以非离子表面活性剂F127为模板,正硅酸乙酯为硅源,在酸性条件下合成胶体通过溶剂蒸发诱导自组装的方式制备了单层薄膜,经氨气预处理和高温煅烧除去模板剂后得到介孔氧化硅薄膜.利用同步辐射掠入射x射线衍射、氮气吸脱附和透射电子显微镜研究了薄膜的介观结构,发现薄膜内部呈现有序的笼型孔道结构,可归属于体心立方排列.通过紫外.可见光谱仪和椭偏仪研究了薄膜的光学性质,在1053nm波长处光学透射率可达99.9%以上,折射率可依F127/Si摩尔比而变.采用原子力显微镜研究了薄膜的表面性质,薄膜表面平整,平均粗糙度仅为1.2nm.使用1053nm激光测试薄膜的激光损伤阈值,所有样品阈值均大于25J.cm≈(脉宽为1ns).该薄膜制备方法有望成为一种大口径减反射膜制备新方法.
Single-layer silica films are prepared via evaporation-induced-self-assembling process using triblock copolymer surfactant F127 as template and tetraethoxysiliane as precursor under acidic condition. After ammonia pretreatment, the as-deposited films undergo a thermal decomposition process to remove the surfactant, and the mesopores are formed in film. Three techniques are used to character- ize the mesoscopic structure of film, i.e., grazing-incidence X-ray diffraction, nitrogen adsorption/desorption and transmission electron microscopy. The results indicate that the film has an ordered cage-like porous structure and can be indexed as the body-centered-cubic arrangement. The optical properties of the films are investigated Via ellipsometry and UV-VIS-NIR transmission spectrometer. The transmitance can reach up to 99.9% at 1053 nm wavelength. The refractive index varies with the molar ratio of F127/Si. Atomic force microscope is used to probe the surface morphology, and the surface roughness Ra is 1.2 nm. A 1053 nm laser is used to determine the laser damage threshold of film and all the thresholds are higher than 25 J.cm-2 (1 ns). This method has a potential application in the preparation of large-aperture antireflective films.