Scientists at the University of Technology, Sydney (Australia) are developing a composite material based on graphite that is a thin as paper and ten times stronger than steel.
|Graphene paper sample. Picture by Lisa Aloisio, UTS. Click to enlarge.|
In work recently published in the Journal of Applied Physics, a UTS research team supervised by Professor Guoxiu Wang has developed reproducible test results and nanostructural samples of graphene paper, a material with potential applications in the automotive, aviation, electrical and optical industries.
Graphene paper (GP) is a material that can be processed, reshaped and reformed from its original raw material state—graphite. Researchers at UTS have successfully milled the raw graphite by purifying and filtering it with chemicals to reshape and reform it into nano-structured configurations which are then processed into sheets as thin as paper.
These graphene nanosheet stacks consist of monolayer hexagonal carbon lattices and are placed in perfectly arranged laminar structures which give them exceptional thermal, electrical and mechanical properties.
Using a synthesized method and heat treatment, the UTS research team has produced material with extraordinary bending, rigidity and hardness mechanical properties. Compared to steel, the prepared GP is six times lighter, five to six times lower density, two times harder with 10 times higher tensile strength and 13 times higher bending rigidity.
Graphene paper (GP) has been prepared by flow-directed assembly of graphene nanosheets. The mechanical properties of as-prepared GPs were investigated by tensile, indentation, and bending tests. Heat treated GPs demonstrate superior hardness, ten times that of synthetic graphite, and two times that of carbon steel; besides, their yielding strength is significantly higher than that of carbon steel. GPs show extremely high modulus of elasticity during bending test; in the range of a few terapascal. The high strength and stiffness of GP is ascribed to the interlocking-tile microstructure of individual graphene nanosheets in the paper. These outstanding mechanical properties of GPs could lead to a wide range of engineering applications.—Ranjbartoreh et al.
Ali R. Ranjbartoreh, Bei Wang, Xiaoping Shen, and Guoxiu Wang (2011) Advanced mechanical properties of graphene paper. J. Appl. Phys. 109, 014306 doi: 10.1063/1.3528213