Diamonds are pretty darn tough. How tough? Tough enough that squeezing a couple of them together in a molecular diamond anvil — a technique that’s capable of achieving 100 times the pressure experienced at the bottom of the Mariana Trench — can be used to create custom molecules through the triggering of unique chemical reactions.
“Chemical reactions are at the core of modern-day society, from making new therapeutic drugs to fertilizer for food,” Nicholas Melosh, an associate professor of Materials Science and Engineering at Stanford University, told Digital Trends. “Most of these reactions are carried out using chemicals or heat to drive the reaction. However, it’s long been a goal to realize alternative ways to perform chemical reactions, such as with mechanical force.”
In their demonstration, the Stanford researchers demonstrated a first step toward this goal by showing that rigid molecules can be used as “molecular anvils” to crush a softer molecular component, thereby causing a reaction.
“This is a new idea,” Melosh continued. “It came about after we had synthesized one of the precursor molecules for a different project. That molecule was actually one that didn’t react with mechanical force, but it got us thinking about whether such a thing could be possible by altering the molecule shape we used. After compressing a few different candidates in collaboration with a fantastic group that does high pressure at Stanford, Wendy Mao, we found what we were looking for: An irreversible electrochemical reaction purely driven by mechanical force.”
As noted, at this stage it’s still more of a fancy tech demo than anything. But the work could have real-world applications. Melosh said that he hoped the model can be applied to other chemical systems as well — improving the selectivity and efficiency of the reactions. “We would love to develop mechanical approaches for difficult reactions, like CO2 reduction, that, while quite hard, could have considerable impact,” he said. One day, it may be used to create custom molecules on-demand for use in pharmaceuticals.
A paper describing the work, “Sterically controlled mechanochemistry under hydrostatic pressure,” was recently published in the journal Nature.