Preparation And Characterization Of Self-Assembly Mono-Layer Silica Microspheres And Chitosan/Silica Composite Films

In recent years, according with the development and wild application of the membrane technology, the study of the film gets more and more attentions, becomes the key point in new materials research field. As the first to be researched, silicon-based membrane has become the first choice in permeable membranes, battery films and optical films, because of its high strength, abrasive resistance, corrosion resistance, dielectric and optical properties. There are many kinds of methods to prepare the silicon-based film. Different preparation methods display different films’properties. In the second chapter of this study, we synthesized some size controllable silicon microspheres using Stober method by varying synthesis time and temperature, prepared nanometer single-layer assembly films assembled by silica microspheres, used the vertical self-assembly methods. Its structures characterized by the atomic force microscope (AFM) and electronic scanning electron microscopy (SEM).The result shows neat structures, a uniform particle size distribution and several clear images.Though there are many advantages of the pure silicon membrane, still exist some shortcomings, such as poor toughness, easy to crack defects etc., so the organic/inorganic hybrid composite membrane causes much people’s attention. Chitosan is an natural existence positive charged polymer. Because of its activity amino groups in structure, chitosan is easier to combine with TEOS to form a stable mesh structure. Because of the hydrolysis of chitosan and the dissolution of TEOS, the polymers integrate closely to form a gel. Due to chitosan’s good flexibility, the hybrid composite film improved the fault of pure silicon membrane on crack effectively. Chitosan/silica composite film has a great application future not only in catalytic medicine carrier areas, but also in artificial bone and coating of body tissue.The third chapter of this study prepared chitosan/silica hybrid composite films with chitosan and TEOS as raw materials, used sol-gel technology combined with spin coating technique. We studied the surface morphology and the hydrophilic trend of the hybrid composite films on different content of the chitosan. The results showed While the chitosan content is40%, we obtained a uniform distribution of silica spheres composite film. With the increase of chitosan content, membrane hydrophilic abates.