Oleksandr Galmiz

Permanent hydrophilization of outer and inner surfaces of polytetrafluoroethylene tubes using ambient air plasma generated by surface dielectric barrier discharges

We present an atmospheric pressure ambient air plasma technique developed for technically simple treatment of inner and/or outer surfaces of plastic tubes and other hollow dielectric bodies. It is based on surface dielectric barrier discharge generating visually diffuse plasma layers along the treated dielectric surfaces using water-solution electrodes. The observed visual uniformity and measured plasma rotational and vibrational temperatures of 333 K and 2350 K indicate that the discharge can be readily applied to material surface treatment without significant thermal effect. This is exemplified by the obtained permanent surface hydrophilization of polytetrafluoroethylene tubes related to the replacement of a high fraction (more than 80%) of the surface fluorine determined by X-ray photoelectron spectroscopy. A tentative explanation of the discharge mechanism based on high-speed camera observations and the discharge current and voltage of measurements is outlined.

Study of surface dielectric barrier discharge generated using liquid electrodes in different gases

Surface dielectric barrier discharges with conductive water-solution electrodes were generated at atmospheric pressure air, nitrogen, oxygen, and argon. The discharges were studied by conventional and high-speed camera photography. Plasma rotational and vibrational temperatures and the electron number density were estimated using optical emission spectroscopy. Surprisingly, especially for oxygen, the discharge was found to generate visually diffuse strongly non-isothermal plasma. This observation indicates the interesting application potential of the discharge for surface plasma treatments of, i.e. the inner and outer surfaces of hollow dielectric bodies.

Underwater discharge plasma-induced coating of poly(acrylic acid) on polypropylene fiber

An underwater diaphragm discharge generated at atmospheric pressure by high voltage pulses was used for plasma polymerization of acrylic acid and simultaneously for the deposition of polymer coating on polypropylene multifilament fibers. The deposition process was monitored by Fourier transform infrared spectroscopy in combination with scanning electron microscopy. Possible schemes of polymerization are suggested also.

Plasma treatment of polyethylene tubes in continuous regime using surface dielectric barrier discharge with water electrodes

Combining the surface dielectric barrier discharges generated in contact with water based electrolytes, as the discharge electrodes, we have designed a new type of surface electric discharge, generating thin layers of plasma which propagate along the treated polymer surfaces. The technique was aimed to achieve uniform atmospheric pressure plasma treatment of polymeric tubes and other hollow bodies. The results presented in this work show the possibility of such system to treat outer surface of polymer materials in a continuous mode. The technical details of experimental setup are discussed as well as results of treatment of polyethylene tubes are shown.

Dielectric barrier discharge generated from the liquid electrolyte

Summary form only given. The water plasmas generated by atmospheric discharges have already demonstrated their potencial also for surface modification of polymer materials and are emerging as a very flexible concept to generate selective functionalized polymer surface. We have developed a novel type of surface dielectric barrier discharge generating thin layers of visually diffuse plasmas along the treated polzmer polymer using water-based electrolyte as a electrodes. This technique has been designed particularly to achieve uniform treatment of outer or inner suface of polymeric tubes and other hollow bodies (e.g. tubes, containers, flasks, catethers). Especially the treatment of inner surface of tubes is a serious challenge for atmospheric pressure plasma processing. In our work we focused on functionaliyation of polzmeric surface, grafting with biocompatible materials and increasing novel properties. The discharge was energized by a sinusoidal alternating current and high voltage power supply with 15-20 kV amplitude and 25-30 kHz frequency. In our experiments PTFE tube (outer diameter - 8mm) was inserted vertically into water-based electrolyte (5% solution of oxalic acid) and filled by the same solution. Both electrically insulated volumes of solution serve as a liquid electrodes. The surface dielectric barrier discharge is always generated from the contact line of the lower liquid surface with dielectric wall of PTFE tube, so in principle the simple control the level of inner or outer surface liquid can change the location of inner and/or outer plasma treatment. During the plasma treatment the tube was moved vertically up. The diffuse plasma layer was generated in ambient air with an unspecified content of water and electrolyte molecules evaporated by the discharge. After treatment the strong and stable hzdrophylic treatment was observed. This was exemplified by the permanent surface oxidation and replacement of a high fraction of the surface determined by XPS.

Deposition of Zn-containing films using atmospheric pressure plasma jet

Abstract The purpose of this work was to deposit Zn-containing films on Si substrates using the commercial atmospheric pressure plasma jet “kINPen’09.” In preliminary experiments Zn-containing films were deposited on the silicon substrates immersed in water solutions of Zn(NO3)2•6H2O salt. The surface composition of deposited films was analyzed by the XPS (X-ray photoelectron spectroscopy) technique while the bulk composition was studied by means of XRD (X-ray diffraction) mesurements. The film thickness was measured by a profilometer. We have determined that the concentration of the zinc nitrate solution as well as changes in the deposition time resulted in a large fluctuation of the deposited film thickness. However, the successful deposition of the Zn-containing films on the Si substrate was definitely confirmed. Graphical Abstract