Two researchers at the University of Southern California (USC) have shown that when a graphene electrode is placed into water the molecules of water closest to the electrode “align in a completely different way than the rest of the water molecules,” a result that was not anticipated. The findings may have implications in many fields, especially in methods proposed for desalinization of water.
What does it mean?
Water has many strange properties, according to Alok Jha, author of The Water Book. Unlike most other liquids, water expands when it freezes; thus, ice floats in water, insulating life under the ice. Water in rocks expands in the cold and cracks the rocks open, an important fact in the creation of soil. Water, even though made from two gases, is a liquid. It has a surprisingly large surface tension, enabling insects to walk on it. The attraction between water molecules leads to capillary action, important to all life. Almost anything dissolves in water. I could go on and on since Rachel Brazil claims that water “has at least 66 properties that differ from most liquids – high surface tension, high heat capacity, high melting and boiling points and low compressibility.”
The electrode the researchers used is made from graphene, a very interesting form of carbon in which the carbon atoms are arranged in a single layer honeycomb lattice. It has promise to improve battery performance, hence its use as an electrode in this experiment.
The result they observed occurs at the surface of the electrode, where the water and electrode meet. Many interesting chemical and physical effects occur at surfaces. One of the researchers at USC concentrates on the molecular structure and physics of surfaces,” as explained at this web page about the Benderskii Research Group.
What does it mean for you?
I draw two lessons from these facts about water and from the newly reported research. First, science has increased our understanding of the world amazingly, but some simple parts of our world still defy our understanding; at least sometimes engineers can use the natural world in ways that science does not actually understand well. The fact that discoveries continue to be made about water – water! – amazes me.
Second, discoveries continue to be made that will improve our ability to generate, distribute, and use electrical energy. While not mentioned in the article, this result has implications for the development of batteries. I believe that we must move much more quickly than we are doing now to reduce the emissions of greenhouse gases to head off the climate changes that are occurring, but I also believe that surprises await us in science, engineering, and technology that will help us along this path. Stay tuned for more news.
Where can you learn more?
As you might expect, the US Geological Services (USGS) has a great page about the properties of water. This BBC animation, narrated by author Alok Jha, explores some of the strange properties of water. Some of those properties are listed here.