复分解法原位合成疏水球状球霰石纳米碳酸钙

以油酸为表面改性剂，利用复分解法原位合成了疏水性球形球霰石相纳米碳酸钙颗粒，并用扫描电镜、X射线衍射、红外光谱、接触角测试等先进测定方法对产物进行表征。研究了氯化钙浓度、乙醇含量对纳米碳酸钙的影响，结果表明，增大氯化钙浓度和乙醇含量，产物粒径更小，分散性更好，但对其晶型和产物形貌影响不大，均为球形球霰石相。同时分析得出纳米碳酸钙粒子的表面性质由亲水性转变为疏水性，并探究了其表面改性的原因。

Synthesis in situ of nano-sized spherical vaterite CaCO3 with hydrophobic properties by double decomposition method

Spherical vaterite CaCO3 nanoparticles with hydrophobic properties were synthesized in situ in the presence of oleic acid as surface modifier via double decomposition method. The products were characterized by scanning electron microscopy（SEM），X-ray diffraction（XRD），Fourier transform infrared spectroscopy（FT-IR），and contact angle analysis.The effects of calcium chloride concentration and ethanol content on calcium carbonate nanoparticles were analyzed.Results demonstrated that the raising of the calcium chloride concentration and ethanol content was advantaged to prepare CaCO3 powder with smaller size and better disperse performance，but had little effect on the crystal form and morphology.Furthermore，it was analyzed that the surface properties of the vaterite CaCO3 nanoparticles changed from hydrophilic to hydrophobic.The reason of surface modification was also discussed.