二氧化硅气凝胶的制备及性质研究

Study on Preparation and Properties of Silica Aerogel

高度交联多孔网状二氧化硅气凝胶材料拥有高比表面积、高孔隙率、低密度等优点在航空航天、军事应用、节能建筑等方面有着广泛的应用。研究以正硅酸四甲酯为硅源,通过制备过程中水含量的控制来获得四种前驱体,在常压下采用一步合成法成功制备二氧化硅气凝胶。该方法具有工艺时间短、溶剂使用量少、能耗低等特点。采取红外光谱分析、热重分析、X射线衍射分析和接触角的测量对实验室制备的二氧化硅气凝胶进行性质表征,发现其具有良好的热稳定性和疏水性。

The highly crosslinked porous reticulated silica aerogels have the advantages of high specific surface area,high porosity and low density.Silica aerogels have been widely used in aerospace,military applications,energy saving buildings and so on.Four precursors were obtained by controlling the water content in the preparation process using tetramethoxysilane as silicon source.Silica aerogels were successfully prepared by one-step synthesis method with different precursors under atmospheric pressure.The method for aerogels preparation has the characteristics of short process time,less solvent usage and low energy consumption.The properties of sample prepared were characterized by infrared spectrum analysis,thermogravimetric analysis,X-ray diffraction analysis and contact angle measurement.It was found that the prepared silica aerogels had good thermal stability and hydrophobicity.