| AVS 59th Annual International Symposium and Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | T. Dufour, Université Libre de Bruxelles, Belgium |
| Authors: | T. Dufour, Université Libre de Bruxelles, Belgium J. Hubert, Université Libre de Bruxelles, Belgium N. Vandencasteele, Université Libre de Bruxelles, Belgium F. Reniers, Université Libre de Bruxelles, Belgium |
| Correspondent: | Click to Email |
Due to their extraordinary range of properties, polymeric materials play an essential and ubiquitous role in everyday life. Plasma-modifications of polymeric surfaces further extend the range of their applications, especially with fluoropolymers due to their widespread in biocompatibility and self-cleaning coatings applications.
The aim of our work is to compare the treatments carried out with two distinct plasma sources on a selection of fluoropolymers: PVF, PVDF, TrFE, PTFE, Nafion©, FEP and PFA. The first treatment is performed with a post-discharge generated by an RF plasma torch, supplied with a helium-oxygen mixture and operating at atmospheric pressure. The second treatment is achieved in the plasma phase of a DBD and operates at atmospheric pressure, also in the same gases. In both cases, we discuss the influence of the treatment time and of the O2 flow rate on the surface properties. A comprehensive study of the plasma/polymer interface has also been performed by mass spectrometry and optical emission spectroscopy to identify the species responsible of the surface texturization, i.e. the species breaking the atomic bindings on the surface top atomic layers.
The surface properties are characterized by determining the advancing and receding WCA so as to show if the treated polymers can be classified into the Wenzel or Cassie-Baxter models. The super-hydrophobicity of PTFE has already been achieved. Moreover, two liquid probes have been used: milliQ water (H2O) and diiodomethane (CH2I2) to discuss the validity of the Fowkes theory.
Finally, the XPS analyses give information on the surface composition which remains unchanged for the majority of the studied fluoropolymers. We will also explain how it is possible to identify the fragments ejected from the polymeric surfaces during the etching process by using the XPS instrument. CF2 fragments have already been evidenced in the case of the PTFE and different ones in the case of Nafion©.