Fabrication And Application Of Silica Colloidal Crystal Film With Interference Effect

Colloidal crystal film has attracted wide attention due to its special structural and optical properties.The combination of colloidal crystal film and Reflectometric Interference Spectroscopy(RIf S)for sensor application is an emerging research direction.The preparation method of silica colloidal crystal film and its derivative materials was improved.The parameters affecting the film thickness and the optimal refractive index of the interference enhancement layer were theoretically analyzed.The optical interference sensing application of silica colloidal crystal films was preliminarily explored.The main work of this paper is as follows.1.Using the different humidity environment created by saturated salt solution to prepare silica colloidal crystal film,it was found that the film thickness decreases with the increase of humidity.Based on the microscopic formation process of colloidal crystal film,the parameters affecting the film thickness were studied.It was found that the humidity mainly affects the film thickness by changing the evaporation rate of wetting film solvent,and the experimental verification was carried out.Large area,uniform and controllable thickness silica colloidal crystal films were obtained by humidity control method.2.By using the interference effect of silica colloidal crystal film,the variation of optical thickness of the film with the concentration of solution was studied,the concentration of different solutions was detected accurately in real time,and the liquid with different refractive index was distinguished.A model for evaluating the cleaning ability of surfactants was built,and the change of optical thickness of the film during the cleaning process was studied by using interference effect.3.Polystyrene films with inverse opal structure were prepared by solvent evaporation and monomer polymerization,and the preparation conditions were optimized to obtain ordered porous films with stronger interference signal response.Silica colloidal crystal films with titanium dioxide interference enhancement layer were prepared by vertical deposition method.The enhancement of effective interference intensity of the films with interference enhancement layer was verified by derivation of the formula of the optimal refractive index of the interference enhancement layer and characterization of the interference spectrum.