【摘要】 以正硅酸乙酯(TEOS)为前驱体,采用溶胶-凝胶法制备SiO2气凝胶薄膜,并以不同体积分数的六甲基二硅胺烷(HMDZ)对SiO2气凝胶薄膜进行了疏水改性研究,采用椭偏仪、FITR、接触角测试仪、SEM和光谱仪等对薄膜的疏水性、微观结构及透光性进行了表征,研究了HMDZ疏水改性对SiO2气凝胶薄膜性能与结构的影响。结果表明,疏水改性后,SiO2胶粒表面的大部分亲水性-OH被疏水基团-CH3所取代,其与水的接触角达159°,疏水性好;SiO2气凝胶薄膜在可见光范围内透光率接近90%,透光性高;其孔隙率为78.8%,密度为0.464g/cm3,骨架颗粒尺寸小于40nm,具有纳米多孔网络结构特性。更多还原

【Abstract】 Transparent hydrophobic silica aerogel films were successful prepared by using tetraethyoxysilane(TEOS) as silicon source and modified with various volume-concentration of hexamethyldisilazane(HMDZ) via Sol-gel process.Ellipsometry,FTIR,contact angle instrument,SEM and spectrometer were used to characterize the hydrophobic property,microstructure and transparence of silica aerogel films.The results show that hydrophilic-OH groups on the surface of silica particles have been mostly replaced by hydrophobic-CH3 groups,the contact angle between silica aerogel films and water droplet is up to 159°,which suggests that the films have excellent surface hydrophobicity.The percentage of transmission of silica aerogel films in the range of visible light reaches to 90%,which indicates that the films have good transparence.The sizes of particles in silica aerogel films are less than 40nm,the porosity is 78.80% and the density of the films is 0.464g/cm3.This is a typical nano-prous network structure.更多还原