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8244133 
Journal Article 
树枝状介孔氧化硅及其复合颗粒的制备和压缩弹性模量 
Chen, A; Ma, X; Wang, W; Cai, W; Chen, Y 
2020 
Chinese Ceramic Society 
48 
1 
65-72 
Chinese 
Dendritic-like mesoporous silica particles (DMS) were prepared via a developed oil-water biphase stratification approach using cetyltrimethylammonium bromide, tetraethoxysilane, triethanolamine, and n-hexane as starting materials. The ceria nanoparticles were grafted onto the DMS surfaces using cerium nitrate as a cerium source and hexamethylene tetramine as a precipitant, and core/shell structured DMS/CeO2 composites were obtained. The samples were characterized by scanning electron microscopy, transmission electron microscopy, low-angle X-ray diffraction, selected area electron diffraction, and nitrogen adsorption-desorption analysis. The elastic contact between an individual particle and a probe was evaluated by atomic force microscopy. The compressive elastic moduli of the DMS particles before and after ceria coating were calculated by fitting the force curves based on the Derjaguin-Müller-Toporov model. The results show that the DMS samples (ca. 92 nm in particle size) have central-radial three-dimensional mesopores with an average pore size of 6.9 nm. The average particle size of DMS/CeO2 is about 106 nm, and the thin layer of ceria nanoparticles (i.e., 5-8 nm) is uniformly coated onto the cores. The compressive modulus of DMS particles is (3.7±1.2)GPa, further revealing that an enlarged pore size contributs to the elastic response enhancement for mesoporous silica materials. The compressive modulus of DMS/CeO2 [i.e., (6.6±1.9)GPa] is much lower than that of bulk ceria materials, and much closed to that of DMS cores. The elastic response of DMS/CeO2 derives from the cores, and the coated ceria nanoparticles contributed to the surface hardness enhancement. © 2020, Editorial Department of Journal of the Chinese Ceramic Society. All right reserved. 
Atomic force microscopy; Composite particle; Compressive elastic modulus; Core/shell structure; Dendritic-like mesoporous silica