The characteristics of nanomaterials have laid the foundation for its wide application. Using nanomaterials’ special anti-ultraviolet, anti-aging, high strength and toughness, good electrostatic shielding effect, color changing effect and antibacterial and deodorizing function, the development and preparation of new types of automobiles coatings, nano-composite car bodies, nano-engine and nano-automotive lubricants, and exhaust gas purifiers have broad application and development prospects.
When the materials are controlled to the nanoscale, they own not only light, electricity, heat, and magnetism change, but also many new properties such as radiation, absorption. This is because the surface activity of nanomaterials increase with the miniaturization of particles. Nanomaterials can be seen in many parts of the car, such as chassis, tires or car body. Until now, how to effectively use nanotechnology to achieve the rapid development of cars is still one of the most concerned issues in the automotive industry.
Main application directions of nanomaterials in automobile research and development
1. Automotive coatings
The application of nanotechnology in automotive coatings can be divided into multiple directions, including nano topcoats, collision-color-changing coatings, anti-stone-strike coatings, anti-static coatings, and deodorizing coatings.
(1) Car topcoat
The topcoat is an intuitive evaluation of the quality of the car. A good car topcoat should not only have excellent decorative properties, but also have excellent durability, that is, it must be able to resist ultraviolet rays, moisture, acid rain and anti-scratch and other properties
In nano topcoats, nanoparticles are dispersed in the organic polymer framework, acting as load-bearing fillers, interacting with the framework material and helping to improve the toughness and other mechanical properties of the materials. Studies have shown that dispersing 10% of nano TiO2 particles in the resin can improve its mechanical properties, especially the scratch resistance. When nano kaolin is used as filler, the composite material is not only transparent, but also has the characteristics of absorbing ultraviolet rays and higher thermal stability.
In addition, nanomaterials also have the effect of changing color with the angle. Adding nano titanium dioxide (TiO2) to the metallic glitter finish of the car can make the coating produce rich and unpredictable color effects. When nanopowders and flash aluminum powder or mica pearlescent powder pigment are used in the coating system, they can reflect blue opalescence in the photometric area of the light-emitting area of the coating, thereby increasing the fullness of the color of the metal finish and producing a unique visual effect.
Adding Nano TiO2 to Automotive Metallic Glitter Finishes-Collision color changing paint
At present, the paint on the car does not change significantly when it encounters a collision, and it is easy to leave hidden dangers because no internal trauma is found. The inside of the paint contains microcapsules filled with dyes, which will rupture when subjected to a strong external force, causing the color of the impacted part to change immediately to remind people to pay attention.
(2) Anti-stone chipping coating
The car body is the part closest to the ground, and is often impacted by various splashed gravel and rubble, so it is necessary to use a protective coating with anti-stone impact. Adding nano alumina (Al2O3), nano silica(SiO2) and other powders to automotive coatings can improve the surface strength of the coating, improve wear resistance, and reduce the damage caused by gravel to the car body.
(3) Antistatic coating
Since static electricity can cause many troubles, the development and application of antistatic coatings for automotive interior parts coatings and plastic parts are increasingly widespread. A Japanese company has developed a crack-free antistatic transparent coating for automotive plastic parts. In the US, nanomaterials such as SiO2 and TiO2 can be combined with resins as electrostatic shielding coatings.
(4) Deodorant paint
New cars usually have peculiar smells, mainly volatile substances contained in resin additives in automotive decorative materials. Nanomaterials have very strong antibacterial, deodorizing, adsorption and other functions, so some nanoparticles can be used as carriers to adsorb relevant antibacterial ions, thereby forming deodorizing coatings to achieve sterilization and antibacterial purposes.
2. Car paint
Once the car paint peels and ages, it will greatly affect the aesthetics of the car, and aging is difficult to control. There are various factors that affect the aging of car paint, and the most important one should belong to the ultraviolet rays in sunlight.
Ultraviolet rays can easily cause the molecular chain of the material to break, which will cause the material properties to age, so that the polymer plastics and organic coatings are prone to ageing. Because uv rays will cause the film-forming substance in the coating, that is, the molecular chain, to break, generating very active free radicals, which will cause the entire film-forming substance molecular chain to decompose, and finally cause the coating to age and deteriorate.
For organic coatings, because ultraviolet rays are extremely aggressive, if they can be avoided, the aging resistance of baking paints can be greatly improved. At present, the material with the most UV shielding effect is nano TIO2 powder, which shields UV mainly by scattering. It can be deduced from theory that the particle size of the material is between 65 and 130 nm, which has the best effect on UV scattering. .
3. Auto Tyre
In the production of automobile tire rubber, powders such as carbon black and silica are needed as reinforcing fillers and accelerators for rubber. Carbon black is the main reinforcing agent of rubber. Generally speaking, the smaller the particle size and the larger the specific surface area, the better the reinforcing performance of carbon black. Moreover, nanostructured carbon black, which is used in tire treads, has low rolling resistance, high wear resistance and wet skid resistance compared with the original carbon black, and is a promising high-performance carbon black for tire treads.
Nano Silica is an environmentally friendly additive with excellent performance. It has super adhesion, tear resistance, heat resistance and anti-aging properties, and can improve the wet traction performance and wet braking performance of tires. Silica is used in colored rubber products to replace carbon black for reinforcement to meet the needs of white or translucent products. At the same time, it can also replace part of carbon black in black rubber products to obtain high-quality rubber products, such as off-road tires, engineering tires, radial tires, etc. The smaller the particle size of silica, the greater its surface activity and the higher the binder content. The commonly used silica particle size ranges from 1 to 110 nm.