Research on Surface Modification of Polytetrafluoroethylene Coupled With Argon Dielectric Barrier Discharge Plasma Jet Characteristics

An argon dielectric barrier discharge (DBD) atmospheric-pressure plasma jet (APPJ) is designed and employed for surface modification of polytetrafluoroethylene (PTFE). The plasma diagnostics and dielectric surface analysis are coupled together to investigate the mechanisms of plasma modification. The discharge power is obtained by Lissajous figure, and electron excitation temperature (EET) is measured through an optical emission spectrum and calculated by a Boltzmann diagrammatic method. The surface properties of modified PTFE samples are characterized by the static contact angle, surface resistivity, scanning electron microscope (SEM), and X-ray photoelectron spectroscopy. The results show that the discharge power, EET, and surface wettability increase with the Ar flowing rate, and a slight decrease of surface resistivity is revealed after plasma treatment. The surface roughness of PTFE is enhanced, and the oxygen-containing hydrophilic groups are incorporated by the impacts of APPJ radical species. Moreover, the hydrophilicity of PTFE can be improved by a surface presanding process, particularly after APPJ treatment. Finally, the surface modification mechanisms of APPJ on PTFE are discussed.