Pechini溶胶-凝胶法制备超细二氧化硅

以乙醇和去离子水为溶剂，以正硅酸乙酯为原料，柠檬酸为络合剂，采用Pechini溶胶-凝胶法制备了超细二氧化硅粉体，采用热分析（TG-DTG、DSC）、X射线衍射（XRD）分析、傅里叶红外光谱（FT-IR）分析、场发射扫描电镜（FESEM）分析等对二氧化硅粉体制备过程中的物理化学变化进行了研究。结果表明：1 000 ℃以下煅烧所得二氧化硅粉体均为非晶相，pH影响了煅烧过程中有机物的降解燃烧；煅烧温度为500 ℃时，所得二氧化硅纳米粉体的粒径约为10 nm；煅烧温度升高至600 ℃时，粉体团聚严重，晶粒尺寸增大至20 nm。

Synthesis of ultrafine silica powders by Pechini sol - gel method

Using ethanol and deionized water as solvent,tetraethyl orthosilicate as raw material,and citric acid as complexing agent,ultrafine silica(SiO₂) powders were prepared by Pechini sol-gel method.The means of TG-DTG-DSC,XRD,FT-IR,and FESEM etc.were used to analyze the physical and chemical changes during the preparation process.Results showed that the prepared SiO₂ powders were amorphous phase when calcined below 1 000 ℃;the pH had a great influence on degradation combustion of organics;the SiO₂ powders with an average particle size of about 10 nm were synthesized when calcined at 500 ℃;while calcined at 600 ℃,the SiO₂ powders seriously conglomerated and the average size increased to 20 nm.