疏水改性对SiO_2气凝胶薄膜性能与结构的影响  

Effect of Hydrophobic Modifying on the Properties and Structure of Silica Aerogel Films

作　　者：曹旗[1] 吴清仁[1,2] 吴启坚[1] 叶春瑜[1] 赵韵[1] 黄文峰[1] 陈嘉[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广州510640 [2]华南理工大学特种功能材料教育部重点实验室,广州510640

出　　处：《材料导报》2011年第10期92-95,109,共5页Materials Reports

基　　金：国家自然科学基金(59576027);广东省自然科学基金(011552)

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。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 particies 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 po- rosity is 78. 80% and the density of the films is 0. 464g/cma. This is a typical nano-prous network structure.

关 键 词：SiO2气凝胶薄膜 六甲基二硅胺烷 疏水改性 物理性能 微观结构 

分 类 号：TQ174[化学工程—陶瓷工业]