PTFE Surface Etching in the Post‐discharge of a Scanning RF Plasma Torch: Evidence of Ejected Fluorinated Species

The texturization of poly(tetrafluoroethylene) (PTFE) surfaces is achieved at atmospheric pressure by using the post‐discharge of a radio‐frequency plasma torch supplied in helium and oxygen gases. The surface properties are characterized by contact angle measurement, X‐ray photoelectron spectroscopy and atomic force microscopy. We show that the plasma treatment increases the surface hydrophobicity (with water contact angles increasing from 115 to 155°) only by modifying the PTFE surface morphology and not the stoichiometry. Measurements of sample mass losses correlated to the ejection of CF2 fragments from the PTFE surface evidenced an etching mechanism at atmospheric pressure. magnified image