*This is one of those developments that sound obscure and technical, but if you can clean water of impurities at low or zero cost, then water conditioning might be a bigger deal than air-conditioning.
http://web.mit.edu/newsoffice/2014/how-to-create-selective-holes-in-graphene-0225.html
(…)
"A big limitation in existing nanofiltration and reverse-osmosis desalination plants, which use filters to separate salt from seawater, is their low permeability: Water flows very slowly through them. The graphene filters, being much thinner, yet very strong, can sustain a much higher flow. "We've developed the first membrane that consists of a high density of subnanometer-scale pores in an atomically thin, single sheet of grapheme," O'Hern says.
"For efficient desalination, a membrane must demonstrate “a high rejection rate of salt, yet a high flow rate of water,” he adds. One way of doing that is decreasing the membrane’s thickness, but this quickly renders conventional polymer-based membranes too weak to sustain the water pressure, or too ineffective at rejecting salt, he explains.
"With graphene membranes, it becomes simply a matter of controlling the size of the pores, making them “larger than water molecules, but smaller than everything else,” O’Hern says — whether salt, impurities, or particular kinds of biochemical molecules.
"The permeability of such graphene filters, according to computer simulations, could be 50 times greater than that of conventional membranes…"
