A research team from the University of Toronto’s Faculty of Engineering has developed a new type of water- and oil-repellent surface coating that performs comparably to conventional non-stick materials, but contains significantly lower levels of environmentally harmful PFAS, or ‘forever chemicals’.

The Problem with PFAS

Since the invention of PTFE (commonly known as Teflon) in the 1930s, PFAS (per- and polyfluoroalkyl substances) have been widely used for their durable non-stick properties. These chemicals resist breakdown in the environment and can accumulate in living organisms, leading to concerns over toxicity, bioaccumulation, and links to serious health issues such as cancer and developmental defects. Despite increasing regulation, PFAS remain prevalent in everyday products including cookware, rainproof textiles, packaging materials, and cosmetics due to the lack of viable alternatives.

Introducing Nanoscale Fletching

To address this challenge, Professor Kevin Golovin and PhD student Samuel Au of the Durable Repellent Engineered Advanced Materials (DREAM) Laboratory developed a novel coating method known as nanoscale fletching. The technique involves attaching short chains of PDMS (polydimethylsiloxane) — a silicone-based material known for its biocompatibility — to a substrate surface. These chains function like nanoscale bristles.

To enhance oil-repelling performance, the team incorporated a minimal quantity of the shortest possible PFAS molecule — just one carbon atom with three fluorine atoms — at the tip of each PDMS bristle. This small molecular addition significantly boosts repellency while reducing the environmental impact associated with longer-chain PFAS.

Comparable Performance, Lower Risk

When tested on fabric samples, the coating achieved a grade of 6 on the AATCC oil repellency scale, equalling the performance of many standard PFAS-based coatings. According to the researchers, the short-chain PFAS used in this hybrid material does not bioaccumulate and is currently not targeted by regulatory bans. The material therefore offers a compelling balance between functionality and reduced environmental risk.

Potential for Design and Industry

This innovation holds significant potential for industries and designers looking to develop safer, more sustainable products. Applications could include stain-resistant furnishings, spill-proof fashion garments, and non-toxic, grease-repellent food packaging. As regulations tighten around PFAS use, materials like this may offer designers a viable alternative that meets both performance and sustainability criteria.

The research team is actively seeking industrial partners to help scale and commercialise the process, with the ultimate aim of eliminating PFAS altogether while maintaining — or exceeding — current performance standards.

Source: U of T Engineering News
Photo: Samuel Au