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Precise and Scalable Fabrication of Graphene Foams
Graphene foams are three-dimensional (3D) porous materials that encompasses the characteristics of graphene including high thermal conductivity, large surface area, enhanced electrical conductivity and high mechanical strength. Traditional bulk graphene fabrication methods (dip-coating, self-assembly or vacuum filtration) often face precision control difficulty and current methods of producing graphene foams are subjected to size restriction and scale-up issues, resulting in limited surface area, electrical conductivity, and mechanical flexibility.
This technology aims to resolve the issues faced during scale-up by providing a novel method for fabricating graphene foam via a two-step process. A ceramic template is first produced through additive manufacturing methods to create the desired structural properties of the foam. Graphene is next deposited onto the ceramic scaffold using chemical vapour deposition before etching occurs to leave behind a highly porous lattice of graphene foam with very large surface area.
Technology Features, Specifications and Advantages
The technology comprises of a two-step process to fabricate precise geometrically designed graphene foams.
- An additive manufacturing technique (stereolitography or digital light processing) is used in the initial step to produce a ceramic template from a photopolymerizable slurry. Some ceramic materials which can be used include (but not limited to): silicon dioxide (silica or SiO2), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), or a combination thereof.
- Graphene is deposited onto the ceramic template via chemical vapour deposition, removing the ceramic template via wet chemical etching and free-drying, such that the graphene foam retains the 3D configuration.
Some features of the graphene foams produced using this novel method include :
- Excellent porosity (99.2%)
- Electrical conductivity (2.39 S cm-1)
- Density (18 mg/cm3)
- High specific surface area (994.2 m2/g)
- Good mechanical properties (Young’s Modulus 239.7 kPa)
- Excellent performance on sea water desalination or separation process (e.g., oil/water separation)
- Tunable surface properties
- Heat absorbing applications
- Oil/water separation
- Energy storage
- Wearable electronics
- Precise control of free-standing graphene monolith
- Scalable production of free-standing graphene monolith
- Large surface area, excellent conductivity, and mechanical flexibility