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采用非均匀形核法制备了Cu包覆纳米SiO2复合颗粒,利用X射线衍射仪、扫描电镜、能谱仪及透射电镜等分析手段对复合颗粒进行了表征,并探讨了包覆结构的形成机制。结果表明:复合颗粒分散均匀,无团聚,单颗粒内包含多个分布均匀的纳米SiO2颗粒,且均被Cu包覆层隔离,纳米SiO2颗粒的分散性得到了显著改善;新制备的复合颗粒不存在氧化,在存放或者制样过程中会部分氧化为Cu2O;纳米SiO2颗粒表面Cu包覆层的形成机制主要是非均匀形核作用,包覆的结构取决于 Cu晶粒在纳米SiO2颗粒表面的沉积以及对复合颗粒的团聚控制。
The Cu-coated nano-SiO2 composite particles were prepared by non-uniform nucleation method. The composite particles were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and transmission electron microscopy. The formation mechanism of the coating structure was also discussed . The results show that the composite particles are uniformly dispersed and have no agglomeration. The single particles contain a plurality of uniformly distributed nano-SiO2 particles, both of which are separated by the Cu coating layer. The dispersibility of the nano-SiO2 particles has been significantly improved. The newly prepared composite particles Which is oxidized and partially oxidized to Cu2O during storage or sample preparation. The formation mechanism of Cu coating on the surface of nano-SiO2 particles is mainly non-uniform nucleation. The structure of the coating depends on the deposition of Cu grains on the surface of nano-SiO2 particles As well as the agglomeration control of the composite particles.