 The theory had shown that graphene wasn't possible to exist in nature. It wasn't stable. Then many people didn't think to look for it as a true two-dimensional material. And Andre Geim and Kostya decided that this was not necessarily true, and so they went looking for it. And the way that they went looking for it was using, as you've probably heard of the scotch tape method, which involves sellotape and a piece of not pencil, but of high-purity graphite. How do we go from this layered material to getting a single layer? A layer that's only one atom thick, a layer of graphene, is actually frisely simple. You need to use a simple piece of sticky tape, and we use the tape to pull the layers of graphite apart. And every time we pull the tape apart, we break our graphite up, we're cleaving it, pulling apart the layers. So the pieces of graphite we had in here originally would have contained many thousands of layers. And if we do this enough times, we can hopefully end up with some layers that are only one or two atoms thick. One of the things that really helped us to understand that you really did have graphene was the types of very exciting new microscopes that are now available. And was the availability of these microscopes that really helped them understand that what they actually had was a single atomic layer. Once you've worked with graphene for a while, you get very used to looking at it, and it's very easy for me to say that that is monolayer graphene. Well, this here is probably two layers, and these bits here are really quite thick. My name is Rahul Arnayar. My area of research is graphene-based membrane. So graphene oxide is super permeable to water, which means there is no resistance or barrier for water molecule to evaporate through graphene oxide. So this is how we produce our graphene oxide membrane for our laboratory experiments. So you use this kind of porous support material to deposit graphene oxide sheet to make a free-standing membrane. So you use porous support there. Then you pour graphene oxide solution over here. So this is a graphene oxide solution in water. It has single graphene oxide dispersed in pure water. Then you use this water on top of this porous aluminum membrane. Then you start pumping using a vacuum pump. Then you remove all liquid water through this aluminum membrane and your graphene oxide sheet get deposited on top of this aluminum. And finally, after drying, you can peel it off this free-standing graphene oxide and you can study membrane property or you can also characterize this membrane using different technique. Graphene oxide was shown by Rahul in the physics department here to have high permeability to water but to be an effective barrier to all kinds of other things. One of the ideas is to use graphene as a type of nanomembrane or filter and that harnesses the fact that graphene is very impermeable. Even very light gases don't pass through and that means that if we were able to tailor the size of the pores within the graphene lattice, it might be possible to produce a very selective filter or perhaps use smaller graphene sheets and use the pathways in between the sheets in order to tailor the porosity or the permeability of the membrane. 40 years ago or so, desalination used to be based mainly on thermal methods whereby you would use high temperatures to separate clean water from the sea water and extract it that way. That was high energy, it was high cost and some plants in the Gulf still use that method, I believe but it's not currently what's used now. So now there's been a growing trend towards, over the last 40 years, a growing trend towards use of reverse osmosis and membrane technology in provision of desalinated water whereby you move the sea water across a semi permeable membrane and you have the desalinated water on the other side of the membrane. So this can be a world of difference to what happens on a small scale in the lab and what happens when you have football fields worth of membrane area on a real plant. So there are many challenges to actually getting a new membrane material accepted and used commercially on an industrial scale.