Creating steam in seconds with nanoparticles

Washington Post : Researchers report that they obtained vapor by focusing sunlight on broadly absorbing metal or carbon nanoparticles dispersed in a liquid. And they did it without heating the fluid volume. So says a front-page blurb in the Washington Post that points readers to a news article about a scientific paper in the journal ACS Nano. The Rice University research, the Post says, “suggests myriad applications in places that lack electricity or burnable fuels. A sun-powered boiler could desalinate sea water, distill alcohol, sterilize medical equipment and perform other useful tasks.” Naomi Halas, an engineer and physicist speaking for the researchers, reportedly “said the nanoparticles are not expensive to make and, because they act essentially as catalysts, are not used up.” In bubbles, the nanoparticles release steam into air, then sink again; they resume the process when they encounter the focused light. The work reaffirms that nanoscale devices “behave in ways different from bigger objects.” The Bill and Melinda Gates Foundation, with its interest in developing countries, provided some of the funding.