Science News
from research organizations

Sneaking up on the glassy transition of water

Date:
September 27, 2011
Source:
American Institute of Physics
Summary:
Researchers claim to have settled a long-standing debate over the exact temperature at which water transforms into an exotic glass-like substance believed to be present in comets and other icy objects in the outer solar system, as well as in the coldest regions of the Earth's atmosphere.
Share:
         
Total shares:  
FULL STORY

Researchers claim to have settled a long-standing debate over the exact temperature at which water transforms into an exotic glass-like substance believed to be present in comets and other icy objects in the outer solar system, as well as in the coldest regions of Earth's atmosphere.

Rapid cooling of ordinary water or compression of ordinary ice: either of these can transform normal H2O into an exotic substance that resembles glass in its transparency, brittleness, hardness, and luster. Unlike everyday ice, which has a highly organized crystalline structure, this glass-like material's molecules are arranged in a random, disorganized way. Scientists have studied glassy water for decades, but the exact temperature at which water acquires glass-like properties has been the subject of heated debate for years, due to the difficulty of manipulating pure glassy water in laboratories.

Now, in a paper published in the AIP's Journal of Chemical Physics, physicists from the University of Pisa and the Consiglio Nazionale delle Ricerche at the Institute for Chemical-Physical Processes (CNR-IPCF) in Pisa, Italy, claim to have put an end to the controversy. Unlike previous attempts in which scientists tried to measure the transition temperature directly, the CNR team "snuck up" on the answer by inferring the temperature from a thorough study of the dynamics of water. They examined water's behavior in bulk and at the nano-scale, at high temperatures and low, combining their own experimental results with 15 decades' worth of research by colleagues.

They also measured the glass transition temperature and the molecular behavior of water that had been doped with other materials, and used this information to set lower and upper boundaries on the transition temperature for pure water. Taken together, their evidence points to a magic number of approximately 136 Kelvin (-137 Celsius). The authors say their work supports traditional views of this phenomenon and refutes recent claims that the transition is above 160 Kelvin (-113 Celsius). The research could find uses in technology associated with food science and the cryopreservation of biological materials, as well as in the study of water in comets and on the surface of planets.


Story Source:

The above story is based on materials provided by American Institute of Physics. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Capaccioli, K. L. Ngai. Resolving the controversy on the glass transition temperature of water? The Journal of Chemical Physics, 2011; 135 (10): 104504 DOI: 10.1063/1.3633242

Cite This Page:

American Institute of Physics. "Sneaking up on the glassy transition of water." ScienceDaily. ScienceDaily, 27 September 2011. <www.sciencedaily.com/releases/2011/09/110926104618.htm>.
American Institute of Physics. (2011, September 27). Sneaking up on the glassy transition of water. ScienceDaily. Retrieved April 26, 2015 from www.sciencedaily.com/releases/2011/09/110926104618.htm
American Institute of Physics. "Sneaking up on the glassy transition of water." ScienceDaily. www.sciencedaily.com/releases/2011/09/110926104618.htm (accessed April 26, 2015).

Share This Page:


Matter & Energy News
April 26, 2015

Latest Headlines
updated 12:56 pm ET