Study of polypropylene surface modification by air dielectric barrier discharge operated at two different frequencies

► Polypropylene was treated by filamentary DBD at two frequencies (60 Hz and 17 kHz). ► Both treatments formed water-soluble highly oxidized material on the surface. ► At the same energy dose the high-frequency DBD treatment was less aggressive. ► The 17 kHz DBD process introduced more oxygen atoms on the surface. ► Upon washing the plasma-treated samples did not exhibit hydrophobic recovery.