Revealing the secret of 'hot ice'

 作者:赏俱     |      日期:2019-03-15 06:04:01
By Zeeya Merali FOR most people, making ice is a simple matter of popping a tray of water in the freezer. But not for chemist Eun-Mi Choi and his colleagues at Seoul National University in South Korea. Sub-zero temperatures and novelty moulds are the last things on their minds. They prefer to make their ice by zapping water with electric fields – and they do it at room temperature. “Ice existing at room temperature – ‘hot ice’ – makes the mind boggle,” says Denys Wheatley, a cell biologist who studies the effects of water on living systems at the University of Aberdeen, UK. “It just shouldn’t happen.” Choi’s experiments earlier this year have ended a 10-year quest to find out whether hot ice can be made. But they have unwittingly sparked another mystery. According to Choi’s results, the electric field needed to transform lukewarm water into ice is surprisingly small. So small in fact that fields of similar magnitude are found in all sorts of nooks and crannies in nature, from cracks in rocks and clay particles to the crevices of proteins in our bodies. And the search is now on to find out whether hot ice really is lurking in nature. The story of room-temperature ice began in 1995 with an accidental discovery by materials scientist Jacob Klein at the Weizmann Institute of Science in Rehovot,