The nano raw materials used in the coating field are mainly divided into the following categories according to their functions: Photocatalytic nano-coatings, weather-resistant nano-coatings, high-mechanical properties nano-coatings, transparent heat-insulating nano-coatings, and conductive nano-coatings.
1.Photocatalytic Nanocoatings
Using the photocatalytic properties of Titanium dioxide nanoparticles, scientists have already carried out the protection of historical building relics. The researchers took advantage of the wide catalytic properties of nano-TIO2 that most of the Ca(OH)2 in the layer reacted with SO2 oxidized by OH to form CaSO4, which prevented the further erosion of buildings by SO2 and CO2 in the air, and effectively protected historical buildings. remains. In the application of photocatalytic decontamination and sterilization, CUxO/TIO2 nanocomposite products that can absorb visible light have been applied indoors.
2. Weather resistant nano coating
The high-energy damage of ultraviolet rays is the main culprit for the degradation and aging of organic matter in coatings. The small size effect of nano materials makes it have a strong absorption effect on ultraviolet rays, and the particle size of nanoparticles is much smaller than the wavelength of visible light, which ensures that the layer has good transparency. At present, the most widely used weather-resistant nano materials are nano-TIO2, ZNO, SIO2. Among them, TIO2 has excellent functions of absorbing, reflecting and scattering ultraviolet rays, so it is an ideal UV protectant. ZNO has good absorption and scattering effect on long-wave ultraviolet. SIO2 has extremely strong reflectivity to medium-wave and long-wave ultraviolet rays, and it can play a better shielding effect when added to coatings. Weather-resistant nano-coatings are widely used in building materials, cosmetics and art protection.
3. Nano coating with high mechanical properties
The characteristics of the filler directly determine the function and performance of the coating. The contact area between the nanoparticles and the organic matter in the coating is huge, and the bonding force is strong, which increases the mechanical properties of the organic layer, such as the hardness, impact resistance and wear resistance of the coating.
Research indicates that addition of nano-AL2O3, TIO2, SIO2, ZNO and other particles into coatings can significantly enhance the anti-scratch and wear-resistant properties of the coatings. This is widely used in automotive topcoats, furniture paints, lens complaints and other fields.
4. Transparent heat-insulating nano-coating
Nano metal oxide particles are selective to the solar spectrum and are ideal filler particles for nano coatings. Nano ATO tin antimony oxide, nano ITO indium tin oxide and nano zinc aluminum oxide have good barrier properties for near infrared. Nano TIO2, ZNO, FE2O3, etc. have a good barrier to ultraviolet rays. Evenly dispersing such nano-oxide particles into an organic solution can prepare nano-composite transparent thermal insulation coatings, which has a huge promotion effect on building energy conservation, emission reduction and environmental protection advocated by the state.
5. Conductive Nanocoatings
At present, nanoparticles such as nano-ATO, SNO2, TIO2, ZNO, FE2O3 have been used in electrostatic shielding nanocomposite coatings. The fillers are in contact with each other to form a conductive network, and the carriers move freely in the conductive network.
Another popular conductive material in the market is nano AZO, which is doped with Al2O3 in ZnO, has high temperature resistance, good electrical conductivity, strong high temperature stability and good radiation resistance. The product is a relatively cheap, cost-effective and environmentally friendly.