A team of engineers of theUniversity of Toronto has developed a new coating non -stick capable of rejecting both water and oil with an effectiveness comparable to Teflon, but without using the Pfas – The notorious perfluoroalchilic chemicals connected to serious health problems and environmental contamination. The discovery, published in the magazine Nature Communicationsrepresents an important step forward in the search for more secure alternatives to traditional coatingswith potential applications ranging from kitchen pans to technical fabrics.
For decades, the non-stick surfaces have relying on the PFAS-synthetic molecules characterized by carbon-fluorary bonds, extremely resistant and able to reject almost any substance. However, many of these compounds – such as the PFOAemployed in the historical versions of Teflon – have been associated with Tumors, congenital defects and accumulation in the human body. Even the shorter chain variants, although less dangerous, remain persistent in the environment.
The turning point came thanks to Polidimetylsilossano (PDMS)a silicone polymer already widely used in medical devices and contact lenses. Although biocompatible and heat resistant, the PDMS alone is not effective in rejecting the oil. To remedy the problem, the researcher Samuel au And his team developed a technique called nanoscal flexinginspired by the structure of the feathers that stabilize the flight of an arrow.
This technique consists inAdd tiny groups -CF₃ (a carbon atom linked to three fluorine atoms) at the ends of the molecular chains of the PDMS. These groups spontaneously migrate to the surface of the material, creating an extremely repellent external barrier, similar to that of the coatings containing PFAS.
High performance, minimum toxicity
The test results are surprising: the new coating has obtained a Score 6 on the AATCC Scala of Oil’s Valencyequal to that of the best coatings containing PFAS, but with a quantity of fluorine drastically lower.
The -cf₃ group is the shorter among the existing PFAS and, according to current research, such as its long chain counterparties. The mixture tends to degrade in trifluoroacetic acida substance that the body easily eliminates and that presents one much lower toxicity Both for human beings and for aquatic fauna.
During the tests, the coating has maintained its effectiveness also on difficult surfaces such as porous fabrics, metals, networks and aluminum. Remained stable below jets of water, exposure to temperatures up to 200 ° C and even in acid or basic environments. Even after being subjected to continuous splashes of oil, the material continued to reject the liquids, keeping a dry surface Much longer than conventional silicones.
Towards a future without PFAS
Despite the encouraging results, Some experts warn that even short chain pfas such as the -CF₃ are not completely harmless. Tripluoroacetic acid, for example, is resistant to environmental degradation and its long -term impact is still the subject of study. However, the authors of the study underline that the quantities used in the coating are extremely reduced: The potential emissions of an entire treated jacket are equivalent to just over an hour of loss of refrigerant gases by a car air conditioning.
In light of European Union proposals to prohibit thousands of PFAS compoundsthis material represents a Realistic transitory solution. The research team recognizes that the final goal remains to create a top -free coating without PFAS, but highlights that this discovery shows how the Resellence to liquids is not linked to the length of the fluorinated chainas it was believed so far.
The path to a future free from “Eternal chemicals” It is still long, but thanks to this new technology, The industry could finally have an effective and less toxic alternative to traditional non -stick coatings.
