Researchers at the Technical University of Berlin have developed a new class of silicon-based superacids that could mark a breakthrough in dealing with PFAS ("per- and polyfluorinated alkyl substances"). These chemicals, often referred to as "eternity chemicals", are extremely persistent, are widely used in outdoor clothing, non-stick coatings and construction products, for example, and are considered a health risk. They can promote cancer, impair fertility and weaken the immune system. Until now, there has been no effective method of breaking their stable carbon-fluorine bonds.
The superacids created in the UniSysCat Cluster of Excellence are among the strongest of their kind. They are novel Lewis acids with a special structure - silicon atoms in combination with halogens and organic residual groups. This structure gives the acids an extreme "electron hunger". As a result, they can attack and break even the exceptionally stable bonds of PFAS.
Hope closer to being able to control and break down PFAS pollution in the environment and industry in future
Another advantage: the substances are not consumed in the degradation process, but regenerate like catalysts. This opens up prospects for efficient and sustainable recycling processes in terms of green chemistry.
The development shows how theoretical concepts from chemistry - such as the definition of Lewis acids from 1923 by the US chemist Gilbert N. Lewis - are enabling concrete industrial applications almost a century later. The new superacids bring closer the hope of being able to control and reduce PFAS pollution in the environment and industry in the future.
Source: ingenieur.de
