MSGID: 1:317/3 63dc8de3   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    New ice is like a snapshot of liquid water    
      
     Date:   
         February 2, 2023   
     Source:   
         University of Cambridge   
     Summary:   
         Scientists have discovered a new form of ice that more closely   
         resembles liquid water than any other and may hold the key to   
         understanding this most famous of liquids.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
   FULL STORY   
   ==========================================================================   
   A collaboration between scientists at Cambridge and UCL has led to the   
   discovery of a new form of ice that more closely resembles liquid water   
   than any other and may hold the key to understanding this most famous   
   of liquids.   
      
      
   ==========================================================================   
   The new form of ice is amorphous. Unlike ordinary crystalline ice where   
   the molecules arrange themselves in a regular pattern, in amorphous ice   
   the molecules are in a disorganised form that resembles a liquid.   
      
   In this paper, published in Science, the team created a new form of   
   amorphous ice in experiment and achieved an atomic-scale model of it in   
   computer simulation. The experiments used a technique called ball-milling,   
   which grinds crystalline ice into small particles using metal balls in a   
   steel jar. Ball- milling is regularly used to make amorphous materials,   
   but it had never been applied to ice.   
      
   The team found that ball-milling created a novel amorphous form of ice,   
   which unlike all other known ices, had a density similar to that of   
   liquid water and whose state resembled water in solid form. They named   
   the new ice medium- density amorphous ice (MDA).   
      
   To understand the process at the molecular scale the team employed   
   computational simulation. By mimicking the ball-milling procedure via   
   repeated random shearing of crystalline ice, the team successfully   
   created a computational model of MDA.   
      
   "Our discovery of MDA raises many questions on the very nature of   
   liquid water and so understanding MDA's precise atomic structure is very   
   important" comments co-author Dr. Michael Davies, who carried out the   
   computational modelling. "We found remarkable similarities between MDA   
   and liquid water."  A happy medium Amorphous ices have been suggested   
   to be models for liquid water. Until now, there have been two main types   
   of amorphous ice: high-density and low-density amorphous ice.   
      
   As the names suggest, there is a large density gap between them. This   
   density gap, combined with the fact that the density of liquid water lies   
   in the middle, has been a cornerstone of our understanding of liquid   
   water. It has led in part to the suggestion that water consists of two   
   liquids: one high- and one low-density liquid.   
      
   Senior author Professor Christoph Salzmann said: "The accepted wisdom has   
   been that no ice exists within that density gap. Our study shows that the   
   density of MDA is precisely within this density gap and this finding may   
   have far-reaching consequences for our understanding of liquid water and   
   its many anomalies."  A high-energy geophysical material The discovery   
   of MDA gives rise to the question: where might it exist in nature? Shear   
   forces were discovered to be key to creating MDA in this study.   
      
   The team suggests ordinary ice could undergo similar shear forces in the   
   ice moons due to the tidal forces exerted by gas giants such as Jupiter.   
      
   Moreover, MDA displays one remarkable property that is not found   
   in other forms of ice. Using calorimetry, they found that when MDA   
   recrystallises to ordinary ice it releases an extraordinary amount of   
   heat. The heat released from the recrystallization of MDA could play a   
   role in activating tectonic motions. More broadly, this discovery shows   
   water can be a high-energy geophysical material.   
      
   Prof. Angelos Michaelides, lead author from Cambridge, said: "Amorphous   
   ice in general is said to be the most abundant form of water in the   
   universe. The race is now on to understand how much of it is MDA and   
   how geophysically active MDA is."   
       * RELATED_TOPICS   
             o Matter_&_Energy   
                   # Nature_of_Water # Spintronics # Graphene #   
                   Nuclear_Energy # Materials_Science # Sports_Science #   
                   Nanotechnology # Physics   
       * RELATED_TERMS   
             o Android o Ice_shelf o Ice_core o Liquid_nitrogen_economy o   
             Evaporation o Fluid_dynamics o Ice_age o Supercooling   
      
   ==========================================================================   
   Story Source: Materials provided by University_of_Cambridge. The original   
   text of this story is licensed under a Creative_Commons_License. Note:   
   Content may be edited for style and length.   
      
      
   ==========================================================================   
   Journal Reference:   
      1. Alexander Rosu-Finsen, Michael B. Davies, Alfred Amon, Han Wu,   
      Andrea   
         Sella, Angelos Michaelides, Christoph G. Salzmann. Medium-density   
         amorphous ice. Science, 2023; 379 (6631): 474 DOI: 10.1126/   
         science.abq2105   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/02/230202153559.htm   
      
   --- up 48 weeks, 3 days, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 226/30 227/114 229/110   
   SEEN-BY: 229/111 112 113 114 307 317 400 426 428 470 664 700 292/854   
   SEEN-BY: 298/25 305/3 317/3 320/219 396/45   
   PATH: 317/3 229/426