Surface modification with a remote atmospheric pressure plasma: dc glow … (original) (raw)
Related papers
Journal of Physics D-applied Physics, 2005
A remote atmospheric pressure discharge working with ambient air is used for the near room temperature treatment of polymer foils and textiles of varying thickness. The envisaged plasma effect is an increase in the surface energy of the treated material, leading, e.g., to a better wettability or adhesion. Changes in wettability are examined by measuring the contact angle or the liquid absorptive capacity. Two regimes of the remote atmospheric pressure discharge are investigated: the glow regime and the streamer regime. These regimes differ mainly in power density and in the details of the electrode design. The results show that this kind of discharge makes up a convenient non-thermal plasma source to be integrated into a treatment installation working at atmospheric pressure.
Surface modification with a remote atmospheric pressure plasma
Czechoslovak Journal of Physics, 2004
A remote atmospheric pressure DC glow discharge is used for the treatment of polymer foils. The envisaged plasma effect is an increase in the surface energy of the treated material, leading e.g. towards a better wettability or adhesion. In this research, poly(ethylene terephthalate)-foil (PET) is used as the material to be treated. Changes in wettability are examined by measuring the contact angle. The homogeneity of the treatment over the sample area is examined and correlated to the distribution of the current density in the plasma. The results show that this kind of discharge is a good candidate as a plasma source to be integrated in a treatment installation working at atmospheric pressure, having the advantage of a homogeneous treatment, insensitive to the thickness and density of the treated materials.
Plasmas and Polymers, 2002
Novel types of non-thermal plasma sources at atmospheric pressure based on multi-pin DC (direct current) diffusive glow discharge and AC (alternative current) streamer barrier corona have been elaborated and tested successfully for cold surface treatment of polymer films [polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET),] and polyester fabric. Results on physical properties ofdischarges mentioned and output energy characteristics of new plasma sources as well as data on after-treatment changes in wettability of films and fabrics are presented. The main goal of this study was to find out the experimental conditions for gas discharge and surface processing to achieve a remarkable wettability change for a short treatment time.
Effect of Glow-Discharge Air Plasma Treatment on Wettability of Synthetic Polymers
Journal of Surface Engineered Materials and Advanced Technology, 2012
Main aim of this study was focused on characterization of the effect of microwave air plasma treatment on wettability of synthetic polymer surfaces. Wettability of solid polymer surfaces polyethylene, polypropylene, polystyrene (PE, PP, PS) was followed as a function of plasma treatment time. For evaluation the equilibrium contact angles of wetting as well as dynamic contact angles of wetting were determined by means of sessile drop and Wilhelmy plate methods. Free surface energy (SFE) of studied samples were calculated from the experimentally determined contact angles using Fowkes and van Oss, Chaudhury and Good (vOCG) approaches. It was found that with prolonged treatment time the total surface free energy of PE was two times increased from 23 mJ/m 2 to 45 mJ/m 2 after 360 s plasma treatment time (calculated for W and EG as wetting liquids). Similar effect was found for all studied polymers. With respect to the dispersive and polar components of the total surface free energy the vigorous effect was found for polar component, for which it was increased from 7 mJ/m 2 to 20 mJ/m 2 .
Polymers Surface Treatment by Cold Atmospheric Plasma in Air
Cold atmospheric plasma (CAP) is a non equilibrium ionized gas formed by a collection of charged particles, radicals and UV radiations. In many applications, polymers suffer from hydrophobicity and low surface energy, this can be remediate by applying CAP to polymers' surfaces. Plasma may add large numbers of functional groups on polymeric surfaces giving them interesting properties without using environmentally unfriendly chemicals. In this work, an Atmospheric pressure plasma jet (APPJ) is constructed and operated in a DC mode by applying high voltage up to 5500 V between two coaxial electrodes separated by a ceramic insulator. APPJ is applied to different polymers' types as polypropylene (PP), polyurethane (PU) and polycarbonate (PC) using air as working gas. Polymers' samples of PP, PU and PC are exposed to plasma for different time intervals and at different distances from plasma. Polymeric surface wettability is measured by water drop contact angle method on polymer surface. Contact angles are found to decrease with increasing plasma treatment time and decreasing distance. This indicates wettability improvement by plasma treatment measured for different polymers considered. Induced chemical changes on polymers surface by plasma are investigated by Fourier Transform Infrared Spectroscopy (FTIR) analysis. FTIR provide chemical structure of polymer surface layer and changes in layer structures caused by plasma treatment. Noticeable amount of hydrophilic CO and C=O bonding species were created on the polymer surface after treatment. IR thermal camera results show moderate temperature increase on polymer surface during plasma treatment.
ATMOSPHERIC PLASMA TREATMENTS IN CONVERTING AND TEXTILE INDUSTRIES
2008
There are many current and emerging adhesion issues which require an additional process to enhance interfacial surface properties. Materials which are non-polar, such as polymers, have low surface energy and therefore typically require surface treatment to promote adhesion. One way of increasing surface energy and reactivity is to bombard a polymer surface with ions. This is achieved by the surface treatment with plasma. Basically, a plasma treater ionizes a gas mixture in an electromagnetic field. The ionized gas is then discharged on the polymer surface, increasing the presence of chemical functional groups on it. Among surface treatments, corona discharge is the most common method. Typically used for thin webs, corona treaters utilize air as working gas. For treating complex surfaces, atmospheric plasma glow discharge treatment is often the best approach. This plasma offers stable, more uniform and longer-lasting surface energy enhancement than corona discharge. In particular, plasma provides a critical advantage when processing steps are required for enhancing the properties of very low energy and reactivity surfaces, such as non-polar polyolefins. Many materials, in fact, require surface treatments to adhere to inks and coatings. Promoting adhesion is made even more challenging with the use of water-based coatings, which have higher surface tension than solvent coatings and thus even less tendency to wet-out on a polymer surface. The aim of our book is a discussion about the use of corona discharge and emerging atmospheric plasma treatments in several applications within converter and textile industries. Amelia Sparavigna, Rory A. Wolf
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.
Generation of Thin Surface Plasma Layers for Atmospheric-Pressure Surface Treatments
Contributions to Plasma Physics, 2004
Thin layers of atmospheric-pressure non-equilibrium plasma can be generated by pulse surface corona discharges and surface barrier discharges developing on the treated surfaces or brought into a close contact with the treated surfaces. Plasma sources based on these discharge types have the potential of meeting the basic on-line production requirements in the industry and can be useful for a wide range of surface treatments and deposition processes including continuous treatment of textiles. Comparing with atmospheric pressure glow discharge sources, the potential advantages of these plasma sources include their simplicity, robustness, and capability to process in a wide range of working gases.
Surface and Interface Analysis, 2010
This study focuses on the surface treatment of polymer films (polypropylene and polyethylene terephthalate) with a remote atmospheric pressure d.c. glow discharge operating in ambient air. The set-up used can be easily upgraded to industrial dimensions and simulates in-line processing due to the rotating drum used to mount the samples on. The discharge was characterized by measuring the voltage-current curve. From this curve, three regimes can be distinguished: corona regime, glow regime and spark regime. The voltage is adjusted so that the plasma operates in the glow regime and the treatment effects are analyzed by water contact angle and XPS measurements. It is shown that the remote plasma source is capable of reducing the contact angle and making the surface of the polymers more hydrophilic. The influence of the distance of the sample to the electrodes and the power is studied. By XPS measurements, the chemical composition of the surface after treatment is determined for different operating conditions. On none of the analyzed samples, nitrogen was detected. The main effect of the treatment is the incorporation of oxygen. Angle-resolved XPS measurements show that the composition of the top atomic layers is significantly different from that of the underlying layers. The functional groups grafted by the plasma treatment were identified by the deconvolution of the C1s peak.
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.