| AVS 60th International Symposium and Exhibition | |
| Advanced Surface Engineering | Wednesday Sessions |
| Session SE+PS-WeA |
| Session: | Atmospheric Pressure Plasmas |
| Presenter: | N. Vandencasteele, Université Libre de Bruxelles, Belgium |
| Authors: | N. Vandencasteele, Université Libre de Bruxelles, Belgium J. Bossert, Université Libre de Bruxelles, Belgium A. Kakaroglou, Vrije Universiteit Brussel, Belgium B. Nisol, Université Libre de Bruxelles, Belgium H.A. Terryn, Vrije Universiteit Brussel, Belgium F.A.B. Reniers, Université Libre de Bruxelles, Belgium |
| Correspondent: | Click to Email |
Plasma polymerization is now commonly used to deposit a wide variety of films for various applications (corrosion protection, biocompatibility, ultrahydrophobic layers…). Atmospheric plasma polymerization is a very promising technique for thin film deposition in industry. Indeed it does not require the use of organic solvent and it is not limited by vacuum requirement. Furthermore the high reactivity of the plasma medium allows for a rapid deposition of a large number of molecules on virtually any kind of substrate.
However there are still some issue remaining: the degree of crosslinking is not always sufficient to ensure good barrier and mechanical properties of the films. In some instance the adhesion of the films to the substrate is not strong enough. In this study we looked at the plasma polymerization of Allyl methacrylate on gold substrate using a high frequency (17 kHz) dielectric barrier discharge (DBD). The effects of the classical plasma polymerization parameters (monomer concentration, power, deposition time…) are studied as well as the effect of in situ ultra violet (UV) irradiation. The UV source is a mercury discharge lamp commonly used to cure polymers. Our experimental setup consists of a 2 mm thick quartz plate (acting as the dielectric) covered with a stainless steel grid (diameter 0.018 mm, spacing 0.045 mm) acting as the powered electrode. The second electrode is made of a grounded copper plate. It is separated from the powered electrode by a 3mm gap. The UV lamp is placed directly above the quartz electrode, illuminating the sample trough the grid. Argon is used as the plasma gas. Its flow ranges from 1 to 3 liter per minute (LPM). The precursor vapor is carried in the plasma by a secondary argon line with flow ranging from 1 to 3 LPM. The total gas flow is kept constant at 4 LPM.
Three separates cases are studied: plasma polymerized films (pp-film) without UV irradiation, pp-films with post plasma UV irradiation and finally pp-films with UV irradiation during the plasma polymerization.
The pp-films are characterized by FTIR, XPS, contact angle and ellipsometry. Differences between the pp-film compositions have been evidenced for the 3 types of treatments. Increased O/C ratios have been observed for the films exposed to UV irradiation. The FTIR spectra are also strongly affected by the presence of UV irradiation. Changes in the C=O/C-C peaks ratio are observed for the 3 types of treatments. This allows us to conclude that the irradiation during the films growth leads to different results than the usual UV post treatment (UV curing).