合成了表面包覆 Si O2 的超细 Ca CO3 。通过 XPS,XRD对包覆表面层结构的分析 ,证实了 Si O2 以无定形包覆于 Ca CO3 表面 ,并在其表面形成了 Si- O- Ca键。对 Si O2 包覆超细 Ca CO3 的机理分析结果可知 :Na2 Si O3 的加入量是影响包覆效率的重要因素 ,由于硅酸易自聚 ,控制 Si O2 与 Ca CO3 的重量比约为4 %～ 5 %时为包覆的最佳点 ;Ca CO3 晶粒度大小影响分散性能 ,进而影响包覆效率 ,分散性能好的包覆效率较高。
： The superfine CaCO3 powder coated with SiO2 was synthesized. Through XRD technique, the cell parameters and crystallite size of reference and coated CaCO3 were calculated. SiO2 present in the state of amorphous and prevent the agglomeration and growth of CaCO3 micro-crystal. By comparing the result of XPS analysis of reference compound to coated sample, CaCO3 has been coated successfully with SiO2. The thickness of the coating is about 2.4～ 3.4nm. From the difference(0.8eV increase) of the binding energy of Ca2p, we presume that the bind Si-O-Ca has formed in the surface of CaCO3.
