What are Carbon Aerogels?
Carbon aerogels are a class of ultra-lightweight, highly porous materials that consist primarily of carbon. They are derived from organic gels, where the liquid component is replaced by gas, leaving a solid network. These materials have a unique combination of properties, such as low density, high surface area, and excellent thermal and electrical conductivity.
How are Carbon Aerogels Synthesized?
The synthesis of carbon aerogels typically involves a sol-gel process followed by supercritical drying and pyrolysis. Initially, organic precursors like resorcinol and formaldehyde are polymerized to form a hydrogel. This hydrogel undergoes supercritical drying to produce an aerogel, which is then subjected to pyrolysis in an inert atmosphere to convert it into a carbon aerogel.
Low Density: They are among the lightest materials known, with densities as low as 3 mg/cm³.
High Surface Area: Their surface area can exceed 1500 m²/g, making them ideal for applications requiring extensive surface interactions.
Electrical Conductivity: They exhibit good electrical conductivity, useful in applications like supercapacitors.
Thermal Insulation: Their low thermal conductivity makes them excellent thermal insulators.
Energy Storage: They are used in supercapacitors and batteries due to their high surface area and electrical conductivity.
Environmental Remediation: Their high porosity makes them effective in absorbing pollutants and contaminants.
Thermal Insulation: They are used in spacecraft and other high-tech applications for thermal management.
Catalysis: Their large surface area and porosity make them excellent supports for catalysts in various chemical reactions.
Cost: The production process is complex and expensive, limiting their widespread use.
Mechanical Strength: They are often fragile and brittle, requiring careful handling and potential reinforcement.
Scalability: Producing them on a large scale while maintaining quality is challenging.
