1, improving strength and elongation. Epoxy resin is a basic resin material. Adding fumed silica to epoxy resin is completely different from adding coarse silica (silica, etc.) to epoxy resin-based composites. ) in structure. Coarse silica is generally added as a reinforcing agent, which is mainly distributed in the chain of polymer materials. However, fumed silica shows strong activity because of its serious surface coordination deficiency, huge specific surface area and surface hypoxia. It is easy to combine with the oxygen of epoxy cyclic molecules, which improves the intermolecular binding force. At the same time, some fumed silica particles are still distributed in the gaps of polymer chains, showing higher ripples compared with coarse silica particles, thus greatly improving the strength, toughness and ductility of epoxy resin materials added with fumed silica.
2. Improve the wear resistance and smoothness of the material surface. The particles of fumed silica are smaller than that of silica 100- 1000 times. Adding fumed silica to 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 denser and cleaner, the friction coefficient is smaller, and the high strength of nanoparticles greatly enhances the wear resistance of the material.
3. Anti-aging performance. A fatal weakness of epoxy resin matrix composites in the process of use is poor aging resistance, which is mainly due to the medium wave and long wave action of ultraviolet rays in 280-400 nm band radiated by the sun, which has a very serious destructive effect on resin matrix composites, and the degradation of polymer chains leads to the rapid aging of resin matrix composites. Fumed silica can strongly reflect ultraviolet rays, and its addition to epoxy resin can greatly reduce the degradation of epoxy resin by ultraviolet rays, thus achieving the purpose of delaying the aging of materials. China is a big producer and consumer of coatings, but at present, domestic coatings generally have shortcomings such as poor suspension stability, poor thixotropy, poor weather resistance and poor washing resistance, which leads to the need to import a large number of high-quality coatings every year. Some coating manufacturers in Shanghai, Beijing, Hangzhou, Ningbo and other places dare to innovate and successfully realize the application of fumed silica in coatings. This nano-modified coating has changed the shortcomings of previous products, and the main performance indexes have been greatly improved except contrast. For example, the washability of exterior wall coatings has been improved from 1000 to 10000. The artificial accelerated weathering and artificial radiation exposure aging time increased from 250 hours (pulverization 1, discoloration 2) to 600 hours (no pulverization, no discoloration of paint film, color difference value of 4.8). In addition, the bonding strength between the paint film and the wall is greatly improved, the hardness of the paint film is significantly increased, and the surface self-cleaning ability is also improved.
Verb (abbreviation of verb) rubber
Rubber is an excellent elastic body, but its comprehensive performance is not satisfactory. In the process of producing rubber products, it is usually necessary to add carbon black to the rubber compound to improve its strength, wear resistance and aging resistance. However, due to the addition of carbon black, the product is all black and the grade is not high. The advent of fumed silica in China laid a material foundation for the production of a new generation of rubber products with novel colors and excellent properties. After adding a small amount of fumed silica to ordinary rubber, the strength, wear resistance and aging resistance of the product reach or exceed those of high-grade rubber products, and the color can remain unchanged for a long time. The wear resistance, tensile strength, bending strength and aging resistance of nano-modified color EPDM waterproofing membrane are obviously improved, with bright colors and excellent color retention effect. The development of colored tires has also made some progress. If the bending performance of sidewall rubber is improved from 654.38+10,000 times to more than 500,000 times, it is expected to realize the colorization of domestic automobile and motorcycle tires in the near future. 1, Application in Optical Field Nanoparticles are used as infrared reflective materials, mainly made into thin films and multilayer films. Nano-particle film materials have a good application prospect in the light bulb industry. High-pressure sodium lamps and iodine arc lamps for photography and video recording all need strong illumination, but 69% of the energy after filament heating is converted into infrared rays, which shows that a considerable part of electric energy is converted into heat energy and consumed, and only a small part is converted into light energy for lighting. At the same time, the heating of the lamp tube will also affect the life of the lamp. How to improve luminous efficiency and increase illumination has always been a key problem to be solved urgently. The birth of nanoparticles provides a new way to solve this problem. Since 1980s, researchers and technicians have made multilayer interference films with nano-Si0X and nano-TiO2 _ 2 particles, with a total thickness of microns, lining the inner wall of the bulb cover. Therefore, it not only has good light transmittance, but also has strong infrared reflection ability. According to experts' calculation, compared with traditional halogen lamps, this lamp can save electricity by 15%.
2. PMMA, a new plexiglass additive, is often used as window material of aircraft. When the plane flies at high altitude, the window material is easy to age due to ultraviolet radiation, which leads to the decrease of transparency. In order to solve this problem, nano-Si0X with surface modification was added in the production process of plexiglass, which made the anti-ultraviolet ability of the produced products more than double and the impact strength increased by 80%.