Water that never freezes24th April 2019
SWITZERLAND: Scientists have managed to reduce the temperature of water to within 10ºC of absolute zero without it turning into ice.
Led by Professors Ehud Landau and Raffaele Mezzenga, a group of physicists and chemists from the University of Zurich and ETH Zurich have now identified an unusual way to prevent water from forming ice crystals, so even at extreme sub-zero temperatures it retains the amorphous characteristics of a liquid.
In a first step, the researchers designed and synthesised a new class of lipids (fat molecules) to create a new form of “soft” biological matter known as a lipidic mesophase. In this material, the lipids spontaneously self-assemble and aggregate to form membranes, behaving in a similar way as natural fat molecules.
These membranes then adopt a uniform arrangement to form a network of connected channels that measure less than one nanometer in diameter. This structure leaves no room in the narrow channels for water to form ice crystals, so it remains disordered even at extreme sub-zero temperatures. The lipids don’t freeze either.
Using liquid helium, the researchers were able to cool a lipidic mesophase to a temperature as low as -263ºC with no ice crystals formed. At this temperature, the water is described as becoming “glassy”.
The research is said to be paving the way for future projects to determine how proteins might be preserved in their original form and interact with lipid membranes at very low temperatures. This new class of soft matter could also be employed in potential applications wherever water must be prevented from freezing.