In this work we report the surface modification of different engineering polymers, such as, polyethylene terephthalate (PET), polyethylene (PE) and polypropylene (PP) by an atmospheric pressure plasma jet (APPJ). It was operated with Ar gas using 10 kV, 37 kHz, sine wave as an excitation source. The aim of this study is to determine the optimal treatment conditions and also to compare the polymer surface modification induced by plasma jet with the one obtained by another atmospheric pressure plasma sourcethe dielectric barrier discharge (DBD). The samples were exposed to the plasma jet effluent using a scanning procedure, which allowed achieving a uniform surface modification. The wettability assessments of all polymers reveal that the treatment leads to reduction of more than 40• in the water contact angle (WCA). Changes in surface composition and chemical bonding were analyzed by x-ray photoelectron spectroscopy (XPS) and Fourier-Transformed Infrared spectroscopy (FTIR) that both detected incorporation of oxygen-related functional groups. Surface morphology of polymer samples was investigated by Atomic Force Microscopy (AFM) and an increase of polymer roughness after the APPJ treatment was found.The plasma-treated polymers exhibited hydrophobic recovery expressed in reduction of the O-content of the surface upon rinsing with water. This process was caused by the dissolution of low molecular weight oxidized materials (LMWOMs) formed on the surface as a result of the plasma exposure.

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Atmospheric pressure plasma jet was used to deposit polymer films from argon/air/acetylene mixture. Depending on the gas composition, three modes of operation were observed and characterized. The film deposited by a stationary jet had a circular shape with area (where thickness was almost constant) about the nozzle inner diameter. The deposition rate of stationary jet decreased with the time: a film of 2 μm was obtained after the first two minutes, while in the next two minutes only 1.3 μm film was deposited. The plasma polymers were characterized by infrared spectroscopy, where variety of C\ \H and few C\ \O bonds were detected. By using a linear displacement system, we obtained homogeneous deposition over a larger area with deposition rate of about 330 nm/ min, showing the potential of such plasma jet system for large-scale depositions.

In this study, the hybrid corona-dielectric barrier discharge plasma treatment was employed to modify the physical, chemical and morphological characteristics of a half-knitted fabric composed of 92% polyamide 6.6 and 8% elastane (PA). These properties of the fabric were evaluated by the water contact angle, x-ray diffraction, infrared spectroscopy, scanning electron microscopy and atomic force microscopy techniques. In addition, the dyeing and washing processes were also investigated. A significant reduction of the contact angle was observed for plasma-treated PA. Infrared spectroscopy analyses indicated that C-H, N-H, and NO groups in PA increased after plasma treatment, explaining the improved coloring strength for the plasma-treated samples when dyed with reactive and acid dyes. A better fixation of dye was also observed after the atmospheric plasma treatment. Furthermore, dyeing with a basic and acid dye caused the dyeability increases for the plasma-treated sample compared with the untreated sample.

Atmospheric pressure plasma jet operated in argon was utilized to modify surfaces of glass, acrylic, and PTFE dielectrics. This paper describes the influence of the dielectric substrate on operation and properties of plasma. Two modes of operation (each of those have two patterns) were described. The transition from one mode to another, values of the dissipated power, and spreading of plasma over the dielectric surfaces strongly depended on the substrate material. Additionally, three methods of plasma spreading estimation were presented and discussed.