Trang Almost Did Not Perform Simple Experiment Because “People Would Have Known This Already”

(p. D3) A team of scientists has found a cheap, effective way to destroy so-called forever chemicals, a group of compounds that pose a global threat to human health.

The chemicals — known as PFAS, or per- and polyfluoroalkyl substances — are found in a spectrum of products and contaminate water and soil around the world. Left on their own, they are remarkably durable, remaining dangerous for generations.

Scientists have been searching for ways to destroy them for years. In a study, published Thursday [Aug. 18, 2022] in the journal Science, a team of researchers rendered PFAS molecules harmless by mixing them with two inexpensive compounds at a low boil. In a matter of hours, the PFAS molecules fell apart.

. . .

At the end of a PFAS molecule’s carbon-fluorine chain, it is capped by a cluster of other atoms. Many types of PFAS molecules have heads made of a carbon atom connected to a pair of oxygen atoms, for example.

Dr. Dichtel came across a study in which chemists at the University of Alberta found an easy way to pry carbon-oxygen heads off other chains. He suggested to his graduate student, Brittany Trang, that she give it a try on PFAS molecules.

Dr. Trang was skeptical. She had tried to pry off carbon-oxygen heads from PFAS molecules for months without any luck. According to the Alberta recipe, all she’d need to do was mix PFAS with a common solvent called dimethyl sulfoxide, or DMSO, and bring it to a boil.

“I didn’t want to try it initially because I thought it was too simple,” Dr. Trang said. “If this happens, people would have known this already.”

An older grad student advised her to give it a shot. To her surprise, the carbon-oxygen head fell off.

It appears that DMSO makes the head fragile by altering the electric field around the PFAS molecule, and without the head, the bonds between the carbon atoms and the fluorine atoms become weak as well. “This oddly simple method worked,” said Dr. Trang, who finished her Ph.D. last month and is now a journalist.

For the full commentary see:

Carl Zimmer. “MATTER; Fighting Forever Chemicals With Chemicals.” The New York Times (Tuesday, Aug. 23, 2022): D3.

(Note: ellipsis, and bracketed date, added.)

(Note: the online version of the commentary has the date August 18, 2022, and has the title “MATTER; Forever Chemicals No More? PFAS Are Destroyed With New Technique.”)

The research summarized in the passages quoted above was published in:

Trang, Brittany, Yuli Li, Xiao-Song Xue, Mohamed Ateia, K. N. Houk, and William R. Dichtel. “Low-Temperature Mineralization of Perfluorocarboxylic Acids.” Science 377, no. 6608 (Aug. 18, 2022): 839-45.

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