Gas phase application of silica Fumed silica is one of the most important high-tech ultra-fine inorganic new materials. Because of its small particle size, it has large specific surface area, strong surface adsorption, large surface energy, high chemical purity, good dispersion performance, thermal resistance, Resistance and other aspects have specific properties. With its superior stability, reinforcement, thickening and thixotropy, it has unique characteristics in many disciplines and fields and has an irreplaceable role. Fumed silica, commonly known as "nano silica", is widely used in various industries as additives, catalyst carriers, petrochemicals, decolorizers, matting agents, rubber reinforcing agents, plastic fillers, ink thickeners, metal soft abrasives Lighting agent, insulating and insulating filler, advanced daily cosmetic filler and spraying material, medicine, environmental protection and other fields. And it provides a new material basis and technical guarantee for the development of related industrial fields. It has attracted great attention due to its specific functions compared with conventional materials in terms of magnetism, catalysis, light absorption, thermal resistance and melting point. The following is the application of fumed silica in various industries. Resin-based composite materials have the characteristics of light weight, high strength and corrosion resistance. However, the current material industry and the pillar industries of the national economy have higher and higher requirements for the performance of resin-based materials. How to The synthesis of high-performance resin matrix composites has become an important topic in the current material and business circles. The advent of fumed silica provides a new opportunity for the synthesis of resin-based composite materials and a new way for the modification of traditional resin-based materials, as long as the fumed silica particles can be fully and uniformly dispersed into the resin Among the materials, the purpose of comprehensively improving the performance of resin-based materials can be achieved.
1. Improve strength and elongation. Epoxy resin is the basic resin material. Adding fumed silica to epoxy resin is completely different in structure from the epoxy resin-based composite material added by coarse-crystalline silica (silica, etc.). Coarse-crystalline SiO2 Generally added as a reinforcing agent, it is mainly distributed in the chain of polymer materials, and fumed silica has the characteristics of serious lack of coordination on the surface, huge specific surface area and lack of oxygen on the surface, which makes it show extremely strong performance. Active, it is easy to bond with the oxygen of epoxy cyclic molecules, which improves the bonding force between molecules. In comparison, it shows high flowability, so that the strength, toughness and ductility of epoxy resin materials added with fumed silica are greatly improved.
2. Improve wear resistance and improve the surface finish of the material. The fumed silica particles are 100-1000 times smaller than SiO2, and adding it to the epoxy resin is beneficial to wire drawing. Due to the high fluidity and small size effect of fumed silica, the surface of the material is more compact and clean, the friction coefficient becomes smaller, and the high strength of the nano-particles greatly enhances the wear resistance of the material.
3. Anti-aging properties. A fatal weakness in the use of epoxy resin-based composite materials is the poor anti-aging performance, which is mainly due to the effect of ultraviolet rays in the 280-400nm band of solar radiation, and its damage to resin-based composite materials is very serious. , the degradation of the polymer chain leads to the rapid aging of the resin matrix composites. The fumed silica can strongly reflect ultraviolet rays, and adding it to epoxy resins can greatly reduce the degradation of ultraviolet rays to epoxy resins, thereby achieving the purpose of delaying the aging of materials. 1. Application in the field of optics Nanoparticles are mainly used in infrared reflective materials to be made into thin films and multilayer films. Nanoparticle film materials have good application prospects in the light bulb industry. High-pressure sodium lamps and various iodine arc lamps used for photography and photography all require strong lighting, but 69% of the energy of the filament is converted into infrared light after being heated, which shows that a considerable amount of electrical energy is converted into heat energy and consumed, and only a small amount of energy is consumed. Part of it is converted into light energy for lighting. At the same time, the heat of the lamp tube will also affect the life of the lamp. How to improve the luminous efficiency and increase the illuminance has always been a key problem to be solved urgently. The birth of nanoparticles provides a new way to solve this problem. Since the 1980s, scientific researchers and technicians have used nano-SiOX and nano-TiO2 particles to make a multi-layer interference film with a total thickness of microns, which is lined on the inner wall of the bulb cover. The result is not only good light transmittance, but also strong infrared reflection ability. . According to experts' calculations, under the same light brightness, this kind of lamps can save 15% of electric energy compared with traditional halogen lamps.