Could superstar graphene solve the world’s water crisis?

11 Mar 2016

A lot of research into how graphene can be used as a water filter has emerged recently, meaning the wonder material is now firmly in position to cure most of humanity’s ailments.

A new “revolutionary” use of graphene to filter water could solve contaminated water issues throughout the world, according to a team of researchers from the US and Australia.

Using graphene oxide, the new filter allows water and other liquids to be filtered nine times faster than the current leading commercial filter. The key to making this filter was developing a viscous form of graphene oxide that could be spread very thinly with a blade.

Future Human

“This technique creates a uniform arrangement in the graphene, and that evenness gives our filter special properties,” Mainak Majumder, who led the research, said.

Abozar Akbari, who worked on the paper that is in Nature, said scientists had known for years that the wonder material could impress as a filter, but in the past the layers had been difficult and expensive to produce.

“It’s been a race to see who could develop this technology first, because until now graphene-based filters could only be used on a small scale in the lab,” Mr Akbari said.

Two-horse race

The race, it seems, was quite close as, a couple of weeks ago, Baoxia Mi caught our attention, a Berkeley professor whose graphene research seemed remarkably similar.

Having spent years looking at how to develop a new membrane that could outperform today’s water filtration technology and consume less energy in the process, graphene oxide (again) was the method of choice.

Made from a thin layer of carbon, the material is very light, very strong, very cheap and quite the conductor. Mi’s theory was that membranes made from graphene oxide can filter wastewater far better than current methods. Basically, it could outdo previous methods of using graphitic oxidem, which is too thick to be effective.

Mi’s findings? Well, a water filter comprised of membranes made up of layers of graphene 100,000 times thinner than a strand of human hair is quite effective.

The membranes Mi developed are much like a maze for water molecules. The water enters the maze and passes through a series of layers separated by spaces specifically designed to remove different types of contaminants.

“We made it from graphite, which is a material that we use in pencils, for example, so it’s cheap and relatively abundant. So we can use that and the process that we use to make from the graphite to the graphene oxide is actually quite scalable,” said Mi.

Mi was granted a patent on the membranes in 2015, with Majumder’s paper submitted the same year. Graphene, so wonderful that everyone wants a slice.

Main image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic