(1.北京科技大學(xué) 理化系， 北京 100083；
2.廣西大學(xué) 化學(xué)化工學(xué)院，南寧 530004)
摘 要: 應(yīng)用SEM分析測(cè)試技術(shù)，研究了納米CaCO3的生長(zhǎng)特征以及反應(yīng)溫度、添加劑及其加入量等因素對(duì)CaCO3晶體形態(tài)和粒徑的控制機(jī)理。結(jié)果表明：納米CaCO3晶體的生長(zhǎng)過程遵循MLS結(jié)晶生長(zhǎng)模型，隨Ca(OH)2濃度的增加，CaCO3的結(jié)晶生長(zhǎng)時(shí)間延長(zhǎng)，且由于碳化液粘度的增大而凝并長(zhǎng)大；反應(yīng)溫度的升高，改變了CaCO3的晶面生長(zhǎng)速率，使CaCO3粒徑增大，而且納米CaCO3呈現(xiàn)出高面網(wǎng)密度的晶體形態(tài)；添加劑的作用在于其電離產(chǎn)生的離子進(jìn)入CaCO3的晶格位置，或選擇性地吸附在CaCO3的晶面上，從而改變CaCO3的表面能，因此當(dāng)添加劑足以包覆CaCO3晶面的活性部位時(shí)，增加添加劑量，不能繼續(xù)抑制CaCO3的生長(zhǎng)。
關(guān)鍵字: 納米CaCO3；生長(zhǎng)特征；控制機(jī)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
