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以正硅酸乙酯为硅源、以氨水为催化剂、十六烷基三甲基溴化铵为结构导向模板剂,在单分散实心氧化硅(Solid-SiO2,SSiO2)内核表面包覆介孔氧化硅(Mesoporous-SiO2,MSiO2)外壳,合成了同质异构氧化硅(SSiO2/MSiO2)核/壳复合磨粒。用小角XRD、FESEM、HRTEM、FTIR、TGA和氮气吸附-脱附等手段对样品的结构进行了表征。结果表明,具有放射状介孔孔道的MSiO2均匀连续包覆在SSiO2内核(210-230nm)外表面,形成了厚度为70-80nm的外壳。壳层中的介孔孔道(孔径约2-3nm)基本垂直于内核表面,且复合磨粒样品具有较大的比表面积(558.2m2/g)。用AFM形貌分析和轮廓分析评价了所制备的复合磨粒对SiO2薄膜的抛光特性。与常规实心SiO2磨粒相比,SSiO2/MSiO2复合磨粒明显改善了抛光表面质量并提高了材料去除率。这可能归因于MSiO2壳层通过机械和/或化学方面的作用对磨粒与衬底之间真实界面接触环境的优化。
Using tetraethyl orthosilicate as silicon source and ammonia as catalyst, cetyltrimethylammonium bromide was used as structure-oriented template to coat mesopores on the surface of solid-SiO2 (SSiO2) (SSiO2 / MSiO2) core / shell composite abrasive grains were synthesized from the shell of silica (Mesoporous-SiO2, MSiO2). The structure of the sample was characterized by XRD, FESEM, HRTEM, FTIR, TGA and nitrogen adsorption-desorption. The results show that MSiO2 with radial mesopores is uniformly and continuously coated on the outer surface of the SSiO2 core (210-230nm), forming a shell with a thickness of 70-80nm. The mesoporous channels in the shell (about 2-3 nm in diameter) are generally perpendicular to the surface of the core, and the composite abrasive grain sample has a larger specific surface area (558.2 m2 / g). The polishing characteristics of the SiO2 film prepared by the composite abrasive particles were evaluated by AFM morphology analysis and contour analysis. The SSiO2 / MSiO2 composite abrasive particles significantly improve the polished surface quality and increase the material removal rate compared to conventional solid SiO2 abrasive particles. This may be attributed to the optimization of the real interfacial contact environment between the abrasive grains and the substrate by the mechanical and / or chemical effects of the MSiO2 shell.