The common coating known as Teflon can keep food from sticking to cookware, but it’s notoriously difficult to break down safely. Now, researchers in the United Kingdom have discovered a simple and cost-effective solution to the problem. The results aren’t simply eco-friendly—they can also be upcycled into helpful toothpaste and drinking water additives. According to their study published on October 22 in the journal Journal of the American Chemical Society, all you need is some sodium metal and heavy shaking.
It’s been over 85 years since DuPont introduced Teflon to the world. Released in 1938 and technically known as Polytetrafluoroethylene (PTFE), the chemically inert, synthetic polymer is most famous for providing impressively nonstick coatings on cookware and other surfaces. It also is widely utilized as a container lubricant for corrosive materials and even medical equipment like catheters.
Teflon is also as renowned as it is infamous. Part of the larger family of poly- and perfluoroalkyl substances (PFAs), these synthetics are now synonymous with numerous environmental and public health issues. When burned, they also release toxic “forever chemicals” that linger in the environment for thousands of years. Researchers have experimented with ways to tackle Teflon for years, including a strategy combining chemical additives and LED light treatments.
Chemists collaborating between the UK’s University of Birmingham and Newcastle University may offer an even easier solution. The key to their approach is mechanochemistry. Gaining traction among environmental advocates, mechanochemistry induces chemical reactions through basic mechanical energy instead of energy-intensive heat sources.Â
“Our approach is simple, fast, and uses inexpensive materials,” study co-author Erli Lu said in a statement.
The first step for Lu and colleagues is to place sodium metal fragments and Teflon waste into a sealed steel container called a ball mill. Teflon’s nonstick, nonreactive characteristics hinge on its immensely strong carbon-fluorine bonds, but the ball mill can break these bonds apart by grinding them with the sodium metal. This breakage then causes the two ingredients to chemically react at room temperature. The final result? A combination of harmless carbon and sodium fluoride—a stable, inorganic salt frequently used for toothpaste and drinking water fluoridation.
“We used advanced solid-state Nuclear Magnetic Resonance spectroscopy…to look inside the reaction mixture at the atomic level. This allowed us to prove that the process produces clean sodium fluoride without any by-products,” explained study co-author Dominik Kubicki. “It’s a perfect example of how state-of-the-art materials characterisation can accelerate progress toward sustainability.”
The process makes such clean sodium fluoride that it can immediately be used without any additional purification steps. Aside from toothpaste and water, the compound can be used to create other fluorine-containing molecules for pharmaceuticals and medical diagnostic treatments. The team believes their novel approach may soon provide a roadmap for a fluorine circular economy, where valuable compounds are harvested from waste, instead of simply discarding or burning the materials.
“We hope it will inspire further work on reusing other kinds of fluorinated waste and help make the production of vital fluorine-containing compounds more sustainable,” said Lu.
