A new method for filtering PFOS and PFOA out of water has been developed by an international team, as reported in Angewandte Chemie International Edition. The method uses ring-shaped molecules with a functionalised rim, which allows for very efficient and selective filtration.

The problem of PFAS contamination is well-known, but the focus is now shifting to finding solutions. Take water purification, where PFAS (and pretty much everything that floats through water) is partly captured by, for example, activated carbon. ‘Activated carbon is neither selective nor very efficient’, says Han Zuilhof, professor of organic chemistry at Wageningen University & Research and Tianjin University in China. ‘You can extract PFAS with it, but the capacity is low and it is effectively one-time use.’ Zuilhof and his team have now created molecules that do a much better job: deca-ammonium-functionalised pillar[5]arenes.