Water may transform into a superacidic fluid under extreme heat and pressure. These conditions are found only in Earth鈥檚 interior, within icy planets like Uranus and Neptune 鈥� and possibly in controlled laboratory experiments.
鈥淯nder immense pressures and temperatures, water exhibits a remarkable property 鈥� it becomes an exceptionally potent acid, also known as a 鈥榮uperacid鈥�, which can be billions or even trillions of times stronger than sulphuric acid,鈥� says at Sorbonne University in France.
This superacid transformation appears to occur at temperatures between 1727掳C and 2727掳C (3140-4940掳F) and at intense pressures of 22 to 69 gigapascals. For comparison, 2727掳C is the temperature of sunspots on the sun鈥檚 surface, and 50 gigapascals would correspond to 鈥渉aving 100 elephants standing on the tip of your finger鈥�, says Siro Brigiano.
Advertisement
He and his colleagues made this discovery using computer simulations that model the motions of atoms and chemical reactions. They also trained a machine learning model on the simulation results and used it to perform additional calculations in a more computationally efficient way.
The simulations also showed how, under the same extreme conditions, the superacidic water can turn hydrocarbon molecules such as methane into diamond-like structures such as methanium, a chemical transformation previously studied in other superacid solutions. This aspect of water鈥檚 chemistry may explain earlier research that suggests icy giant planets, including Uranus and Neptune, experience diamond rain, says coauthor at the French National Centre for Scientific Research.
Superacidic water could also find practical applications like inspiring future lab processes for creating diamonds or even replacing traditional superacids in industrial processes such as petroleum refining, says France-Lanord.
The description of water鈥檚 superacid transformation is 鈥渋ntriguing鈥�, but the real-world applications may be limited by the need for extreme conditions, says at Emory University in Atlanta, Georgia. And superacidic water鈥檚 relationship with diamond rain also remains speculative, he says.
A next big step would be to collect direct experimental evidence for water鈥檚 superacid chemistry, says France-Lanord. He and his colleagues are exploring ways to do that in the lab, at lower pressures and temperatures 鈥� which could also make practical applications more feasible.
arXiv
