Pechini溶胶-凝胶法制备超细二氧化硅

摘要

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.%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:1000℃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20nm.