The Functionalization Of Silica Nanoparticles Modified And Applied Research

Closely related to the particle size and morphology of nanomaterials and their performance, this article through to the precision control of reaction parameters, on the basis of silicon dioxide was prepared by a variety of composite nanostructures, and the morphology and properties of the composite nanomaterials are studied, proved that this kind of composite materials in catalytic and optical field has a broad application prospect. The main contents and results are as follows:1. Uniform particle size distribution of silica nanoparticles preparation and surface modification. With ammonia, water, ethanol, tetraethyl orthosilicate as reaction system, through the precise control of dosage of all kinds of raw materials, preparation of the size of the uniform particle size of silica nanoparticles in around 100 nm. Use appropriate mole ratio of 3-mercapto propyltrimethoxysilane on silica surface modification, using hydrolysis and condensation reaction, modified silica nanoparticles surface evenly on a layer of thiol functional groups.2. The preparation of SiO2, SiO2@Ag, SiO2@Au, SiO2@Fe3O4 composite nanostructures. In the surface modification of silica nanoparticles as a base, in the uniform deposition of silver, gold and ferroferric oxide nanoparticles, surface modification is the key factor for the preparation of such composite nanostructures. Precious metal of silver and gold nanoparticles was preparation after sodium borohydride reduction and ferroferric oxide was synthesis nanoparticles by coprecipitation method under the participation of ammonia. The preparation method is simple and neat, the morphology of the composite nanostructure controllable, and uniform and controllable size nanoparticles dispersion on the surface, with high robustness and connected to the base of silicon dioxide.3. The performance study of gold catalyst and SiO2@Au catalyst. Gold catalysts obtaining two different particle size of 5 nm and 10 nm was prepared, and the preparation of the two different basal ratio of SiO2@Au catalysts. Results show that SiO2@Au than gold catalyst showed higher catalytic activity, the appropriate base amount of SiO2 is the key of the Au catalysts with high catalytic activity. This is because, the existence of the basement can get no surface ligand gold nanoparticles of small size, high surface energy and interface make it has high catalytic activity, and the composite structure in the cyclic catalytic experiments can also showed high activity.4. The synthesis of SiO2@AgCl and SiO2@Ag3PO4 composite nanostructures, and study its photocatalytic performance of rhodamine B under ultraviolet. First the SiO2@Ag on the surface of the silver nanoparticles for the growth of the size, using silver nanoparticles with large size of SiO2 composite structure to the preparation of SiO2@Ag3PO4 and SiO2@AgCl light-catalyst, this method is a method worth studying. Experiments show that this kind of catalytic-materials having excellent performance under UV irradiation, and SiO2@Ag3PO4 than SiO2@AgCl photocatalytic performance.5. The synthesis of two different structure single-core or multi-core Ag@SiO2 composite nanostructures. Using the reductant of tannins to preparation of silver and the gold nanoparticles, regulate the pH value of reaction system, two different sizes of silver nanoparticles, but only can get one size of gold nanoparticles. Due to the diversity of the silver nanoparticles size, we use the silica to assemble silver nanoparticles, adding tetraethyl orthosilicate steps according to the reaction process of precise control, preparation of the single-core or multi-core two different kinds of composite structure. At last, the surface modification and assembly of annin modification silver nanoparticles using L-arginine and silicon dioxide.