Interpretation of powder characterization by Dr. Zhong Hua, American instrument

For different application fields, the characteristics of the powder are not the same, and the measurement method is difficult to describe in detail. In order to help the powder industry practitioners to understand more deeply the techniques of powder characterization, the “2017 Second National Powder Testing and Evaluation Technology Application Conference and Practical Training Course” will be held on December 27-29 this year. Zhuhai City, Guangdong Province was held in a grand ceremony. Dr. Zhong Hua, Marketing Application Manager of McMurray (Shanghai) Instrument Co., Ltd., will also be invited to share a report entitled “Comprehensive Understanding of the Means and Application Practices of Powder Characterization”. We look forward to communicating with you in the event and discussing the means and application development to promote the characterization of powder.

The characteristics of the powder include the physical properties of the particles and the physical properties of the aggregate of particles, which mainly include the following aspects: 1. Geometrical properties (specific surface and porosity, pore size and pore size distribution, pore volume, etc.); 2. Physical properties (true density) , bulk density, skeletal density, etc.); 3. surface properties (surface activity, surface acidity, etc.); 4. mechanical properties (compressibility, formability, fluidity, etc.). These characteristics will affect the molding process and later application of the powder to some extent. Therefore, in the production and research process, it is necessary to use appropriate means to accurately determine the material characterization.

In this paper, the characterization methods of the specific surface area and porosity, physical properties, surface properties and mechanical properties of inorganic powder materials are briefly analyzed.

1, specific surface area and pore size

The specific surface area and pore size are physical properties that affect the quality and performance of solid materials. Based on the change in physical surface area of ​​the two materials, materials of the same physical size will also exhibit completely different performance. Specific surface area measurement is an important analytical method for catalysts, molecular sieves, MOF materials, batteries, adsorbents, artificial bones, pharmaceuticals, metal powders for additive manufacturing and a wide variety of other applications and industries.

The physical adsorption principle can be used to determine the adsorption amount of the powder on the gas (or liquid vapor), thereby obtaining the specific surface area and pore structure information of the material, which is the most commonly used method for characterizing microporous and mesoporous materials. Physical adsorption has a wide range of applications in the chemical industry, petroleum processing industry, agriculture, pharmaceutical industry, environmental protection and other fields.

Analytical means: gas adsorption method

ASAP 2020 Plus Series Fully Automatic Surface and Porosity Analyzer (Gas Adsorber)

2, surface characteristics

For the structural design and performance optimization of the catalyst, an in-depth understanding of the specific surface and surface chemistry of the catalytic material is required. The chemisorption method is used to determine the efficiency of a catalyst to promote an ideal reaction, and to detect degradation of catalytic activity/regeneration over a period of time. Chemical adsorption is the result of a chemical bond between the surface of the powder and the adsorbate and is often used to study the nature of the active site of the catalyst. The interaction between the active site and the carrier and the determination of the dispersity of the supported metal, the surface area of ​​the metal or the particle size, and the like.

Analytical methods: chemisorption analysis methods, including static volumetric methods and dynamic (flowing gas) techniques

3, density test

The density of the powder refers to the mass of the powder per unit volume. The powder has certain flow characteristics, and the density of the powder has a great influence on the fluidity of the powder. Therefore, the density of the powder is studied, which is of great significance for powder processing, transportation, packaging and storage. The density of the powder is divided into true density, skeleton density, and bulk density depending on the volume indicated.

Analytical means: gas replacement method

AccuPyc II 1340 Series Automatic Gas Displacement True Density Meter

4, mercury intrusion test

Mercury intrusion, also known as mercury porosimetry, is based on the fact that mercury is not wet to the general solids and that the interfacial tension resists entry into the pores. External pressure must be applied to allow mercury to enter the pores. Mercury intrusion can obtain many important physical properties of some mesoporous and macroporous powders, such as pore structure information (pore size, pore volume, pore area, etc.), porosity, tortuosity, permeability, compressibility, pore-throat ratio, Fractal dimensions, etc.

Analytical means: mercury intrusion method

AutoPore V Series High Performance Automatic Mercury Injector

Mike Instruments

Mike Instruments is the first company in the world to bring an automatic surface area analyzer, a mercury intrusion meter, and a sedimentation particle size analyzer to market. Since its inception in 1962, Mike Instruments has been at the forefront and innovation of technology research in many fields in terms of specific surface area and porosity analysis, mercury intrusion analysis techniques, various density tests, chemisorption analysis and microcatalytic reactions. Maintaining a world-leading position in the field of fine particle analytical instruments.

American Mike Instruments products entered the Chinese market in 1979 and became the earliest analytical instrument to enter the Chinese market after the establishment of diplomatic relations between China and the United States. After serving Chinese users for more than 30 years, McMurray (Shanghai) Instrument Co., Ltd. was established in Shanghai in March 2011, specializing in providing products for American Micro Instruments for the Chinese market. The company is headquartered in Shanghai, with offices in Beijing and Guangzhou, and an application laboratory to provide demonstration and operation training for various instruments and provide external sample services to provide complete laboratory solutions and problems for users. Analysis of the sample.

Part of the content is transferred from the powder circle

Manual Nursing Bed

Manual Nursing Bed,Single Crank Nursing Bed,Back Lifting Medical Bed,Clinical Caring Manual Bed

Jiangmen Jia Mei Medical Products Co.,Ltd. , https://www.jmjiameimedical.com