The development of scientists from the University of Manchester is able to provide millions of people with access to clean fresh water. The technology based on the purification of seawater from solvates using a graphene oxide microfilter is much cheaper and less expensive than all existing ones. In addition, the very production of the oxidized form of graphene is much easier and cheaper than the production of graphene itself. Graphene oxides can be obtained in huge quantities.
According to Dr. Rahul Nair, scientists have learned how to obtain a microfilter from oxidized graphene by simply pouring a solution onto a substrate or porous material. The main thing is to make holes in graphene oxide membranes no more than one nanometer.
However, the team still had to find a way to use graphene oxide membranes to filter out salts. In previous studies, scientists found that membranes swell when immersed in water, their pores expand, allowing salts to pass through them freely. To solve this problem, Nair and his team covered both sides of the membranes with epoxy.
The pores of the epoxy coated membranes are too small for the salt molecules to pass through. However, they allow pure water molecules to pass freely, since their pore sizes of one nanometer are very close to those of water molecules.
Someday these graphene filters will be able to change life around the world. But before that happens, scientists must make sure that graphene oxide can withstand prolonged contact with seawater. The ultimate goal, Nair said, is to create a filtration device that will produce drinking water from seawater or waste water with minimal energy consumption.