New materials- nanomaterials zinc oxide

Introduction to zinc oxide

Zinc oxide is an oxide of zinc. Unsoluble in water, soluble in acids and strong alkali. Zinc oxide is a commonly used chemical additive.

Other name: zinc oxygen powder, zinc white, zinc white powder

chemical reaction:ZnO

Melting point: 1,975℃

Appearance: white solid

Risk symbol: harmful, harmful to the environment

CAS accession number: 1314-13-2

EINECS Number: 215-222-5

Water solubility: insoluble in water

Zinc oxide action

Nano-zinc oxide (ZnO) has a variety of uses and functions, mainly including the following aspects:

Antimicrobial and anti-inflammatory: nano-zinc oxide has antibacterial and anti-inflammatory effects, which can inhibit the growth and reproduction of some bacteria, and has an auxiliary therapeutic effect on skin infection. Moreover, its anti-inflammatory effect alleviates the inflammatory response in tissues by inhibiting the production and release of inflammatory mediators.

Ulv resistance: nano zinc oxide can absorb and scatter ultraviolet light, play the role of sun protection, protect the skin from ultraviolet damage. Its excellent UV-shielding capability enables its wide use in sunscreen cosmetics and UV-resistant materials 12.

Catalysis: nano zinc oxide has extremely high chemical activity and excellent catalytic, can be used to catalyze phoolysis of organic molecules, such as phenol catalytic photolysis and CO hydrogenation direct synthesis of methanol catalyst. Its high surface activity can improve the catalyst selection performance and catalytic efficiency.

Photocatalysis: nano-zinc oxide in photochemistry as a semiconductor material, with photocatalytic activity, can be used to make photocatalytic materials and photolysis of organic matter.

Zinc oxide application:

1. Rubber tire industry, promote the rubber vulcanization, activation and reinforcement, anti-aging, can strengthen the vulcanization process, improve rubber products, wear resistance, crack resistance.

2. Rubber products, mainly used as a rubber tonic agent, to make the rubber have good corrosion resistance, tear resistance, elasticity, elongation.

3. Glass, adding zinc oxide in the glass, can increase the transparency, brightness and tension resistance, can reduce the thermal expansion coefficient.

4. Coating, used in paint with coloring, anti-corrosion, covering, improve the coating mildew and ultraviolet aging performance.

5. Electron, the magnetic material used to make electronic structural components- -ferrite.

6. Phosphorate solution, used for phosphating treatment, in the phosphorate liquid, the performance is stable, dissolved, clear and transparent, so that the phosphorate solution can better play a role of anti-corrosion, anti-aging, metal protection and so on.

7. Ceramics, used for paint, ink, lacquer coloring, printing and dyeing industry printing dyeing agent.

8. Preferred material for the preparation of desulfurizer production and chemical catalysts.

9. Used for zinc reaction and the production of chemical industrial raw materials, such as zinc phosphate, zinc acetate, zinc borate, etc.

10. Chemical fiber textiles: used for viscose fiber, synthetic fiber products, UV-resistant fabrics, antibacterial fabrics, sunshade.

11 used as an astringent, for making ointment and rubber ointment

12. Sunscreen cosmetics series products

Method of zinc oxide production:

The production process of zinc oxide can be divided into indirect zinc oxide, direct zinc oxide and wet zinc oxide.

The direct method takes zinc ore, zinc ash and zinc concentrate as raw materials, through high temperature oxidation roasting and then coal reduction to zinc vapor, zinc vapor and hot air oxidation to zinc oxide. The low purity of the process product is generally between 75% - -95%, and the impurity content is high. Zinc oxide produced by the direct method is usually crystalline in a needle or rod, with coarser particles. The quality of the product is not only related to the process and raw material quality used, but also related to the quality of the raw coal, because the volatile zinc steam is directly polluted by the return of the raw coal combustion products.

Use zinc ash, add the coal and lime according to the technical requirements, mix and crush the broken material, press the ball with coal ball machine, stack and dry the pressed coal ball; smelt the dried coal ball with zinc oxide furnace, after reduction, oxidation and cooling to collect zinc oxide products.

Sand baking: the raw material uses high temperature boiling roasting, its purpose is to maximize the removal of lead, pick, arsenic, sulfur, mercury impurities, to obtain high quality sand baking, and roasting dust purification after the material acid.

Mass ore: mass ore in the zinc oxygen furnace into the cooling powder receiving system after reduction, to get the zinc oxide to be treated, or directly packaged into zinc oxide finished products.

Indirect method: the raw material of zinc oxide is the metal zinc ingot or zinc slag obtained after smelting.: The zinc ingot or galvanized slag made by electrolysis method is placed in the high temperature resistant crucible, heated to 600~700℃ melting, at the temperature of 1000℃ evaporation form zinc steam, the steam is oxidized in the air by oxygen to produce zinc oxide, the oxidation process will emit shining light with the decrease of temperature, then the zinc oxide particles through a cooling transport tube in a dust chamber cyclone separation, the fine particles with cloth bag capture, that is, the finished zinc oxide product. The purity of zinc oxide products produced by indirect process is 99.5% -99.7%. Indirect zinc oxide can be used in rubber, resistor, paint, phosphoide, film, thermal conductivity materials, catalyst, livestock feed, medicine, medical care and other industrial materials. Wet method: although the purity and whiteness of zinc oxide produced by fire method are very high, the particles are coarse and the specific surface area is small. In order to meet the market demand for large specific surface area zinc oxide (active oxidation), the wet zinc oxide production process is developed. Wet production of zinc oxide is a zinc containing material as raw material, first made zinc containing solution, and then precipitated from the purification treatment of zinc containing solution of zinc compounds easily converted into zinc oxide (such as zinc carbonate) precipitation, zinc compounds precipitation by calcined zinc oxide. The wet method can produce active zinc oxide with fine granularity and large specific surface area.

Zinc oxide preservation method:

1. Storage temperature and humidity

Zinc oxide should be stored at room temperature to avoid exposure to too high or too low temperatures. At the same time, the humidity of the storage environment should also need to be controlled within a certain range to avoid the surface condensation or discoloration caused by high humidity. Generally speaking, the most suitable storage humidity is 40%~50%.

2. Avoid contact with air and moisture

Zinc oxide reacts with air and water at room temperature, leading to a decrease in its quality and purity. Therefore, zinc oxide is needed to avoid excessive exposure to excessive air and moisture during storage and can be stored in sealed bags or closed containers.

3. Selection of packaging materials

When selecting packaging materials for storing zinc oxide, it is necessary to preferentially select materials that can effectively isolate air and moisture, such as aluminum foil bags, polyethylene bags, etc. At the same time, the packaging materials should have a certain moisture-proof, shock-proof and anti-static properties to protect the quality and purity of zinc oxide.

4. Selection of the storage environment

In addition to factors such as temperature, humidity and packaging materials, the choice of the storage environment is also very important. In general, to avoid storing zinc oxide in an environment vulnerable to direct sunlight and humidity, it is best to choose a ventilated, dry and dark storage environment.

5. Storage period and regular inspection

The storage period of zinc oxide is generally about one year, and the expired zinc oxide should not continue to be used. In addition, the quality and purity of zinc oxide need to be checked regularly during the storage process, and the quality problems should be dealt with in time.

In conclusion, ZnO storage needs to pay attention to the environmental temperature, humidity, packaging materials, storage environment selection and many other aspects. Choosing the appropriate storage conditions and storage environment can effectively maintain the quality and stability of zinc oxide, and achieve better results in the use process.