Abstract: With the rapid development of nanotechnology, the excellent performance of nanomaterials has been gradually applied to the coating industry, this paper mainly introduces the main application status of nano-coatings at home and abroad, as well as the important and difficult problems in the process of nano-modified coatings research and the current solutions, to share some examples of nano-materials in the research of corrosion-resistant coatings.
At present, the development of nano-coatings in China is still relatively backward compared with developed countries, which needs to be explored in depth by researchers.
Paint coating anti-corrosion technology has long played a very important role in the national economy as a simple and convenient anti-corrosion method.
As nanotechnology began to penetrate into various fields, the application of nanomaterials in coating research has been increasingly emphasized.
The surface effect, volume effect, quantum size effect and macroscopic quantum tunneling effect of nanoparticles are utilized to improve various aspects of coatings, enhance their hardness and oxidation resistance, and make them photocatalytic, antimicrobial, electromagnetic wave absorbing, heterochromatic with angle, and affinity to water and oil.
Many enterprises and research institutions at home and abroad have done a lot of work on nano-modified coatings and achieved promising results.
This paper discusses the important and difficult problems in the research process of nano-modified coatings and the current solutions, and focuses on the research examples of nano-materials in anti-corrosion coatings, with a view to providing some references for the related research on the combination of nanotechnology and coatings.
1 Foreign nanocoatings research, application status
The application of nanomaterials mainly includes two aspects: one is to add nanomaterials to some traditional materials to further improve the performance of traditional materials;
The second is to make nano-materials into nano-solid materials through molding process. Currently, the first technology is more common and mature.
Nanophase Technologies mixes its own nanomaterial product, NanoTek alumina, with clear varnish to produce a clear coating that is 24 times more abrasion resistant than traditional coatings.
SDC Coatings directly nanosized SiO2 and nano-metal oxide sol for wear-resistant transparent coatings SILVUE series of products, can be anti-ultraviolet, anti-fogging, has been successfully used in automobiles, airplanes, buildings, etc., glass windows and other transparency and abrasion-resistant requirements of the high, environmentally demanding places.
Another successful example of foreign use of inorganic nanomaterials in coatings is limousine top coat. The nano TiO2 is mixed with aluminum powder Pigment or mica pearlescent pigment and added into the paint, and its coating has heterochromaticity with angle, which increases the fullness of the metal color and the perspective flash color.
In addition, nanoparticles have strong absorption of ultraviolet rays, such as the addition of TiO2, SiO2 and other nanoparticles in exterior architectural coatings can improve the weathering resistance of coatings.
Nano ZnO is a good photocatalyst, under the irradiation of ultraviolet light, it can decompose organic substances and play the role of antibacterial and deodorization.
Foreign countries also use nanometer ultrafine powder size is very small, the different wavelengths of radar waves and infrared radiation has a super absorption effect of the characteristics of the nanoscale carbonyl iron powder, nickel powder, ferrite powder successfully formulated military stealth coatings.
Coating to aircraft, warships, missiles, submarines and other weapons and equipment, so that it has stealth performance, is expected to be in the future military stealth in a big way.
Some of the semiconductor characteristics of the nanoparticles of oxides, at room temperature than conventional oxides have high conductive properties, Japan's Panasonic has developed a good electrostatic shielding nanocomposite coatings, the use of nanoparticles FeO, TiO2, ZnO and so on.
2 Domestic research and application of nano-coatings
Most of the domestic research and development of nano-coatings have just started, mainly focusing on improving the weather resistance of architectural exterior coatings and antibacterial properties of interior coatings, while the research and development and industrialization of industrial coatings, aerospace coatings and functional coatings lag behind the developed countries.
China's first generation of nano-titanium coatings were successfully developed in Harbin, which is used in the anti-corrosion coating of steel for marine use, and can guarantee ten years of excellent anti-corrosion effect.
In recent years, some researchers have begun to deeper quantitative research on the specific role of nanoparticles in improving the performance of coatings, including the optimization principle, nanoparticle particle size, adding ratio and so on.
Zhang Xiuzhi et al. of the Institute of Metals, Chinese Academy of Sciences, for the corrosion and fouling in the marine environment, conducted research on nano-modified epoxy coal tar pitch coatings.
Using the physical method of grinding combined with the chemical method of adding surface modifiers in the epoxy coal tar pitch 0%, 5%, 10%, 20% titanium nanopowder, titanium nanopowder to study the corrosion resistance of epoxy coal tar pitch coating. The results show that the coating containing 10% (by weight) of titanium nanopowder has the best protective performance.
Zeng Zhen-Ou et al. from South China University of Technology prepared nano TiO2 coatings on the surface of 304 stainless steel and mild steel, and then added SnO2 to prepare nano TiO2-SnO2 composite coatings and stacked coatings, and found that nano TiO2-SnO2/TiO2 coatings had better photocathodic protection and corrosion protection for mild steel than nano TiO2 coatings.
Tian Huiwen et al. from Institute of Oceanography, Chinese Academy of Sciences used electrochemical impedance spectroscopy (EIS) to study the corrosion pattern of nano-Si02 modified epoxy coatings in 3.5% NaCl (mass fraction) aqueous solution, and found that the addition of nano-Si02 can significantly improve the corrosion protection performance of the coatings, and the best corrosion protection performance was achieved when the mass fraction added was 2%.
Beijing University of Chemical Technology, Xie Shuangying et al. will be nano-TiO2 to mechanical stirring way to add to the epoxy zinc-rich coatings, the preparation of nano-TiO2 modified epoxy zinc-rich coatings, found that the surface of weathering steel coated with nano-TiO2 modified epoxy zinc-rich coatings, its self-corrosion current is reduced, and the degree of surface corrosion is reduced.
Zhejiang University proposed a surface in-situ nano-modification preparation method for nano-coatings and prepared high-performance nano-coatings.
Xiamen University and Xiamen Daping Industry and Trade Co., Ltd. research and development of tunnel fireproof coating, the preparation of key technologies and functional surface treatment of nano-coatings project, applied for two national invention patents.
Some coating enterprises in China have also made contributions to the development of nano-coatings, Changchun New Century Nanotechnology Research Institute, Century Nanotechnology Co. This has played a good role in promoting the technological progress of nano-coatings and the expansion of application fields in China.
