO3 lattice-sites，or be absorbed on CaCO3 crystal faces，therefore changing the CaCO3 crystal surface energy. Hence，when the additive amount is large enough to cover active sites on crystal faces， the increasing of additive concentration can not further inhabit crystal growth.
Key words: nanometer CaCO3；growth characteristics；controlling mechanism
