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MIT Scientists Develop Porous, Lightweight, 3-D forms of Graphene with Amazing Strength
Material scientists at Massachusetts Institute of Technology (MIT) have developed a lightweight, three dimensional and porous material by fusing graphene flakes. The 3D graphene based material features an amazing strength and its lightweight. Under heat and pressure during a lab experiment, MIT scientists managed to fuse graphene flakes into a strong material with structural form similar to coral. The research has been published in the journal Science Advances. Graphene has been regarded as the toughest material with amazing characteristics and has the potential to bring major changes in electronics industry. Only roadblock research teams face is commercially viable production of graphene.
Currently, graphene is available in two-dimensional form and in that form as well, it presents exceptional strength to weight ratio. MIT researchers added that the same technique can be used to convert other 2D materials to 3D. Graphene presents extremely (usually one atom thin) thin sheet of carbon atoms arranged in two dimensions. However, being extremely thin, these sheets can’t be used effectively to create three dimensional objects. The project undertaken by MIT scientists could change that.
The material created by MIT team is porous and is just 5 percent as dense as steel. The material showcases nearly 10 times higher strength compared to steel. This material can be used in many industries including electronics, aviation, automobiles and modern warfare.
The unique geometrical configuration of the newly created material from fused graphene flakes is what makes the material strong and lightweight. MIT researchers believe that with similar technique, other materials can be formed and they would also showcase amazing strength when they would be with similar geometrical configuration.
Markus Buehler, the head of MIT's Department of Civil and Environmental Engineering said, "You could either use the real graphene material or use the geometry we discovered with other materials, like polymers or metals. You can replace the material itself with anything. The geometry is the dominant factor. It's something that has the potential to transfer to many things."
Details of the technology developed under the current project have been provided in the research paper by Markus Buehler, the head of MIT's Department of Civil and Environmental Engineering (CEE) and the McAfee Professor of Engineering; Zhao Qin, a CEE research scientist; Gang Seob Jung, a graduate student; and Min Jeong Kang MEng '16, a recent graduate.
Buehler says that what happens to their 3-D graphene material, which is composed of curved surfaces under deformation, resembles what would happen with sheets of paper. Paper has little strength along its length and width, and can be easily crumpled up. But when made into certain shapes, for example rolled into a tube, suddenly the strength along the length of the tube is much greater and can support substantial weight. Similarly, the geometric arrangement of the graphene flakes after treatment naturally forms a very strong configuration.
The new configurations have been made in the lab using a high-resolution, multimaterial 3-D printer. They were mechanically tested for their tensile and compressive properties, and their mechanical response under loading was simulated using the team's theoretical models. The results from the experiments and simulations matched accurately.
For actual synthesis, the researchers say, one possibility is to use the polymer or metal particles as templates, coat them with graphene by chemical vapor deposit before heat and pressure treatments, and then chemically or physically remove the polymer or metal phases to leave 3-D graphene in the gyroid form. For this, the computational model given in the current study provides a guideline to evaluate the mechanical quality of the synthesis output.
The same geometry could even be applied to large-scale structural materials, they suggest. For example, concrete for a structure such a bridge might be made with this porous geometry, providing comparable strength with a fraction of the weight. This approach would have the additional benefit of providing good insulation because of the large amount of enclosed airspace within it.