Special filters transform seawater into drinking water.

Graphene oxide membranes have the ability to remove salt from seawater, converting it into drinking water.

Graphene oxide membranes are capable of removing salt from seawater. Photo: University of Manchester.

Scientists at the University of Manchester, UK, have successfully created a graphene oxide membrane capable of removing salt from seawater to convert it into drinking water with high efficiency, according to the BBC. The research results were published in the journal Nature Nanotechnology on April 3rd.

Graphene oxide is produced by a simple oxidation process in the laboratory. We coat graphene oxide onto a substrate or porous material and use it as a film.Rapene oxide has great potential."It has both practical applications and lower material costs compared to conventional graphene," said Rahul Nair, the lead author of the study.

In typical graphene membranes, a layer of carbon atoms is arranged in a hexagonal lattice, forcing manufacturers to drill tiny holes in the membrane—smaller than a nanometer—to prevent salt molecules from passing through. This is a very difficult task. Furthermore, it is difficult to produce large quantities of single-layer graphene using existing methods such as chemical vapor deposition (CVD), and graphene production is also quite expensive.

Previously, graphene oxide membranes have been shown to effectively filter nanometer-sized particles, organic molecules, and large salts, but they have not yet been used to filter small salts. This is because graphene oxide membranes swell when submerged in water, allowing small salt molecules to flow through the pores in the membrane along with the water.

To overcome this problem, Nair and colleagues placed epoxy resin barriers on either side of the membrane to prevent its expansion. This allowed the scientists to adjust the properties of the filter membrane, allowing less salt to pass through or preventing smaller salt particles from passing through.

By 2025, the United Nations estimates that 14% of the world's population will face water scarcity due to climate change. Many countries around the world are investing in desalination technology, with current membrane filters made of polymers.

"This is the first time we've been able to control the spacing and pore size on the filter membrane to desalinate seawater. The next step is to compare it to existing materials on the market," Nair said.

According to VNE