Graphene is the world’s strongest material, but that’s not all it can do. The wonder material can also be used as a filter that removes salts from seawater so it’s safe to drink. While scientists have eyed graphene-oxide membranes for better filtration – and even showed graphene could filter out large salts – now 13 University of Manchester scientists developed graphene membranes that can sieve common, smaller salts out of water.
It takes small sieves to remove common salts from substances like seawater, and in the past when placed in water graphene-oxide membranes swelled, and weren’t able to catch those smaller salts. The University of Manchester scientists found a way to control the pore size of the graphene to sieve those common small salts out of water. Professor Rahul Nair, one of the scientists part of the research, said the realization of “membranes with uniform pore size down to atomic scale” is a significant step.
The discovery could open doors to efficient, less expensive desalination technology – which the university points out is crucial as climate change depletes water supply in modern cities. In just around eight years, 14 percent of the world’s population could face water scarcity, according to United Nations estimates, and not all countries can afford large, expensive desalination plants to provide relief to their citizens. The university says the graphene technology pursued by the scientists could revolutionize water filtration around the world, offering an affordable option for developing countries.
The researchers think their discovery could be scaled up for wider use. Nair said in a statement, “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.”
The journal Nature Nanotechnology published the research online yesterday.