Since Faraday’s discovery, the characteristics of such water – like layer have been the study topic of researchers all across the world that has entailed considerable controversy, at what temperature does the surface become like liquid? How does thickness of layer dependent on temperature? How does the layer’s thickness increases with temperature?
Studies till date have usually revealed a slightly thin layer that regularly grows in thickness up to 45 nm right below the hefty melting point at 0 Degree Celsius. It also showcases why it has been so challenging to study such layer of liquid – like water on ice – 45nm is about 1/1000th part of a human hair and is not discernible by eye.
Researchers from the Max Planck Institute for Polymer Research, in association with scientists from the Netherlands, Japan and USA, have succeeded to identify the properties of such quasi – liquid layer on the ice at molecular level utilizing advanced surface – specific computer simulations and spectroscopy. The group of researchers around Ellen Backus, head at MPIP, investigated how the sleek liquid layer is prepared on ice, how it expands with increasing temperature and it is differentiable from normal liquid water.
Such studies need well – defined ice crystal surfaces and hence much focus was placed into creating a 10cm big single crystal of ice that could be sliced in such a way that surface structure was accurately known. To identify whether the surface was liquid or solid, the group made use of the fact that molecules of water in liquid state have weaker interaction with each other in comparison to liquid molecules in ice. With such interfacial spectroscopy, linked with the regulated heating of the ice crystal, the scientists were able to quantify the change in the linking between water molecules directly at the interface between air and ice.
The studies reveal, combined with simulations that the first layer of molecules at the ice surface has already melted at temperatures as low as -38 Degree Celsius, the lowest temperature the scientists could experimentally identify. Increasing the temperature to – 16 Degree Celsius, the second layer becomes liquid. As compared to the common belief, the surface melting point of ice is not a regular process, but occurs in a discontinuous layer – by – layer form.
“A further vital question for us was whether one liquid varies between the properties of the quasi – liquid layer than those of normal water,” says Mischa Bonn, co – author of the study. “And indeed the quasi liquid layer at – 4 Degree Celsius revealed a varying spectroscopic response.”
Filed Under: News
Questions related to this article?
👉Ask and discuss on Electro-Tech-Online.com and EDAboard.com forums.
Tell Us What You Think!!
You must be logged in to post a comment.