Preparation
Generally,
aluminum oxide can be divided into three categories, namely, gas phase method, liquid phase method and solid phase method.
Gas phase method
- Laser induced vapor deposition
The laser induced vapor deposition synthesis technology mainly uses a laser to generate a high temperature environment, so that the reactants react in an instant to produce small embryos of ultrafine particles. Then these small embryos will grow up, and when they leave the laser irradiation area, they will be rapidly cooled to stop growing, and the micro-powder will enter the collector, and finally the corresponding treatment will be performed to obtain the nano powder.
- Plasma gas phase synthesis
The aluminum salt oxidizes with air to form an oxide under a plasma gas atmosphere formed between the anode and cathode plates. The product is then rapidly cooled to form fine particles, nano alumina. Finally, collect it.
- Chemical vapor deposition
Chemical gas phase deposition is the condition that aluminum chloride is much higher than the critical reaction temperature.
The reactant vapor forms a high saturated vapor pressure, automatically condenses to form a large number of crystal nuclei, and the generated solid matter is deposited on the surface of the heated solid substrate, and finally the nano alumina is obtained in the collection chamber.
Liquid phase method
The most commonly used method for synthesizing nano-alumina particles is the liquid phase method, also known as wet chemical method. The liquid phase method can be further divided into a precipitation method, a sol-gel method, and the like.
Solid phase method
Mechanical grinding
The mechanical grinding method is a simple and low-cost method for preparing nano alumina. The raw material (such as kaolin) is directly ground in a grinder, and then the nano-aluminum oxide powder is obtained by a process of removing impurities. The disadvantage of this method is that the size of the powder obtained is different in size and noise during production.
Chemical pyrolysis
- Ammonium aluminum sulfate pyrolysis
First, the aluminum ammonium sulfate is subjected to multiple purifications and then decomposed by heating to obtain nano alumina. During the preparation process, some harmful gases (such as sulfur trioxide gas) may be generated, which may cause environmental pollution.
- Ammonium aluminum carbonate thermal decomposition
This method is an improvement of the ammonium aluminum sulfate pyrolysis method, which saves many times.
Application
In addition to the basic properties of nanomaterials, nano-alumina exhibits a series of excellent properties in some aspects, and has been widely concerned in ceramics and anti-corrosion of materials, and has been widely used.
Ceramic material
Alumina ceramics have good comprehensive properties in terms of mechanics, high temperature resistance and chemical stability. It is one of the most widely used ceramic materials in the world. Nano-scale alumina can improve the strength, toughness and superplasticity of materials. The performance of the material is greatly improved.
Material surface protection
Nano alumina has its own special properties, which can significantly improve the surface properties of the material and provide surface protection.
Polymer modification
Since nano-alumina has developed rapidly in recent years, polymers have been modified and widely used. Modification of different polymers to meet the requirements of use.
Composite material
Due to the characteristics of nano alumina itself, it plays an important role in composite materials, such as dispersion strengthening.
Adsorbent material
Nano alumina also has some applications in the adsorption of metal ions.
Application in sensors
The sensor's nano-alumina film was used to detect the release of nitric oxide from mice, and the results were satisfactory, indicating that there may be practical applications in the nitric oxide monitoring system.
Catalyst and carrier applications
Nano alumina also has important applications in the abrasives industry, and some nano-scale composite abrasives can be prepared for precision grinding.
TRUNNANO (Luoyang Trunnano Tech Co., Ltd ) is a professional aluminum oxide manufacturer with over 12 years experience in chemical products research and development. If you are looking for high quality aluminum oxide please feel free to contact us and send an inquiry.
