Mechanochemistry:
Mechanochemistry refers to the coupling of chemical reactions with mechanical forces. [“Mechanochemistry: Fundamental Principles and Applications,” Wiley Advanced]
Noted in “How an ancient alchemy technique is transforming modern chemistry,” Hayley Bennett, NewScientist (24 May 2025, paywall):
Chemistry creates many of the wonders of modern life, from the medicines that heal us to the screens with which we communicate. When researchers want to make these things from scratch, they often start by assuming they must dissolve their materials. But mechanochemistry, the burgeoning field [Tomislav Friščić of the University of Birmingham, UK] is fascinated by, shows this isn’t always necessary. “Mechanochemistry gives you the intellectual freedom to think: ‘Let me just try this reaction by grinding it’,” says Friščić. “And, in many cases, it works.”
Bonus!
As well as creating new chemicals, mechanochemistry can be destructive – in a good way. At Utrecht University in the Netherlands, Ina Vollmer’s lab has been meticulous in trying to work out what happens when plastic waste is broken down in a ball mill. Vollmer came to mechanochemistry looking for a greener way to take spent plastics like polyethylene and polypropylene and turn them back into their chemical building blocks. “We were really thinking about it for circularity and recycling, to make these polymers again,” she says.
Such chemical recycling is already possible, but it requires temperatures of around 300°C (570°F), meaning plastics are usually melted and reshaped instead. However, Vollmer’s team recently succeeded at doing it at room temperature using an ingenious milling system in which the catalysts driving the reactions are stuck to the balls themselves. They can throw in pellets of plastic – from old garden chairs and toys, for example – and get out hydrocarbon gases like propene. According to Vollmer, the team is now building a bigger ball mill and founding a start-up to commercialise the process. It is a stunning example of what mechanochemistry can do, says Friščić.
