K_2Ti_6O_(13)晶须掺杂对SiO_2气凝胶结构和红外透过性能的影响

Effect of K_2Ti_6O_(13) Whisker-Doping on the Microstructure and InfraredTransmittance of SiO_2 Aerogels

以正硅酸乙酯、去离子水为原料,六钛酸钾(K2Ti6O13)晶须为红外遮光剂,采用溶胶–凝胶结合非超临界干燥的方法制备了K2Ti6O13–SiO2气凝胶纳米孔复合隔热材料。采用扫描电镜,透射电镜,Fourier转换红外光谱,差热–热重分析和X射线衍射分析了K2Ti6O13–SiO2复合材料的微观结构、红外光谱特性、热重–差热和物相变化。采用N2吸附–脱附方法分析了K2Ti6O13–SiO2复合材料的孔结构。结果表明:制备的K2Ti6O13–SiO2复合材料具有三维纳米孔特征,平均孔径约为30～40 nm,K2Ti6O13–SiO2复合材料红外透过率随K2Ti6O13晶须含量的增加而减少,并且随热处理温度的升高,在3～5μm短波段区域内,红外透过率逐渐升高,而在5～8μm较高波段内,其红外透过率呈下降趋势。

Nanoporous silica-based aerogels with additive of K2Ti6O13 whisker（K2Ti6O13–SiO2 aerogels） were successfully synthe-sized by an ambient pressure drying method.The microstructure and physicochemical properties of the K2Ti6O13–SiO2 aerogels were characterized by scanning electron microscopy,transmission electron microscopy,Fourier transform infrared spectra,thermogravim-etry-differential thermal analysis and X-ray diffraction.The pore structure of the K2Ti6O13–SiO2 aerogels is 3-dimensional network with an average pore size of about 30–40 nm.The infrared transmittance of the air-dried aerogels reduces as the amount of K2Ti6O13 whisker increases,and the infrared transmittance of the heat-treated K2Ti6O13–SiO2 aerogels slightly increases at a wavelength range of 3–5 μm,and decreases at a range of 5–8 μm with the increase of heat-treatment temperature.