A groundbreaking review article outlines principles for designing PFAS alternatives without their longest-lasting chemical bonds, paving the way for a transition away from ‘forever chemicals’ and towards more climate-friendly materials.
Scientists have been searching for alternatives to ‘forever chemicals,’ which are known to build up in the environment and in human bodies, causing a range of health issues. A new review article outlines principles to design PFAS alternatives without their longest-lasting chemical bonds.
Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals used in various consumer products, such as non-stick cookware, food packaging, and firefighting foam.
They have been widely used since the 1940s due to their water-repelling properties and durability.
However, research has shown that PFAS can contaminate soil, groundwater, and even drinking water, leading to potential health concerns.
The Problem with PFAS
PFAS, or per- and polyfluoroalkyl substances, show up in products as varied as firefighting foams, nonstick cookware, and stain-resistant fabrics. While none of the proposed substitutes outperform existing PFAS yet, the best alternatives are approaching the same performance in certain water-repelling applications.
PFAS usually contain long chains of carbon atoms, with most or all of the carbon atoms having strong bonds to one or more fluorine atoms. This makes them difficult to break down and leads to their accumulation in the environment and in human bodies.
Designing Fluorine-Free Surfactants
Researchers have found that by replacing fluorine-rich fragments with chains of mostly carbon and silicon atoms, they can create surfactants that work similarly to PFAS without the use of fluorine. These surfactants are better at reducing surface tension in water, making them suitable for applications such as foams that fight gasoline or grease fires.
Challenges Ahead
However, designing a surface coating that repels oils is much harder, and it’s difficult to compete with PFAS in this application without invoking fluorine. To effectively repel oils with fluorine-free surfaces, ‘we really do need a breakthrough,’ says Kevin Golovin, a mechanical engineer at the University of Toronto.
A New Era for Climate-Friendly Materials
The research could facilitate a transition away from PFAS in certain applications and help counter perceptions that PFAS cannot be replaced. As Martin Scheringer, a chemist at ETH Zurich, notes, ‘We need scientists, chemists, and materials scientists who break out of the PFAS track.‘ This new blueprint for designing PFAS alternatives could lead to more climate-friendly materials and a reduced risk of health problems associated with these chemicals.
- sciencenews.org | Scientists home in on alternatives to ‘forever chemicals’
