| AVS 56th International Symposium & Exhibition | |
| Thin Film | Monday Sessions |
| Session TF2-MoA |
| Session: | Thin Films: Growth and Characterization II |
| Presenter: | L. Denis, University of Mons, Belgium |
| Authors: | L. Denis, University of Mons, Belgium D. Thiry, University of Mons, Belgium D. Cossement, Materia Nova Research Center, Belgium P. Gerbaux, University of Mons, Belgium F. Brusciotti, Vrije Universiteit Brussel, Belgium I. Van De Keere, Vrije Universiteit Brussel, Belgium V. Goossens, Vrije Universiteit Brussel, Belgium H. Terryn, Vrije Universiteit Brussel, Belgium M. Hecq, University of Mons, Belgium R. Snyders, University of Mons, Belgium |
| Correspondent: | Click to Email |
Primary amine-based plasma polymer films (PPF) attract increasing interest in biotechnology since they have recently been reported to support cell growth and biomacromolecule (DNA, polysaccharides) immobilization. Since many years, the PPF chemistry has extensively been studied. Nevertheless, the behavior of these materials in solvents is not yet fully understood. For example, some works have reported the decrease of allylamine PPF thickness (Δd) after immersion in ethanol. Such a kind of observation is frequently attributed to the loss of material in the solvent. Up to now, however, such assumption remains unproved and therefore this phenomenon needs further investigations.
In this work, allylamine PPF have been synthesized at low pressure (2.67 Pa) using pulsed radiofrequency discharges varying the mean power injected in the plasma (Pmean). The PPF behavior in ethanol has been studied through analysis of both PPF and the resulting ethanol solution characteristics.
Δd which is inversely proportional to Pmean has been measured by ellipsometry. This behavior has been attributed to the increase of the PPF cross-linking density (dXL) with Pmean. In order to evaluate dXL, we have used Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and further treatment of the data by Principal Component Analysis (PCA). The results suggest an increase of dXL with Pmean, hence supporting our assumption. Moreover, it should be noted that the PPF chemistry, evaluated by X-ray Photoelectron Spectroscopy (XPS), does not change significantly after ethanol immersion.
On the other hand, the ethanol solution has been analyzed by Gas Chromatography – Mass Spectrometry (GC-MS), a highly sensitive method (10-9 g/ml). The results show that there are no chemical species released by the PPF during immersion.
Therefore, our set of data suggests that Δd, observed after PPF immersion in ethanol, is mostly related to reorganization of the PPF structure and not to material dissolution in the solvent.