六钛酸钾晶须掺杂改性气凝胶的结构和性能

摘要

以六钛酸钾晶须(PTW)为遮光剂,掺入Si02气凝胶中降低气凝胶的热导率.研究偶联剂的种类和添加量、PTW掺入量对气凝胶热导率、密度和比表面积等性能的影响.采用X线衍射仪(XRD)、傅立叶红外光谱仪(FT- IR)、扫描电子显微镜(SEM)对气凝胶进行表征.结果表明:0.5 mL KH550对10 g PTW进行表面改性后,将PTW按照质量分数28.57％掺入SiO2气凝胶中可使其热导率降至0.023 55 W/(m·K).PTW在气凝胶中保持原有的晶体结构,SiO2仍保持无定形网络结构.%Titanium potassium whisker ( PTW) was used as opacifier to reduce the thermal conductivities of SiO2 aerogels. The effects on thermal conductivity, density, specific surface area with category and dosage of coupling agent, and dosage of PTW were investigated. The aerogels were characterized by X-ray diffraction (XRD) , Fourier transform infrared spectroscopy ( FT-IR) , and scanning electron microscope (SEM). The results showed that 10 g PTW was modified by 0. 5 mL KH550,and then 28. 57% PTW in SiO2 aerogels could reduce the thermal conductivity to be 0. 023 55 W/(m'K). PTW remained the crystal structure in SiO2 aerogels,and SiO2 kept its amorphous network structure.