Despite being just an atom thick, graphene is nearly impermeable and potentially capable of blocking everything from bullets to minuscule gas molecules. Companies are already pouncing on adapting this characteristic to applications like filtration and desalinization.
New research out of Rice University indicates that graphene’s impermeability also makes it a fit for cars that run on natural gas. Right now, natural gas is packed into heavy metal tanks that must be stored somewhere on a car. The researchers were able to combine plastic and graphene to create a plastic tank capable of holding natural gas. Lighter plastic tanks could make cars more efficient by lowering the amount of fuel they need.
To prevent gas from escaping, the researchers embedded graphene ribbons in plastic. This is a view of the embedded ribbons under an electron microscope. Photo courtesy of Tour Group/Rice University.
“The idea is to increase the toughness of the tank and make it impermeable to gas,” Rice chemist James Tour said in a release. “This becomes increasingly important as automakers think about powering cars with natural gas. Metal tanks that can handle natural gas under pressure are often much heavier than the automakers would like.”
Because it is not yet affordable to manufacture sheets of graphene in bulk, the researchers turned to graphene nanoribbons. Nanoribbons are made by unzipping carbon nanotubes, which are composed of rolled up pieces of graphene. Carbon nanotube manufacturing is much more advanced than graphene manufacturing, as is graphene nanoribbon manufacturing.
The nanoribbons were then embedded in plastic. While this combination is more permeable than a solid sheet of graphene, it is still 1,000 times harder for gas to escape than if it was faced with a plain plastic wall.
The researchers say their creation also can be applied to soda and beer bottles. Adding graphene to plastic bottles would extend the shelf life of soda before it goes flat. And, plastic bottles laced with graphene could keep beer fresh. Plastic bottles aren’t used for beer now because oxygen can enter them, causing beer to go bad.