Graphene sieve turns seawater into drinking water

A lot of interest has been focused on graphene-oxide membranes as possible options for novel filtering methods. The long-awaited breakthrough of creating membranes that can filter common salts has finally been made.

Several studies show that there is a practical chance to supply millions of people who lack access to sufficient sources of clean water with potable water.

The journal Nature Nanotechnology released the latest research results from a team of scientists from The University of Manchester today. In the past, graphene-oxide membranes have demonstrated intriguing possibilities for water filtration and gas separation.

The National Graphene Institute's created graphene-oxide membranes have already shown promise in removing big salts, organic compounds, and even tiny nanoparticles. Nevertheless, they have not yet been able to be utilized for the sifting of common salts needed for desalination technologies, which need for even smaller sieves.

Prior studies conducted at The University of Manchester discovered that when graphene-oxide membranes are submerged in water, they swell somewhat and allow tiny salts to pass through with the water, but bigger ions or molecules are inhibited.

Now, the Manchester-based team has improved upon these graphene membranes and discovered a way to prevent the membrane from expanding in the presence of water. By carefully adjusting the membrane's pore size, salted water may be made safe to drink by removing common salts.

The affluent contemporary nations are also investing in desalination technology as the consequences of climate change continue to diminish modern cities' water resources. Major affluent communities in California are likewise turning more and more to alternate water solutions in the wake of the devastating storms.

A'shell' of water molecules always forms around the salt molecules when common salts are dissolved in water. This enables the graphene-oxide membranes' small capillaries to stop the salt from moving with the water. The membrane's ability to allow water molecules to flow through abnormally quickly makes it perfect for use in desalination processes.

"Realization 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," stated Professor Rahul Nair of The University of Manchester.

This regime's first experiment with precision is this one. We also show that it is feasible to scale up the disclosed method and create large-scale graphene-based membranes with the necessary sieve sizes."

The study's co-lead authors were Mr. Jijo Abraham and Dr. Vasu Siddeswara Kalangi. Mr. Abraham stated, "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."

According to UN estimates, 14% of the world's population would face water scarcity by 2025. This technique might completely change the way that water is filtered across the world, especially in those nations that cannot afford to build large-scale desalination plants.

Without sacrificing the amount of fresh water generated, it is envisaged that graphene-oxide membrane systems may be constructed on smaller sizes, making this technology available to nations without the financial means to support huge facilities.