TY - GEN A1 - Welzel, F. A1 - Grunewald, Thomas A1 - Beyer, M. A1 - Grätz, Rainer A1 - Klages, C.-P. T1 - Mechanisch erzeugte Reib- und Schlagfunken im Vergleich T2 - 12. Kolloquium zu Fragen der chemischen und physikalischen Sicherheitstechnik CY - Berlin, Deutschland DA - 2010-06-15 PY - 2010 SN - 978-3-9813550-1-7 SN - 0938-5533 SP - 32 EP - 36 PB - BAM Bundesanstalt für Materialforschung und -prüfung CY - Berlin AN - OPUS4-21266 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hinze, A. A1 - Klages, C.-P. A1 - Zänker, A. A1 - Thomas, M. A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - ToF-SIMS imaging of DBD-plasma-printed microspots on BOPP substrates N2 - Imaging ToF-SIMS has been applied to characterize the surface chemistry variations across small areas produced by a DBD-type plasma printing technique on a BOPP substrate using pure nitrogen and a nitrogen-hydrogen gas mixture. CH4N+ and CNO- secondary ions are detected with high yields remote from the discharge region. They are discussed to be due to surface modifications of the substrate by metastable gas-phase species. On the other hand, surface species exist that are preferentially formed by reactions of the substrate with short-lived species which are only present close to the plasma discharge region. A C3H8O+ secondary fragment ion is assumed to be a key fragment of such a surface species. KW - ToF-SIMS KW - Plasma KW - Polymer KW - Dielectric barrier discharges (DBD) KW - Plasma printing KW - Polymer modification KW - Surface modification KW - Time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) imaging PY - 2008 U6 - https://doi.org/10.1002/ppap.200700138 SN - 1612-8850 SN - 1612-8869 VL - 5 IS - 5 SP - 460 EP - 470 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-19342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Khosravi, Z. A1 - Kotula, S. A1 - Lippitz, Andreas A1 - Unger, Wolfgang A1 - Klages, C.-P. T1 - IR- and NEXAFS-spectroscopic characterization of plasma-nitrogenated polyolefin surfaces N2 - Modification of polyethylene and polypropylene surfaces by atmospheric-pressure plasmas using mixtures of nitrogen and hydrogen was studied using Fouriertransform infrared spectroscopy in the attenuated total reflection mode (FTIR-ATR) and by near-edge x-ray absorption fine structure spectroscopy (NEXAFS) in order to shed some light on the chemical nature of nitrogen-containing functional Groups on the polymer surface. Using FTIR-ATR spectroscopy combined with hydrogendeuterium isotope exchange of active hydrogen atoms, it was shown that the direct treatment of PE foils by dielectric barrier discharges (DBDs) in N2/H2 mixtures and a subsequent exposure of the samples to the ambient air results in the formation of –NH2 moieties of primary amides on the polymer surface. Corresponding in situ experiments with streaming N2/H2 DBD post-discharges virtually free of H2O and O2, on the other hand, showing the absence of –NH2, proving that no primary amines or amides are formed by this treatment although substantial amounts of nitrogen are incorporated. Moreover, directly N2/H2-plasma-treated polymer surfaces, similar to afterglow-treated low-density polyethylene (LDPE), show amphiphilic character as to be seen by chemical derivatization with nucleophilic reagents 4-(trifluoromethyl) phenylhydrazine and 4-(trifluoromethyl)benzylamine, in addition to electrophilic aromatic aldehydes normally used to derivatize such surfaces. The presence of imines or other functional groups with CN moieties which may be invoked to explain the dual (amphiphilic) reactivity is proven by NEXAFS studies on ultrathin plasma-treated PE films, confirming significant amounts of nitrogen in CN bonds and carbon in CC bonds. KW - X-ray spectroscopy KW - IR spectroscopy KW - Plasma-nitrogenated polyolefin surfaces KW - Unsaturated CN bonds KW - NEXAFS PY - 2017 U6 - https://doi.org/10.1002/ppap.201700066 SN - 1612-8869 SN - 1612-8850 VL - 15 IS - 1 SP - e1700066, 1 EP - 15 PB - WILEY-VCH Verlag GmbH & Co. KGaA, CY - Weinheim AN - OPUS4-43786 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -