CAJ | 학술논문

以正硅酸已酯为硅源,以氨水为催化剂,无水乙醇为溶剂,采用溶胶-凝胶法并经500℃煅烧1 h后制备了SiO2微粒,运用激光粒度分析方法研究了各原料配比对SiO2粒子大小和粒径分布的影响;再以硝酸铈为铈源,碳酸铵为沉淀剂,十二烷基苯磺酸钠为分散剂,加入SiO2微粒,用化学沉淀法,通过控制反应和焙烧条件,经300℃煅烧1 h后成功合成了核-壳型单分散球状SiO2/CeO2复合微粒.并用差示扫描量热仪/热重分析仪、X射线衍射仪、红外光谱仪、扫描电子显微镜、透射电子显微镜和X射线能谱仪等手段以及zeta电位测定对SiO2/CeO2复合微粒的结构、组成和性能进行了表征.结果表明:SiO2/CeO2复合微粒呈规则球状,粒子分布非常均匀,粒径约300～350 nm;CeO2基本上为膜包覆,伴有少量的CeO2沉积,CeO2包覆层厚度约为30nm;SiO2包覆CeO2后所得复合微粒的表面电性质发生变化,其等电点对应的pH值从2.2增大至5.5.
이정규산이지위규원,이안수위최화제,무수을순위용제,채용용효-응효법병경500℃단소1 h후제비료SiO2미립,운용격광립도분석방법연구료각원료배비대SiO2입자대소화립경분포적영향;재이초산시위시원,탄산안위침정제,십이완기분광산납위분산제,가입SiO2미립,용화학침정법,통과공제반응화배소조건,경300℃단소1 h후성공합성료핵-각형단분산구상SiO2/CeO2복합미립.병용차시소묘량열의/열중분석의、X사선연사의、홍외광보의、소묘전자현미경、투사전자현미경화X사선능보의등수단이급zeta전위측정대SiO2/CeO2복합미립적결구、조성화성능진행료표정.결과표명:SiO2/CeO2복합미립정규칙구상,입자분포비상균균,립경약300～350 nm;CeO2기본상위막포복,반유소량적CeO2침적,CeO2포복층후도약위30nm;SiO2포복CeO2후소득복합미립적표면전성질발생변화,기등전점대응적pH치종2.2증대지5.5.
In absolute ethanolas solvent, SiO2 ultrafine particles were prepared by sol-gel method using tetraethylorthosilicate as silicon resource, ammonia as catalyst and calcining at 500 ℃ for 1 h. The effect of the ratio of the materials on the particle size and distribution of SiO2 particles were researched by the laser particle size analysis. SiO2/CeO2 core-shell composite ultrafine particles were successfully synthesized by the controlling reaction factors and using the chemical precipitation method with sodium dodecyl benzene sulfonate as dispersant, cerium nitrate as cerium resource, ammonium carbonate as precipitating agent and SiO2 ultrafme particles as cores, and calcinating at 300℃ for 1 h. The structures, composition and properties of the samples were analyzed by differential scanning calorimetry-thermal gravimetric analysis, X-ray diffraction, infrared spectrometry, scanning electron microscopy, transmission electron microscopy, energy dispersive analysis and zeta potential testing. The results indicate that the SiO2/CeO2 core-shell composite ultrafine particles have an excellent spherical morphology and uniform particle size. Their diameter is about 300-350 nm. A CeO2 can be primarily coated onto the surface of SiO2 ultrafine particle to form a shell, with a little CeO2 deposition on the SiO2 core. The thickness of the CeO2 shell is about 30 nm. After the coating has been deposited, the surface electric characteristics of the SiO2/CeO2 core-shell particles changes. The pH value at isoelectric point of the core-shell SiO2/CeO2 composite ultrafine particles increases from 2.2 for SiO2 paticles to 5.5, it is almost the same as that of CeO2 particles (pH=6.7).