Iop Publishing Journal of Physics D: Applied Physics (original) (raw)
Related papers
Journal of Applied Polymer Science, 1999
Modification of polyolefin surfaces is often necessary to achieve improved printability, lamination, etc. Although corona discharge and flame treatments can produce the higher surface energy needed for these applications, the properties of the resulting surfaces are not always optimal. Atmospheric pressure plasma is a surface modification technique that is similar to corona discharge treatment, but with more control, greater uniformity, and higher efficiency. Using an atmospheric pressure plasma unit with a dielectric barrier discharge generated using an asymmetric pulse voltage, the effects of different gases, powers, and linespeeds on polyethylene surface treatment were studied. Our results show that atmospheric pressure plasma can be used to achieve higher long-term wettability, higher surface oxygen and nitrogen, and a greater range of surface chemistries with better robustness versus standard corona treatment. Atomic force microscopy results suggest significant differences in the mechanism of surface functionalization versus etching and ablation depending on the gases used.
Atmospheric-Pressure Dielectric Barrier Discharge for Surface Processing of Polymer Films and Fibers
IEEE Transactions on Plasma Science, 2000
Recently atmospheric pressure dielectric barrier discharge (APDBD) plays an important role in chemical, industrial and biological applications. It has been used for ozone synthesis, hydrogen production from natural gas, surface treatment including textile and polymer treatment, yeast and bacterial inactivation. The physics and mechanism of atmospheric pressure dielectric barrier discharge will be reviewed. Coaxial and planar DBD have been constructed for ozone production, textile treatment and yeast sterilization. Oxygen has been used as working gas for ozone production, while oxygen and argon will be used for yeast inactivation.
European Physical Journal-applied Physics, 2002
This paper is the third of a trilogy [16, 75] devoted to polystyrene thin film treatment under DC pulsed discharges conditions. In order to study the wettability variations (∆θ/θi) of the surface, N2-Ar or O2-Ar mixtures are used. The experimental conditions are close to the best running conditions deduced from [16, 75]. The pressure is varied from 1 mbar to 10 mbar and the mixture proportion from 0% to 100%. The importance of metastable states is pointed out. Reaction processes in the plasma and on the polystyrene surface are proposed in order to explain the surface activation and the formation of chemical bonds with nitrogen or oxygen. The best running conditions are reached when the generator frequency equals 500 Hz for a pressure about 4 mbar in nitrogen and 10 mbar in oxygen, whatever the gas mixture composition is. The wettability is better with oxygen than with nitrogen and the best value is reached for a duration time shorter in oxygen than in nitrogen. The minimum of treatment time necessary to reach the ∆θ/θi plateau value depends on the mixture composition.
Evaluation of a reel-to-reel atmospheric plasma system for the treatment of polymers
Surfaces and Interfaces, 2017
Plasma treatments are widely used to enhance the surface energy of polymers prior to bonding or the application of functional coatings. This study investigates the performance of a linear atmospheric pressure plasma source for the reel-to-reel treatment of polymer webs. The continuous argon plasma treatments were carried out on 15 cm diameter polyethylene terephthalate (PET) web substrates using the linear plasma source (Plamax), operating at 13.56 MHz. The study investigated how the processing parameters influenced the effectiveness of the plasma treatment in enhancing both the polymer web's water contact angle (WCA) and surface energy (SE). Based on these measurements the plasma treatment was found to yield a homogeneous level of activation across the 15 cm web, using a treatment speed of 0.9 m/min. The plasma discharge was monitored using both thermal imaging and optical emission spectroscopy (OES). The latter demonstrated how the oxygen species which diffuse into the argon plasma due to air ingress, were directly correlated with the level of polymer activation.
Surface and Coatings Technology, 2010
A micro-cavity discharge array (2500 cavities of 50 µm 2 size) was operated in neon at atmospheric pressure to modify polystyrene (PS), fluorinated ethylene-propylene co-polymer (FEP) and polytetrafluoroethylene (PTFE) polymer surfaces and, with the injection of a polymerisable monomer (acrylic acid), to deposit patterned, thin polymeric coatings. The aim of this study was to investigate the utility of these microdischarge sources in the surface treatment of polymers and for the patterned deposition of polymeric material. The influence of the driving frequency, treatment time and sample-array distance on polymer surface treatment was investigated. X-ray photoelectron spectroscopy (XPS) was used to explore the surface chemistry of the treated polymer surfaces and of the polymer deposits. It was found that increasing the micro-cavity discharge source driving frequency and/or treatment time and decreasing the sample-array distance all led to a significant decrease in surface energy as determined by water contact angle measurements. For a period of time, post treatment surface hydrophilicity degraded due to the well known "ageing effect" but stabilized after two days. Finally, it was demonstrated that the device could be used for the localized, array sized, deposition of acrylic acid. High resolution XPS analysis of the deposit registered a C 1s spectra typical of poly(acrylic acid) with a prominent peak centred at approximately 289.3 eV indicating a relatively high level retention of the original monomer functionality. These results demonstrate that microcavity discharges, operated at or near atmospheric pressure, can be used to both modify and locally deposit polymeric material.
Characterization of atmospheric pressure discharges
The interest towards atmospheric pressure discharges for plasma processing of materials is continuosly growing because of their technological advanteges respect to low pressure discharges. The development of new plasma source design and their application to processes of surface modification and functionalization of materials is actively pursued also in the plasma physics community. On the contrary, research aimed to the development of suitable diagnostics and process control tools is not so advanced and investigated. Indeed diagnostics of atmospheric pressure plasmas are very demanding because of the short temporal and the small spatial scales involved in the plasma state and in the different discharge regimes. Indeed such plasmas are often made up of intermittent and higly localized structures like stremers or microdischarges. We will presents results concerning the diagnostics of dielectric barrier discharges (DBD) operated in a streamer regime in a controlled high pressure gas mi...
We present a set-up consisting of parallel plate dielectric barrier discharge (DBD) and a dedicated electronic circuit. Using the dedicated electronic circuit a uniform glow-like discharge is generated in a process gas consisting of 20 % nitrogen in argon at a driving frequency of 380 kHz. The discharge is characterized by means of IV-measurements and CCD images. The discharge is used for surface treatment of polypropylene (PP). The set-up is configured in such a way that the treated PP also serves as the dielectric barrier of the DBD. The PP can be transported across the electrodes in a roll-to-roll process. The treated surface is characterized by means of contact angle measurements. The water contact angle of PP decreases from 100° to a saturated value of 30° within half a second of plasma treatment time. This decrease in water contact angle corresponds to an increase of the surface energy from 30 mJ/m 2 to 65 mJ/m 2 , which is entirely due to an increase in the polar component of...
Characterization of pulsed discharge plasma at atmospheric pressure
Surface and Coatings Technology, 2007
Experiments are performed to improve a pulsed corona discharge system for methane destruction at atmospheric pressure. The corona discharge is energized by 6-12 µs wide voltage pulses (0.3-7 kV) at a repetition frequency of 1.050 kHz. The characteristic of methane destruction is observed by a mass spectrometer. We have found that methane destruction depends on the parameters such as: pulse width, input pulse voltage, repetition frequency, discharge current and discharge time. The effects of argon gas on methane destruction were also observed. The structural geometry of the soot, resulting from discharge process, is observed by transmission electron microscope. The main aim of this study is to show that the discharge could help as for the production of hydrogen and carbon nanotubes.
Surface modification of polyethylene and polypropylene in atmospheric pressure glow discharge
Journal of Physics D: Applied Physics, 2005
An atmospheric pressure glow discharge (APGD) was used for surface modification of polyethylene (PE) and polypropylene (PP). The discharge was generated between two planar metal electrodes, with the top electrode covered by a glass and the bottom electrode covered by the treated polymer sample. The discharge burned in pure nitrogen or in nitrogen-hydrogen or nitrogen-ammonia mixtures. The surface properties of both treated and untreated polymers were characterized by scanning electron microscopy, atomic force microscopy, surface free energy measurements and x-ray photoelectron spectroscopy. The influence of treatment time and power input to the discharge on the surface properties of the polymers was studied. The ageing of the treated samples was investigated as well. The surface of polymers treated in an APGD was homogeneous and it had less roughness in comparison with polymer surfaces treated in a filamentary discharge. The surface free energy of treated PE obtained under optimum conditions was 54 mJ m −2 and the corresponding contact angle of water was 40˚; the surface free energy of treated PP obtained under optimum conditions was 53 mJ m −2 and the contact angle of water 42˚. The maximum decrease in the surface free energy during the ageing was about 10%.