Water is weird and yet so important. In fact, it is one of the most unusual molecules on Earth—it boils at a temperature it shouldn’t, it expands and floats when in a solid-state, and its surface tension is higher than it should be.
Now, U.S. National Science Foundation-funded research published in Nature has added one more strange property to water’s list of oddities. The implications of this new revelation could impact all water-related processes, from water purification to drug manufacturing.
University of Southern California researchers Stephen Cronin and Alexander Benderskii have shown that when water contacts an electrode surface, all the molecules do not respond in the same way. That can dramatically affect how well various substances dissolve in water.
Cronin designed a unique electrode built from monolayer graphene—just 0.355nm thick. Building graphene electrodes is a complex process. The electrode needed for the research is one that groups across the globe have tried to build but failed to do in the past.
Once the electrode is placed on a cell of water and begins running a current, Benderskii uses a special laser spectroscopy method. “Using our approach to observe water molecules, we were able to see how the molecules interacted with the field in a way no one had previously understood,” Benderskii said.
The top layer of the water molecules closest to the electrode aligns in a completely different way than the rest of the water molecules. The realization was unexpected and could open the way to more accurate simulations of how aqueous chemical reactions in various fields affect materials.
An area where the finding could have an immediate impact is in providing clean water. “Water in contact with graphene is being proposed as a new technology in desalinization,” Cronin said. “Our research could help scientists design better simulations that will ultimately bring desalinated water faster, cheaper, and cleaner.”
Source: National Science Foundation