沉淀法制备高比表面积SiO_2的工艺研究  

Study of Preparation of Silica with High Specific Surface Area Using Precipitation Method

作　　者：游淳毅[1] 汤培平[1] 刘碧华[1] 林康英[1] 刘瑞聪[1] 

机构地区：[1]厦门大学化学化工学院,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2013年第1期75-80,共6页Journal of Xiamen University：Natural Science

基　　金：福建省科技计划项目(2010H6024)

摘　　要：以Na2SiO3·9H2O、H2SO4为原料,沉淀法路线合成高比表面积SiO2.实验考察了反应温度、H2SO4溶液浓度、Na2SiO3溶液浓度、反应终点pH值、表面活性剂添加量、后处理试剂、干燥方式等因素对SiO2比表面积的影响.采用BET低温液氮吸附比表面分析仪、热重分析仪、场发射扫描电镜、激光粒度分析仪、傅里叶变换红外光谱仪等分析仪器对SiO2样品进行表征.结果表明,在c(H2SO4)=1.5mol/L、w(Na2SiO3)=6.3%、反应温度t=60℃、pH值为5,用正丁醇置换水等实验条件下,可制得SiO2粉末比表面积为841m2/g,相较于一般沉淀SiO2300～400m2/g的比表面积有明显提高.Silica with high specific surface area was successfully prepared from sodium silicate solution and sulfuric acid using precip- itation method. The aim was to study the effects of various factors in the preparation process, which include temperature, concentra- tion of sulfuric acid,mass fraction of sodium silicate, pH of the reaction system, surfactants, post-processing reagent and the drying method. The silica samples prepared in different conditions were characterized by BET, thermogravimetric analysis （TG）, scanning e lectron microscope （SEM） ,laser particle size analyzer （LDSA） and Fourier transform infrared （FT-IR）. Optimum condition was es- tablished for carrying out the precipitation process of silica. The specific surface area of silica can reach up to 841 me/g with the opti- mum condition of c（ H2SO4 ） -- 1.5 mol/l., w（ Na2SiO2 ） = 6.3 %, t = 60 ℃ , pH 5. The specific surface area is improved remarkably compared with the regular value of 300-400 me/g using precipitation method.

关 键 词：SIO2 高比表面积 沉淀法 

分 类 号：TQ420.6[化学工程] O612.4[理学—无机化学]