Preparation Of Monolayer Ordered Porous Array Films And Its Optical/Electrical Properties

The methods of prepare inorganic optical film includes magnetron sputtering,chemical deposition,electrodeposition,etc.,These routes,however,are far from practical application due to difficulty in operation,high preparation cost,or environmental damage,etc..In this study,the alternative route to prepare macroporous ordered array films was explored by using polystyrene microspheres or silica microspheres as templates based on the simple L-B films technology,and solid-liquid-gas three-phase interface self-assembly method were used.Thereafter,the relationship between structure and properties was studied.This thesis is divided into three parts:(1)A series of macroporous hollow silica sphere monolayer array films is successfully obtained by using hollow silica microspheres as block unit.After the PS spheres template is removed by high-temperature calcination,a series of hollow silica microspheres monolayer array films with adjustable size are obtained.And its visible light transmission characteristics were further studied.The results show that as the diameter of the microspheres increases,the visible light transmittance of the film decreases.In addition,introduce hollow structure can significantly increase the visible light transmittance;the transmittance of hollow silica microsphere array film(with thickness of 460 nm)reached at 90%at the wavelength 550 nm,which is significantly higher than the that of solid silica microsphere array film(thickness 480 nm,75%).(2)Mesoporous silica@solid silica microsphere composite array film were prepared by introducing mesoporous silica into solid silica microsphere monolayer array film by dipping-coating technique,and its optical and mechanical properties(abrasion resistance)are explored.Studies have shown that the dipping time and lifting speed have an important influence on the thickness and morphology of the composite film.The visible light transmittance is found to increases from 67%to 73%after mesoporous silica are composited with the solid silica microsphere film(540 nm)at the wavelength of 500 nm,which demonstrates visible transmittance of the film can be improved by introducing a mesoporous silica layer,and the abrasion resistance properties of the solid silica microsphere monolayer array film is improved.(3)Using PS microspheres as a template and nickel nitrate as the precursor,a nickel oxide(hydroxide)inverse opals monolayer film with hexagonal close-packed honeycomb structure prepared by dynamic hard-template technology.Studies show that the concentration of nickel nitrate plays a decisive role on the structure of nickel oxide(hydroxide)inverse opal monolayer film:a higher concentration of nickel nitrate solution is beneficial to obtain a highly ordered densely packed inverse opals film,the optimum concentration is 0.3 g/ml under this experimental conditions.The electrochromic properties of the nickel oxide inverse opals monolayer film are related to the calcination temperature of the nickel nitrate@PS composite film:the calcination temperature increases,and the visible electrochromic modulation range(at the wavelength of 700 nm)decreases.The inverse opal film has superior visible light modulation capability compared to the conventional nickel oxide film(25%):the coloration range at the wavelength of 700 nm is 33.1%.Therefore,the film will have broad application prospects in electrochromic devices such as smart windows.