Water scarcity is one of the biggest issues the world faces today, with the UN predicting that 14% of the world population will be affected from this by 2025. A team of scientists at the University of Manchester have made a breakthrough in their research of Graphene Oxide, identifying its promising properties which could be the key to improving the accessibility to clean water for millions around of the world.
The breakthrough study has identified the strong properties of Graphene Oxide Membranes in the separation of gases, and water filtration. Previous research at the National Graphene Institute found Graphene Oxide Membranes to be effective in the filtration of small nanoparticles, organic molecules and large salts. The finding of this recent study is monumental, for the first time it has identified the potential use of Graphene Oxide Membranes in de-salination technologies, which can be used for sieving out common salts. Desalination technologies are currently attracting a lot of investment as worlds city’s water supply dwindles due to climate change.
Previous research identified that Graphene Oxide membranes would swell when submerged into water. The swelling managed to contain large ions and molecules but failed to prevent the movement of smaller molecules through this membrane. The team from Manchester has now managed to find ways to control the pore size and prevent swelling of the membrane. This allows the sieving of common salts, giving Graphene Oxide membranes the potential of making salty water safe to drink.
How does this work?
When dissolved in water, common salts organize themselves so their individual particles are surrounded by water molecules in a ‘shell’ like arrangement. The small Graphene Oxide membranes thus prevent the movement of salt with the water. Water molecules are still able to pass through the membrane at a fast pace, making it perfect to use in desalination technologies.
Professor Rahul Nair, at The University of Manchester said: “Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology. This is the first clear-cut experiment in this regime. We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes.”
Mr. Jijo Abraham and Dr. Vasu Siddeswara Kalangi were the joint-lead authors on the research paper: “The developed membranes are not only useful for desalination, but the atomic scale tunability of the pore size also opens new opportunity to fabricate membranes with on-demand filtration capable of filtering out ions according to their sizes.” said Mr. Abraham.
The aim is to now build small scale Graphene Oxide membrane systems to make this technology accessible, for countries who do not have the financial infrastructure.