TY - GEN A1 - Unger, Wolfgang A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas A1 - Schulze, Rolf-Dieter T1 - NEXAFS - spectroscopy on plasma-polymerized films prepared from organic molecules (ethylene, allyl alcohol, styrene) KW - Plasma KW - Beschichtung KW - Organische Filme KW - Röntgenabsorptionsspektroskopie PY - 2004 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2003.pdf#page=297 SN - 0179-4159 SP - 297 EP - 299 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-3478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas A1 - Unger, Wolfgang T1 - NEXAFS - spectroscopy on plasma-polymerised films prepared from organic molecules (Acrylic acid, allylamine, ethylene) KW - NEXAFS KW - Plasmapolymere KW - Synchrotronstrahlung PY - 2005 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2004.pdf#page=315 SN - 0179-4159 SP - 315 EP - 317 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-7387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang T1 - Aging of Plasma-Deposited Films Prepared from Organic Monomers N2 - Plasma-deposited polymer films were prepared from organic molecules and investigated using near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) for aging effects after exposure to air. Results from the investigation of homopolymers are summarized. Primarily the effect of the deposition parameters duty cycle and power are dealt with. The effect of the deposition parameter pressure is briefly discussed. An example to show the effect of feed gas composition on the aging of plasma polymerized ethylene/allyl alcohol and styrene/allyl alcohol copolymer is also given. In general, change in content of unsaturated or aromatic species, change in concentration of monomer functionality, and change in the oxygen content was observed in the plasma polymerized films on aging. KW - Plasma copolymer KW - ESCA/XPS KW - NEXAFS KW - Plasma polymerization PY - 2007 SN - 1612-8850 SN - 1612-8869 VL - 4 IS - S1 SP - S784 EP - S789 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-11934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas A1 - Schulze, Rolf-Dieter A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang T1 - Surface Analysis of Plasma-Deposited Polymer Films, 4 - In situ Characterization of Plasma-Deposited Ethylene Films by XPS and NEXAFS N2 - XPS and NEXAFS spectroscopy were used for the chemical characterization of pulsed plasma-deposited ethylene films before and after exposure to ambient air. The influence of external plasma parameters on the spectroscopic results was investigated. Information on the chemical character of the plasma-polymerized films, such as the regularity of the primary structure, the amount of long-living radicals, and branching or cross-linking or both was derived from this data. Irregularity and radical concentration for post-plasma reactions of the plasma-deposited films increased with the duty cycle or power. A decreased level of monomer fragmentation and, consequently, an increase in regularity is partially concluded from the experimental data when the monomer pressure is increased. The concentration of surface radicals available for post-plasma reactions also increased with monomer pressure. The correlation found between the degree of the post-plasma oxygen incorporation and the variation of the various external parameters agreed with earlier ToF-SSIMS findings. KW - ESCA/XPS KW - NEXAFS KW - Plasma polymerization KW - Polyethylene (PE) KW - Thin films PY - 2005 U6 - https://doi.org/10.1002/ppap.200400070 SN - 1612-8850 SN - 1612-8869 VL - 2 IS - 4 SP - 310 EP - 318 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-11940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas T1 - Radio frequency (r.f.) plasma-deposited polymer films: influence of external plasma parameters as viewed by comprehensive in-situ surface chemical analysis by XAS, XPS and ToF-SIMS N2 - The formation of plasma-deposited materials made from organic molecules is a technologically attractive way to obtain films with unique properties, e.g. adhesion, wettability, conductivity or selected chemical functionalization. A detailed chemical characterization of these films is a great challenge for the analyst because of the co-existence of a large number of chemical species in plasma-deposited films. We investigated these types of organic films using photoelectron spectroscopy for chemical analysis (ESCA, XPS), near edge X-ray absorption fine structure (NEXAFS) spectroscopy at synchrotron radiation source BESSY II and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). A dedicated plasma preparation chamber was designed and added to the main analysis chamber of the respective spectrometers. This approach offers the possibility of studying plasma-deposited films without exposure to air before analysis (often called in-situ analysis) and the influence of post-plasma reactions, i.e. the ageing process. The present investigations are aimed at finding correlations between basic chemical properties of the deposited films and the plasma deposition parameters, e.g. duty cycle in pulsed plasmas and the power of discharge. KW - Plasma deposition KW - NEXAFS KW - XPS KW - ToF-SIMS KW - Plasma parameter PY - 2006 U6 - https://doi.org/10.1002/sia.2158 SN - 0142-2421 SN - 1096-9918 VL - 38 IS - 4 SP - 522 EP - 525 PB - Wiley CY - Chichester AN - OPUS4-12271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oran, Umut A1 - Swaraj, Sufal A1 - Lippitz, Andreas A1 - Unger, Wolfgang T1 - Surface analysis of Plasma Deposited Polymer Films, 7: "In situ" Characterization of Plasma Deposited Allylamine Films by ToF-SSIMS, XPS and NEXAFS Spectroscopy N2 - Plasma deposited allylamine films were studied by in situ ToF-SSIMS, XPS and NEXAFS Spectroscopy before exposure to ambient air. The influence of external plasma parameters such as duty cycle, plasma power, and monomer flow rate on (i) unsaturation, (ii) branching and cross-linking, (iii) nitrogen surface concentration and (iv) retention of amino groups was investigated. Harder plasma conditions, which can be obtained when high duty cycles, high plasma power, and low monomer flow rates are employed, increase the unsaturated, branched and cross-linked character of the plasma deposited films, while the surface concentration of N as well as the retention of the monomer's amino group decrease. As proven by NEXAFS findings and cross-checked by ToF-SSIMS results, the allylamine monomer's primary amino groups are partially transformed into other nitrogen functionalities during its plasma polymerization. Amongst them imines and nitriles are the conversion products with the highest probabilities of formation. Another conversion channel is the formation of nitrogen species not participating in the film growth. This is the reason for an increased N loss in plasma deposited allylamine films as observed independently by XPS and ToF-SSIMS when the plasma parameters are changed from mild to hard. KW - Allylamine KW - NEXAFS KW - Plasma polymerization KW - ToF-SSIMS KW - XPS PY - 2006 U6 - https://doi.org/10.1002/ppap.200500168 SN - 1612-8850 SN - 1612-8869 VL - 3 IS - 3 SP - 288 EP - 298 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-12272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas A1 - Schulze, Rolf-Dieter A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang T1 - Surface Analysis of Plasma-Deposited Polymer Films, 2: Analysis of Post-Plasma Air Reacted Plasma Polymerized Styrene by X-Ray Photoelectron Spectroscopy and X-Ray Absorption Spectroscopy N2 - Chemical properties of plasma-polymerized styrene films can be effectively controlled by the appropriate choice of external plasma parameters, such as duty cycle, power and monomer pressure. Chemical properties here are the regularity of the primary structure, the amount of long living radicals and branching or cross-linking or both in plasma polymerized styrene films, which can be indirectly monitored by X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Principally, XPS and NEXAFS spectra of plasma-polymerized styrene show all the spectroscopic fingerprints characteristic of atactic polystyrene indicating an inherent similarity of the respective primary chemical structures. There is an increase in irregularity and radical concentration for the plasma deposited films with increasing duty cycle or power. With an increase in monomer pressure, a decreased level of monomer fragmentation and, consequently, an increase in regularity must be concluded from the experimental data. The applied power regulates the fragmentation of the monomers as monitored by spectroscopic signals correlated to the aromatic rings. A trend in the extent of the post-plasma oxygen incorporation according to the variation of the various external plasma parameters was deduced, which agrees with earlier ToF-SIMS findings KW - Chemical characterization KW - ESCA/XPS KW - NEXAFS KW - Plasma polymerization KW - Polystyrene PY - 2004 U6 - https://doi.org/10.1002/ppap.200400022 SN - 1612-8850 SN - 1612-8869 VL - 1 SP - 134 EP - 140 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-6935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang T1 - Study of influence of external plasma parameters on plasma polymerised films prepared from organic molecules (acrylic acid, allyl alcohol, allyl amine) using XPS and NEXAFS N2 - Plasma polymerised films of acrylic acid, allyl alcohol and allyl amine were prepared and studied by XPS (X-ray photoelectron spectroscopy) and XAS (X-ray absorption spectroscopy). The influence of external plasma parameters on certain chemical aspects of the films was investigated. The use of XPS and NEXAFS (near edge X-ray absorption fine structure) as complimentary tools in the surface characterisation of thin films has been highlighted. Certain chemical aspects of the plasma polymerised films such as presence of ROCdouble bond; length as m-dashO in the case of plasma polymerised acrylic acid films, presence of RCdouble bond; length as m-dashO and RC–OR bonds in case of plasma polymerised allyl alcohol films and presence of RCdouble bond; length as m-dashN and C?N in case of plasma polymerised allyl amine films were studied. The concentration of ROCdouble bond; length as m-dashO species was found to decrease with increase in r.f. duty cycle in the case of plasma polymerised acrylic acid films. In case of plasma polymerised allyl alcohol films there is a decrease in the concentration of RCdouble bond; length as m-dashO species and increase in the concentration of RC–OR species at higher pressures, while in the case of plasma polymerised allyl amine films the concentration of RCdouble bond; length as m-dashN and C?N increases at higher powers, with an increase in C?N more pronounced at higher powers. KW - Plasma polymerization KW - NEXAFS KW - XPS KW - Plasma parameter PY - 2005 U6 - https://doi.org/10.1016/j.surfcoat.2005.01.083 SN - 0257-8972 VL - 200 IS - 1-4 SP - 494 EP - 497 PB - Elsevier Science CY - Lausanne AN - OPUS4-11045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Friedrich, Jörg Florian A1 - Lippitz, Andreas A1 - Unger, Wolfgang T1 - Surface Chemical Analysis of Plasma-Deposited Copolymer Films Prepared from Feed Gas Mixtures of Ethylene or Styrene with Allyl Alcohol N2 - Plasma deposited styrene/allyl alcohol and ethylene/allyl alcohol copolymer films were prepared and characterized using XPS, NEXAFS and ToF-SIMS. The relative partial flow rates of the co-monomers are used as deposition process parameters to vary and all other process parameters were constrained to conditions optimized for retention of functional groups. By doing this it is possible to control certain chemical properties of the copolymer films such as unsaturation, oxygen and hydroxyl group relative surface contents. The aging behavior of the plasma copolymer films on air was studied, too. Non-linear variations of relative oxygen contents, contents of C—OR species and contents of carbonyl species are obtained vs. variation of feed gas composition for both monomer combinations. The chemical character of the plasma copolymer films varies between the limits given by the respective plasma homopolymers. The observed non-linear correlations are discussed in terms of approaches developed for classic radical copolymerization. The aging behavior of the different plasma copolymers films depends on the feed gas composition. Principally these aging phenomena known from plasma polymer aging studies of that respective monomer which dominates the character of the plasma copolymer are observed. KW - Plasma polymers KW - Plasma copolymers KW - XPS KW - NEXAFS KW - Allyl alcohol KW - ESCA/XPS KW - Plasma polymerization KW - ToF-SIMS PY - 2007 SN - 1612-8850 SN - 1612-8869 VL - 4 IS - 4 SP - 376 EP - 389 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-14846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Swaraj, Sufal A1 - Oran, Umut A1 - Lippitz, Andreas A1 - Unger, Wolfgang T1 - Surface Chemical Analysis of Plasma-Deposited Copolymer Films Prepared from Feed Gas Mixtures of Ethylene or Styrene with Allylamine N2 - Plasma deposited ethylene/allylamine and styrene/allylamine copolymer films were prepared and analyzed using XPS, NEXAFS and ToF-SIMS. The relative partial flow rate of the each monomer was used as the variable deposition parameter, while the other deposition parameters were kept constant at optimized values for the retention of functional groups. The effect of the variation in the relative partial flow rates of co-monomers on various chemical aspects of the films like unsaturation, nitrogen retention and branching was investigated revealing several non-linear correlations. This observation is taken as an indication for chemical copolymerization processes during film deposition. An attempt is made to compare these non-linear correlations with approaches which have been developed for classic radical copolymerization processes. The aging behavior of these plasma copolymer films was also studied; the results indicated a stabilization against oxidation in comparison to the aging of allylamine plasma homopolymers. KW - Ethylene-allylamine copolymer KW - ESCA KW - NEXAFS KW - Plasma polymerization KW - Styrene-allylamine copolymer KW - Surface characterization KW - TOF-SIMS KW - XPS PY - 2008 U6 - https://doi.org/10.1002/ppap.200700106 SN - 1612-8850 SN - 1612-8869 VL - 5 IS - 1 SP - 92 EP - 104 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-16466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -