Na_5P_3O_(10)-Ca(OH)_2-CO_2-H_2O体系纳米CaCO_3的成核与生长

通过化学分析、SEM显微分析技术结合RosinRamiler概率统计理论从介观层次研究Na5P3O10CaOH2CO2H2O体系纳米CaCO3的合成反应及其成核和生长过程。结果表明Na5P3O10对CaOH2的碳化反应具有抑制作用。随着Na5P3O10的增加体系中CaCO3的成核速率B0逐渐增大。在Na5P3O10=0ppm时CaCO3结晶的生长由长程扩散和凝聚生长控制Na5P3O10=380.4760.9ppm时前期受短程扩散和界面反应控制、后期受长程扩散控制。Na5P3O10的存在抑制了纳米CaCO3的晶体生长。

The Nucleation and Growth of Nanometer CaCO_3in the Na_5P_3O_(10)-Ca(OH)_2-CO_2-H_2O System

The nanometer CaCO3synthesis reaction,nucleation and growth in Na 5P3O10-Ca (OH)2-CO2-H2O system were investigated using chemical analysis,SEM and Rosin-Ramul er probability statis-tics theory.The nucleation rate B0 was calculated using mass and popula tion balance.The results showed that the Ca (OH)2carbonation reaction can be inhibited by Na 5P3O10.In the crystallization process,the CaCO3 nucleates rapidly in the initial sta ge,and then the nucleation rate B0decreases gradually.In the system whichCaCO3]=0,380.4ppm,the tiny CaCO3nuclei dissolve and the nucleation rate is negative at the fi nally stage.The CaCO3nucleation rate B0increases with the increase ofNa5P3O10].The CaCO3crystal growth experienced the long distance diffusion and ag-glomeration growth stages whenNa5P3O10]=0ppm.WhileNa5P3O10]=380.4,760.9ppm,the nanometer CaCO3nucleus growth is controlled by the s hort distance diffusion and interfa ce reaction at first,and then it is controlled by th e long distance diffusion while CaCO3nucleus growth according to parabola law(n=0.4878,4.884).Na 5P3O10is able to inhabit the growth of nanom eter CaCO3crys-tal.