硅酸盐学报

开发了一种制备多孔SiO2 涂层的新方法 ,该方法综合了溶胶凝胶法、化学沉淀法和离子交换法的特点。首先采用溶胶凝胶工艺合成SiO2 溶胶 ,然后利用化学沉淀法 ,以Na2 CO3为碱性沉淀剂使SiO2 溶胶快速凝胶 ,在经过处理的基材表面形成涂层前驱体 ,再通过离子交换法除去由沉淀剂引入的金属阳离子 ,最后经过 40 0～ 5 0 0℃热处理 ,不经过复杂的凝胶化过程即制备出性能良好的非晶化多孔SiO2 涂层。SEM ,FTIR ,NMR和XRD分析表明 :制备的SiO2 涂层表面有吸附性硅烷醇基团 ,具有多孔、非晶态等特点 ,因此它外表面积可达1.64× 10 6 cm2 ·cm- 3,亲水性好且耐高温 ,在吸附和催化领域有广阔的应用前景

A novel approach for the preparation of porous silica coating was developed by experimental research, which integrated the methods of solgel, chemical precipitation, and ion exchange. Silica sols are initially synthesized by means of solgel technology. Then taking Na 2CO 3 as alkaline precipitator, the coating precursor is quickly deposited on the substrate surface through chemical precipitation. Alkali metal ions in the precursor, induced from precipitation agents, are removed by ion-exchange process. Following post treatment, amorphous silica can be ultimately obtained. The difference between this method and the methods usually used for preparing porous silica is that it is unnecessary to have the complex gelation process. SEM, XRD, NMR and FTIR absorption spectra are used to characterize the resultant features of porous structure, surface silanol groups, and amorphous phase. The results show that the external surface area of the coating obtained can reach up to 1.64×10 6cm 2·cm -3.It also possesses good hydrophilicity and heat-resistance. There is a bright prospect for the materials in the application of absorption and catalyst etc.