粒度和温度对纳米Ca(OH)_(2)溶解行为的影响  

Effects of particle size and temperature on dissolution behavior of nano Ca(OH)_(2)

作　　者：肖杰 何浩 王祥柱[3] 陈群[3] 李东阳[1] XIAO Jie;HE Hao;WANG Xiangzhu;CHEN Qun;LI Dongyang(State Key Laboratory of Powder Metallurgy Research Institute,Central South University,Changsha 410083,China;School of Electronic Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China;Xiangya Stomatological Hospital of Central South University,Changsha 410008,China)

机构地区：[1]中南大学粉末冶金研究院国家重点实验室,湖南长沙410083 [2]广西科技大学电子工程学院,广西柳州545006 [3]中南大学湘雅口腔医院,湖南长沙410008

出　　处：《广西科技大学学报》2023年第1期112-120,共9页Journal of Guangxi University of Science and Technology

基　　金：国家自然科学基金项目(52164042);长沙市自然科学基金项目(kq2014215)资助。

摘　　要：以微米级到纳米级的Ca(OH)_(2)粉末作为原料,采用pH玻璃电极的测试方法分析粉末粒度和溶解温度对Ca(OH)_(2)溶解过程的影响。研究表明:溶解过程在表面反应控制条件下,拟合得到的表观溶解速率常数随着粒度的减小而增大,当溶解温度由25℃增加到55℃、平均粒度由3.81μm降低到56.47 nm时,Ca(OH)_(2)的表观溶解速率常数从6.17×10^(-4)mol/(L·s)增加到了2.01×10^(-3)mol/(L·s),Ca(OH)_(2)的表观溶解反应级数为1.78;当温度分别为25℃、35℃、45℃、55℃时,粒度与表观溶解速率常数呈函数关系。利用Arrhenius方程回归获得平均粒度为3.81μm、0.82μm、78.90 nm、56.47 nm的Ca(OH)_(2)粉末在25~55℃条件下的表观溶解活化能分别为31.99 kJ/mol、31.73 kJ/mol、27.55 kJ/mol、17.80 kJ/mol。纳米Ca(OH)_(2)溶解能够在更短的时间达到较高的pH值,有提高根管消毒效率的可能。With Ca(OH)_(2)powders of micron to nanometer scale as raw materials,the effects of particle size and dissolution temperature on the dissolution process of Ca(OH)_(2)were analyzed by measuring the pH glass electrode.The results show that under the condition that the dissolution process was controlled by surface reaction,the apparent dissolution rate constant obtained by fitting increased with the decrease of particle size.When the temperature increased from 25℃to 55℃and the particle size decreased from 3.81μm to 56.47 nm,the apparent dissolution rate constant of Ca(OH)_(2)increased from6.17×10^(-4)mol/(L·s)to 2.01×10^(-3)mol/(L·s).The apparent order of dissolution of Ca(OH)_(2)was 1.78.The function relationship between particle size and apparent dissolution rate constant at 25℃,35℃,45℃and 55℃was obtained from the experimental results.The apparent solubility activation energies of3.81μm,0.82μm,78.90 nm and 56.47 nm-Ca(OH)_(2)powders at 25~55℃were 31.99 k J/mol,31.73 kJ/mol27.55 kJ/mol and 17.80 kJ/mol respectively,by using Arrhenius equation regression.Dissolved calcium hydroxide nanoparticles are able to reach a higher p H in a shorter time and have the potential to improve the efficiency of root canal disinfection.

关 键 词：纳米粒子 溶解 动力学 氢氧化钙(Ca(OH)_(2)) 速率常数 溶解活化能 

分 类 号：O642[理学—物理化学]