Water purification and desalination is one of the great challenges of mankind, with 1.1 billion people living without proper drinking water. In particular, portable water purifiers and filters are always in demand, and new technologies are being sought to lower the cost and energy footprint. Nanotechnology holds great potential for getting rid of bacteria and other harmful contaminants, and now graphene water filters are showing great potential.
Graphene sheets perforated by small holes have first been explored by researchers at MIT as potential candidates for water filtration. Holes with a diameter of 1 nanometer (a billionth of a meter) are big enough to let water molecules sift through, however small enough to stop any undesired chemicals. The news of MIT's discovery was so big that the Smithsonian magazine, the publication of the famous Smithsonian Institution, named it one of the top 5 surprising scientific milestones of 2012, along with the Higgs Boson, the discovery of Earth-like planets, and NASA’s Curiosity mission to Mars.
Whereas only one year ago nanometer-sized holes in graphene sheets sounded like a pipe dream, recent months brought news of actual graphene nanopore devices, with various uses such as DNA detectors or traps to study small numbers of silicon atoms. With graphene sheet nanopores a reality, a graphene water filter comes within reach.
Top-notch scientific researchers are not the only ones toying with the idea of solving the world's problems with graphene. Lockheed Martin, the famous weapon manufacturer, recently announced that it has obtained a patent for graphene nanopore-based water filters. The technology, called Perforene, is similar to that studied at MIT. A prototype is expected by the end of the year.
As with a few other high-tech applications of graphene, the technology for mass production has not yet been reached. However, with the likes of Lockheed Martin investing in the graphene nanomanufacturing, solutions are expected in the near future. The current results are very promising - graphene, due to its small weight and size, could significantly reduce the costs and energy footprint of portable water filters and desalinators.