Ever since graphene was discovered in 2010 many research programs have been conducted to prove that it could be used in various electronic applications and in composite materials.
Though graphene has no internal structure and displays high conductivity and strength, it cannot be produced or used in a large scale due to the fact that graphene sheets stack easily through the Van der Waals attraction process resulting in loss of surface area. This makes it difficult for further processes such as compressing, mixing, heating, solvent washing as it becomes rigid.
Previous studies have used carbon spacers to maintain the distance between the carbon sheets. However, this procedure altered the chemical composition of graphene. Scientists at the Northwestern University have discovered that graphene could be made to retain its surface area and purity by crumpling the carbon sheets. The uneven surface which results from crumpling graphene sheets prevented them from stacking irrespective of how they were processed. For this purpose the research team created water drops containing graphene sheets and suspended them freely after which they blew the droplets inside a furnace using a carrier gas. When the water evaporated the graphene sheets formed into sphere-like shapes.
Graphene formed in such a way exhibited the same electrical properties as flat graphene sheets and are more useful for creating various materials. Graphene produced in such a manner became stronger, when the crumpled graphene sheets were stacked even closer. Studies are also being conducted to use this graphene platform to conserve energy.
Source: http://www.northwestern.edu