Nanometer zinc oxide is a semiconductor catalyst with electronic structure. Under the irradiation of light, when photons with certain energy or photons with energy Eg exceeding the semiconductor band gap are injected into the semiconductor, electrons are excited from the valence band VB to the conduction band CB, leaving holes. The excited conduction band electrons and valence band holes can recombine to eliminate the input energy and heat. The electrons are captured in the surface state of the material, and the valence band electrons jump to the conduction band. The valence band holes seize the hydroxyl electrons in the surrounding environment, turning the hydroxyl into free radicals, which can be used as a strong oxidant to degrade organic matter (or chlorine), killing bacteria and viruses.
Nanometer zinc oxide has large specific surface area, large surface energy and is easy to agglomerate. On the other hand, the surface polarity of nano ZnO is strong, and it is difficult to form a uniform distribution in organic media, which greatly limits its nanotechnology effect. Therefore, the dispersion and surface modification of nano zinc oxide powder become an indispensable treatment method before nano materials are applied to the matrix.
As we all know, zinc oxide is very easy to produce chemical changes with oxygen in the air, resulting in secondary oxidation, so it is necessary to do a good job in sealing during storage. Although the method of sealing is adopted in production and transportation, it is very important to do a good job in sealing the warehouse if the customer has stored a certain amount of zinc oxide. The airtightness of zinc oxide tank shall be maintained regularly.
The production method of nano zinc oxide (VK-J50) is different from that of ordinary zinc oxide. General production methods of zinc oxide include indirect method, direct method and electrothermal method. For example, the common indirect zinc oxide is made from electrolytic zinc ingot after melting, and zinc vapor is made into Zn+02 through air oxidation surface under high temperature, while nano zinc oxide is reflected by magnesium chloride and alkali under ultra-high pressure and high temperature, and is filtered by organic chemical activated carbon to produce nano zinc oxide.
Nanometer zinc oxide is used as filler, additive and brightener of coatings. In addition to the above properties, the excellent sun protection and isolation ability of nano zinc oxide also has significant characteristics in the aging resistance of building coatings.