Expandable Graphite
Size
0.50mm or 0.106mm, etc
Package
25 kg small bags into ton bags
Origin
China
Features
Preservative/Electrical and thermal conductivity, etc.
Application
Fireproof sealing element, flame retardant, refractory brick, etc.
Expandable graphite crystal is a typical layered carbon material. Other heterogeneous particles such as atoms, molecules, ions, and even atomic clusters are inserted into the interlayer of crystalline graphite by physical or chemical methods to form a new layered compound, which is called graphite interlayer compound, namely expandable graphite.
Request a quoteExpandable graphite is an important industrial raw material for producing flexible graphite sheets, which are widely used as gaskets, seals, thermal insulators, etc. Franli Company uses natural graphite with different particle sizes to prepare expandable graphite, and understands the performance advantages of expandable graphite by studying the expansion mechanism of expandable graphite and the temperature difference.It has been reported that the particle size of natural graphite affects the structure of expanded graphite, and this effect is related to the expansion mechanism of expandable graphite prepared from natural graphite with different particle sizes.
Expandable graphite at room temperature
At room temperature, three particle sizes of natural graphite (80, 50, and 35 mesh, denoted as NG80, NG50, NG35, respectively), concentrated sulfuric acid (98%) and hydrogen peroxide (30%) (graphite: sulfuric acid: hydrogen peroxide) = 6g: 10ml: 1. 5ml), keep the reaction for 90min, wash with water to pH 5-7, and dry to form expandable graphite. The expandable graphite was heated in a microwave oven at 280 W for 40 s to obtain three kinds of expanded graphite, which were denoted as EG80, EG50 and EG35, respectively. It can be seen that the expanded graphite formed from large particle natural graphite has higher expansion volume, mass loss rate and expansion rate.
High temperature heating expandable graphite
Expandable graphite is usually prepared by rapid heating at a high temperature in a high-temperature furnace. Recently, some factories have prepared expandable graphite by expanding it in a microwave oven. Heating the expandable graphite at high temperature causes the intercalation volume between the graphite layers to increase dramatically by a factor of 1000, resulting in a high pressure. As the expandable graphite particles decrease, the gas has more leakage paths. Instantaneous gas leakage lowers the decomposition pressure and thus the overrun rate. In addition, the thickness of the graphite flakes also has a significant effect on the expansion ratio. Thick graphite flakes will expand more fully scaled than thin graphite flakes, and thin graphite flakes reduce the expansion potential.
Applications of expandable graphite
(1) Sealing industry: Compared with traditional sealing materials such as asbestos rubber, it has excellent properties such as good compressibility, resilience, self-adhesion and low density, and can be used for a long time under harsh conditions such as high temperature and corrosion. use. The graphite sheets and sealing components made of it are widely used in aerospace, machinery, electronics, nuclear energy, petrochemical, electric power, shipbuilding, smelting and other industries.
(2) Environmental protection field: expandable graphite obtained by high temperature expansion has rich pore structure, and because it is a promising environmental protection material for removing oil pollution on water surface. In the wastewater treatment of chemical enterprises, microorganisms (bacteria) are often used for treatment. expandable graphite is a good microbial carrier, especially in the treatment of water contaminated by oily organic macromolecules. Regeneration and reuse, so it has a good application prospect.
(3) Medical field: Because expandable graphite has excellent adsorption properties, it has a wide range of uses in environmental protection and biomedicine. Due to the adsorption properties of organic and biological macromolecules, expandable graphite has broad application prospects in biomedical materials.
Franli factory research found that the expansion rate of expandable graphite increases with the increase of natural graphite particle size, which is closely related to the expansion mechanism of expandable graphite. As the graphite particles become smaller, the relative leakage of gas between graphite layers will increase when heated at high temperature, reducing the decomposition pressure required for graphite expansion. This high pressure causes the decomposition of the graphite flakes and the vigorous expansion of the expandable graphite. The Franli factory is constantly researching different varieties of expandable graphite to replace high-priced metal materials and save costs.
