Cover Picture: Plasma Process. Polym. 6∕2015

Abstract

Front Cover: An atmospheric pressure diffuse dielectric barrier discharge between cylindrical rotary electrodes was applied for deposition of silica‐like moisture barrier films on polymer foil. The discharge was operated in N2/O2/Ar gas mixture with the addition of tetraethyl orthosilicate. It is shown that high quality permeation barrier films can be deposited by atmospheric pressure roll‐to‐roll process. Further details can be found in the article by Sergey A. Starostin et. al. http://doi.wiley.com/10.1002/ppap.201400194.

Synergy Between Plasma‐Assisted ALD and Roll‐to‐Roll Atmospheric Pressure PE‐CVD Processing of Moisture Barrier Films on Polymers

“…As recently discussed, [8] the porosity and barrier properties of silica films have been found to be controlled by the specific energy delivered per precursor molecule (TEOS) in the discharge plasma. Higher specific energy values result in denser films but this typically goes at the -6 -expense of the deposition rate.…”

“…[8] The schematic picture of the setup is shown in Figure 1a. In this system a high current diffuse reactor, process, and material properties can be found elsewhere.…”

“…The SiO 2 films employed in the present work were deposited at a relatively high rate of 1600 nm•min -1 and a specific energy of about 1 keV per TEOS molecule. By means of XPS and ATR-FTIR analysis it was observed [8] that such rapidly As a comparison, the performance of thin alumina layers deposited directly on PEN is shown in Figure 3. The relatively thick PA-ALD alumina film deposited on PEN has a similar barrier improvement as the silica-alumina bi-layers.…”

Infrared gas phase study on plasma-polymer interactions in high-current diffuse dielectric barrier discharge

“…7 The uniformity of the plasma and the high power density make this technology of high applied value in surface treatment as well as in thin film deposition, and excellent SiO 2 -like barrier layers on polymeric substrates have been achieved. 3,8,9 Distinct regimes of plasma-polymer interactions along the electrodes were identified with AFM and SEM, and it was concluded that during the film growth process a competition between deposition and etching exists. 10 It is well known that the deposition, or the polymerization process, is very complex as numerous intermediates such as ions and radicals are generated, which can interact with the polymer surface.…”

“…[1][2][3] In order to deposit uniform thin films, it is preferable to obtain homogeneous or "glow-like" plasma, which is usually limited to a few noble gases (e.g., helium and argon) under atmospheric pressure. [4][5][6] In our previous research, a high-current "glowlike" discharge was obtained in air-like gas mixture of N 2 /Ar/ O 2 under atmospheric pressure.…”