Graphene formed by de Laval Nozzle:
Researchers at the Department of Mechanical and Industrial Engineering, University of Illinois at Chicago and the Department of Mechanical Engineering, Korea University have formed high quality graphene substrates by spray using a de Laval nozzle, commonly used in jet engines. A solution containing graphene flakes when blasted through a de Laval nozzle, a film of graphene forms of relative high quality. Researches are not certain why this happens, but the theory according to Alexander Yarin, co-leader of the research, the solution …” hits with enormous kinetic energy, and stretch in all directions. We’re tapping into graphene’s plasticity — it’s actually restructuring.”
Diagram of a de Laval nozzle, showing approximate flow velocity (v), together with the effect on temperature (T) and pressure (p) – Wikipedia
Other Methods of Graphene Formation:
Graphene is commonly made using CVD, drawback of CVD of course is it is restricted to a batch method and the sheets of graphene are limited to the size of the chamber. Also ultrasonic spray nozzles are also be used in a variety of applications both large and small substrates. Ultrasonic Spray Nozzles are non-clogging with very little to no overspray. They are also capable of spraying a very thin nanolayer of material with high uniformity.