CSIRO scientists have created a filtration technique using a graphene-based film, called “Graphair”, with microscopic nano-channels that lets water pass through but stops pollutants.
Graphene is normally made using an energy-intensive process of chemical vapour deposition onto metal substrates. Graphair, on the other hand, is made from renewable soybean oil which makes it comparatively cheap, fast and environmentally-friendly to make.
Water purification usually involves a complex process of several steps, Graphair filtration can replace this complex process with a single step.
One of the main problems with regular filters is that unwanted, filtered-out material tends to build up on the membrane, eventually slowing down the rate that water can pass through. In their tests, the researchers found that, after 72 hours, standard filters were only half as effective as they had been initially whereas graphair filters did not become any less effective.
The researchers believe that this breakthrough could have a significant benefit for the more than 2 billion people who don’t have clean, safe drinking water.
The researchers are hoping to commence field trials in a developing country next year and are looking for industry partners to help scale up the technology. They are also working on other applications for Graphair, such as for seawater and industrial effluents.