20.500.12556/RUL-134842 Defluorination of polytetrafluoroethylene surface by hydrogen plasma Defluorination of polytetrafluoroethylene (PTFE) surface film is a suitable technique for tailoring its surface properties. The influence of discharge parameters on the surface chemistry was investigated systematically using radio-frequency inductively coupled H$_2$ plasma sustained in the E- and H-modes at various powers, pressures and treatment times. The surface finish was probed by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The measurements of water contact angles (WCA) showed increased wettability of the pristine PTFE; however, they did not reveal remarkable modification in the surface chemistry of the samples treated at various discharge parameters. By contrast, the combination of XPS and ToF-SIMS, however, revealed important differences in the surface chemistry between the E- and H-modes. A well-expressed minimum in the fluorine to carbon ratio F/C as low as 0.2 was observed at the treatment time as short as 1 s when plasma was in the H-mode. More gradual surface chemistry was observed when plasma was in the E-mode, and the minimal achievable F/C ratio was about 0.6. The results were explained by the synergistic effects of hydrogen atoms and vacuum ultraviolet radiation. polytetrafluoroethylene fluorine depletion hydrogen plasma VUV radiation surface modification hydrophilic true false true Angleški jezik Ni določen Članek v reviji 2022-02-04 09:30:54 2022-02-04 09:30:54 2022-09-14 04:10:16 0000-00-00 00:00:00 2020 0 0 14 str. iss. 12, art. 2855 Vol. 12 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 53 2073-4360 10.3390/polym12122855 39928579 RAZ_Vesel_Alenka_2020.pdf RAZ_Vesel_Alenka_2020.pdf 1 7C2F53C668975FC6486A0666B8757875 2c94781b880a9223e8a71c0c2c6a46b557434f5c4769cb05c5bd5f254dc41f28 1843cec2-8595-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=153532 https://www.mdpi.com/2073-4360/12/12/2855 0 bca65bfd-8594-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=153531 Naravoslovnotehniška fakulteta 0 0 0