Carbon Nanotube

Introduction of Expandable Graphite

Expandable graphite is a type of intercalated graphite that has been treated with an acid or other intercalating agent, which causes the graphite to expand or exfoliate when exposed to heat. The treatment inserts molecules between the graphene layers, increasing the distance between them. When heated, these intercalated materials decompose, producing gas that forces the layers apart, leading to a significant increase in volume—often up to 300 times its original size. This property makes expandable graphite useful in a variety of applications where thermal insulation, fire retardancy, and chemical resistance are required.

Features of Expandable Graphite

• Thermal Expansion: Upon heating, typically above 200°C, expandable graphite can dramatically increase in volume.
• Fire Retardant Properties: The expanded form creates a barrier that can help prevent the spread of fire and smoke.
• Chemical Resistance: It is resistant to many chemicals, making it suitable for use in harsh environments.
• Sealing Capability: When expanded, it forms a tight seal that can be used for gaskets and seals.
• Low Density: After expansion, the material becomes very light, which is advantageous for certain applications.
• Flexibility in Formulation: Can be customized with different expansion temperatures and rates by adjusting the intercalation process.

Applications of Expandable Graphite

• Fire Protection: Used in intumescent coatings, fire doors, and other building materials to provide fire protection.
• Gasketing and Sealing: In the form of flexible graphite sheets, it is used as a high-temperature gasket and seal in industrial applications.
• Thermal Insulation: As an effective insulator, it is used in furnace linings, refractory products, and other high-temperature insulation needs.
• Electrical Conductivity: Due to its conductive nature, it can be used in electrical brushes and electrodes.
• Environmental Remediation: Used in oil spill cleanup and water purification due to its ability to absorb contaminants.
• Metallurgy: As a carbon additive in the production of steel and other metals.
• Batteries and Fuel Cells: Can be used as a component in some types of batteries and fuel cells.

About Us

Graphite-corp was founded in 2008 and is a high-tech enterprise specializing in the researching and developing, producting, and sales of graphite materials. Our products include but not limited to Flake Graphite, Expandable Graphite, Spherical Graphite, Graphite Powder, Medium Carbon Flake, High Carbon Flake and High Purity Graphite, etc. If you are interested, please feel free to contact us!(sales@graphite-corp.com)

Payment Term

L/C, T/T, Western Union, Paypal, Credit Card etc.

Shipment Term

By sea, by air, by express, and as customers request.

Storage Conditions

1) Store in a dry environment at room temperature.

2) Avoid damp and high temperature.

3) Use immediately after opening the inner packing bag.

FAQs

Q: How does expandable graphite work?

A: Expandable graphite works through the process of intercalation, where an intercalating agent (usually an acid) is inserted between the layers of graphite. When the material is heated, the intercalate decomposes, releasing gases that cause the graphite to expand and separate into a worm-like structure.

Q: Is expandable graphite environmentally safe?

A: Expandable graphite itself is inert and non-toxic. However, the acids used during the intercalation process must be handled with care and disposed of properly. Once expanded, it is often considered a safer alternative to traditional fire retardants.

Q: What are the differences between natural and synthetic expandable graphite?

A: Natural expandable graphite is derived from naturally occurring flake graphite, while synthetic graphite is produced from petroleum coke. Natural graphite generally has larger flake sizes and better expansion properties, but synthetic graphite can offer more consistent quality and purity.

Q: At what temperature does expandable graphite start to expand?

A: The expansion temperature can vary depending on the specific intercalant and manufacturing process, but it typically begins around 150°C to 250°C and can reach full expansion at temperatures above 300°C.

Q: Can expandable graphite be recycled?

A: While expandable graphite can be reused in some applications, once it has been expanded, it cannot revert to its original form. The expanded form may still have uses, such as in insulation or as a filler, but it will not have the same expansion properties as the unexpanded material.