An international team of scientists from eleven research institutions took a completely different approach to produce an aqueous solution with metallic properties for the first time and documented this phase transition in the BESSY II project. To this end, they experimented with alkali metals, which release valence electrons very easily.
The phase transition to metallic water can be seen with the naked eye! The silver sodium-potassium drop is covered with a golden sheen, which makes a huge impression.Dr. Robert Seidel of the Helmholtz-Zentrum Berlin for Materialien und Energie
Water can be turned into metal – no need for high pressure
At high enough pressure, almost any material can theoretically become a conductor. This is because if we compress the atoms tightly enough, the orbits of the outer (valence) electrons will begin to overlap, allowing them to move. In the case of water, the pressure is about 48 megabars – about 48 million times the atmospheric pressure at sea level.
Although it was possible to generate pressures in excess of this value under laboratory conditions, such experiments would not be suitable for investigating metallic water. That’s why a team of researchers led by organic chemist Pavel Jungvirt of the Czech Academy of Sciences in the Czech Republic turned to the alkali metals.
These substances release their outer electrons very easily, meaning they could induce electron-sharing properties in pure water without the need for high pressure. There’s just one problem: alkali metals are very reactive with liquid water, sometimes even causing an explosion.
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This problem is solved. What if instead of adding metal to water, we add water to metal? In a vacuum chamber, the team began by extruding a small blob of sodium-potassium alloy from the nozzle, which is liquid at room temperature, and very carefully added a thin layer of pure water using vapor deposition. Upon contact, electrons and metal cations flow into the water from the alloy. This not only gives the water a golden glow, but also makes the water electrically conductive. This was confirmed by reflection optical spectroscopy and synchrotron X-ray photoelectron spectroscopy.
These studies may enable a thorough study of the extremely high pressure conditions inside the large planets. It is believed that, for example, liquid metallic hydrogen swirls in the icy planets of the Solar System – Neptune and Uranus. Only on Jupiter is the pressure high enough to cause pure water to metallize. The prospect of being able to recreate the conditions inside the planetary colossus of our solar system is – quite literally – electrifying. Details can be read in the diary Nature.