稻壳灰制备掺杂TiO_2硅气凝胶研究

Study on the SiO_2 Aerogels Doped with TiO_2 Powder Prepared by Rice Hull Ash

以稻壳为硅源制备SiO2气凝胶,在溶胶凝胶过程中加入TiO2纳米粉末,可制得掺杂TiO2硅气凝胶。通过SEM、BET吸附-脱附测试等手段,与同种方法制得的纯SiO2气凝胶在结构和物性特征方面等进行了比较。结果显示,掺杂TiO2气凝胶的平均颗粒直径为50nm左右,而纯SiO2气凝胶的粒径约为20nm,且孔洞直径明显减小、孔径分布更为均匀;此外,TiO2纳米粉末的加入可以使气凝胶的弹性模量提高约23%,并且通过TiO2对气凝胶溶胶-凝胶过程的影响研究了其影响机理。

SiO2 aerogel doped with TiO2 powder was produced from rice hull ash by sol-gel process. The structure and properties of the doped silica aerogels and the pure silica aerogels prepared with the same method were studied by SEM and BET. It is showed that the doping of TiO2 nanopowder could increase the average particle size of samples from around 20 nm to roughly 50 nm. The pore diameter of the pure silica aerogels is much smaller and more uniformly distributed. The elastic module of samples is enhanced by 23 % with adding TiO2 nanopowders. Furthermore, the mechanism of the sol-gel process was studied.