Expanded graphite, also known as flexible graphite or worm graphite, is a new type of carbon material. Expanded graphite has many advantages such as large specific surface area, high surface activity, good chemical stability and high temperature resistance. The commonly used preparation process of expanded graphite is to use natural flake graphite as a material, first to generate expandable graphite through an oxidation process, and then to expand into expanded graphite. The following editors of Furuite Graphite explain the preparation and practical application of expanded graphite:
1. Preparation method of expanded graphite
Most of the expanded graphite uses chemical oxidation and electrochemical oxidation. The traditional chemical oxidation method is simple in process and stable in quality, but there are problems such as waste of acid solution and high sulfur content in the product. The electrochemical method does not use an oxidant, and the acid solution can be recycled and reused many times, with little environmental pollution and low cost, but the yield is low, and the requirements for electrode materials are relatively high. Currently, it is limited to laboratory research. Except for the different oxidation methods, the post-treatments such as deacidification, water washing and drying are the same for these two methods. Among them, the chemical oxidation method is the most widely used method so far, and the technology is mature and has been widely promoted and applied in the industry.
2. Practical application fields of expanded graphite
1. Application of medical materials
Medical dressings made of expanded graphite can replace most traditional gauze due to their many excellent properties.
2. Application of military materials
Pulverizing expanded graphite into micropowder has strong scattering and absorption properties for infrared waves, and making its micropowder into an excellent infrared shielding material plays an important role in optoelectronic confrontation in modern warfare.
3. Application of environmental protection materials
Because expanded graphite has the characteristics of low density, non-toxic, non-polluting, easy to handle, etc., and also has excellent adsorption, it has a wide range of applications in the field of environmental protection.
4. Biomedical materials
Carbon materials have excellent compatibility with the human body and are a good biomedical material. As a new type of carbon material, expanded graphite materials have excellent adsorption properties for organic and biological macromolecules, and have good biocompatibility. , non-toxic, tasteless, no side effects, has a wide range of application prospects in biomedical materials.
The expanded graphite material can instantly expand 150~300 times in volume when exposed to high temperature, changing from flake to worm-like, resulting in a loose structure, porous and curved, enlarged surface area, improved surface energy, and enhanced ability to adsorb flake graphite. The worm-like graphite can be self-fitted, so that the material has the functions of flame retardant, sealing, adsorption, etc., and has a wide range of applications in the fields of life, military, environmental protection, and chemical industry.
Post time: Jun-01-2022