Surface modification with a remote atmospheric pressure plasma (original) (raw)
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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: dc glow …
Journal of Physics D …
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.
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.
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, 2021
Biaxially oriented polypropylene (BOPP) is a highly transparent polymer defined by excellent mechanical and barrier properties applicable in the food packaging industry. However, its low surface free energy restricts its use in many industrial processes and needs to be improved. The presented study modifies a BOPP surface using two different atmospheric-pressure plasma sources operating in ambient air and capable of inline processing. The volume dielectric barrier discharge (VDBD) and diffuse coplanar surface barrier discharge (DCSBD) were applied to improve the wettability and adhesion of the 1–10 s treated surface. The changes in morphology and surface chemistry were analyzed by SEM, AFM, WCA/SFE, and XPS, and adhesion was evaluated by a peel force test. Comparing both plasma sources revealed their similar effect on surface wettability and incorporation of polar functional groups. Additionally, higher surface roughness in the case of VDBD treatment contributed to slightly more eff...
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.
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.
Surface and Coatings Technology, 2008
In the present work, Poly (ethylene terephthalate) films have been exposed to glow discharge air plasma to improve their surface properties for technical applications. Surface energy values have been estimated using contact angle value for different exposure times and different test liquids. Surface composition and morphology of the films were analyzed by XPS and AFM. Crystallinity of the plasma treated samples were studied by XRD analysis. The improvement in adhesive strength was studied by measuring T-peel strength and lap shear strength tests. It was found that the plasma treatment modified the surfaces both in chemical composition and morphology. Change of chemical composition made the polymer surfaces to be highly hydrophilic, which mainly depends on the increase in oxygen-containing groups. The AFM and XRD observation showed that the surface roughness and crystallinity of the PET film increased due to plasma treatment.
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.
Surface and Coatings Technology, 2018
This work reports on surface modification of polyethylene terephthalate (PET) polymer by an atmospheric pressure plasma jet (APPJ) operated with argon. A distinguishable feature of this device is that it terminates with a conical horn-like nozzle. Three different nozzles diameters were employed with the purpose to obtain uniform surface modification over large area. Treatments in small 3D objects that fit inside the conical horn were also conducted. In this study, water contact angle (WCA) measurements and X-ray photoelectron spectroscopy (XPS) were performed to assess the samples wettability and the surface elemental composition, as well as, their radial distribution. Plasma-induced changes on the polymer surface morphology were evaluated by Atomic Force Microscopy (AFM). Electrical characterization of the plasma and investigation of the effect of the gas flow rate on the discharge power were carried out. After the plasma treatment PET surface became more hydrophilic over the entire area covered by the nozzle. This effect is caused by the incorporation of oxygen containing polar groups on the surface. It was also observed that depending on process parameters, the plasma treatment can extend even outside the area of the conical horn. The degree of surface modification depends on plasma dose while the treatment uniformity is determined mostly by the distance to the sample. Overall, a quite uniform surface modification was obtained over the entire area covered by the jet nozzle. Thus, the results suggest that by simply changing the jet geometry and choosing the right treatment parameters one can achieve a uniform treatment over an area whose size is determined by the horn diameter.