CAJ | 학술논문

采用液相碳化法制备不同形貌的纳米碳酸钙颗粒,并用TEM、SEM、XRD和IR等先进测试方法对产物进行表征.研究了十二烷基硫醇接枝聚甲基丙烯酸的加入对纳米碳酸钙制备过程的影响,结果表明,十二烷基硫醇接枝聚甲基丙烯酸能够促进碳酸钙的晶体成核,抑制晶体生长,从而可对产物的形态结构进行有效调控.添加量为2.24%(质量分数,下同)时,生成了粒径约为20～50nm的立方状蚋米碳酸钙;添加量为3.36%及以上时,生成了不同粒径的棒状纳米碳酸钙.分析了立方状和棒状纳米碳酸钙的形成机理,发现这可能与PMAA-DDT的分子结构与形状有关.同时研究了反应温度对纳米碳酸钙形态的影响,发现在较高温度下碳酸钙粒径增大,团聚严重,升高反应温度不利于控制纳米碳酸钙形貌,95℃时出现文石相碳酸钙.
채용액상탄화법제비불동형모적납미탄산개과립,병용TEM、SEM、XRD화IR등선진측시방법대산물진행표정.연구료십이완기류순접지취갑기병희산적가입대납미탄산개제비과정적영향,결과표명,십이완기류순접지취갑기병희산능구촉진탄산개적정체성핵,억제정체생장,종이가대산물적형태결구진행유효조공.첨가량위2.24%(질량분수,하동)시,생성료립경약위20～50nm적립방상예미탄산개;첨가량위3.36%급이상시,생성료불동립경적봉상납미탄산개.분석료립방상화봉상납미탄산개적형성궤리,발현저가능여PMAA-DDT적분자결구여형상유관.동시연구료반응온도대납미탄산개형태적영향,발현재교고온도하탄산개립경증대,단취엄중,승고반응온도불리우공제납미탄산개형모,95℃시출현문석상탄산개.
Calcium carbonate nanoparticles with different morphology are obtained in the presence of dodecylthioether end functionalized poly(methacrylic acid) (PMAA-DDT) via a carbonation mute.The effects of PMAADDT on carbonation process of calcium carbonate are analyzed by transmission electron microscopy(TEM),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD).The results demonstrate that the nucleation rate increase and the growth rate decrease when PMAA-DDT is added to the reaction slurry,so the morphology of calcium carbonate can be controlled.Cubic CaCO_3 particles with an average size of 20～50nm are formed at an additive concentration of 2.24wt%.While further increase in additive concentration to 3.36wt% or more rod-shaped CaCO_3 nanoparticles with different particle size can be obtained.The nucleation-growth mechanism for cubic and rod-shaped CaCO_3 nanoparticles is discussed.This may be associated with the structure and shape of PMAA-DDT.The influence of reaction temperature on morphology of CaCO_3 is also studied.Results show that morphology is not easy to control and agglomerate calcium carbonate is obtained at higher temperature.Aragonite is obtained at 95℃.