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 JF - Plasma processes and polymers 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 DO - 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 - Oran, Umut A1 - Swaraj, Sufal A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang T1 - Surface Analysis of Plasma-Deposited Polymer Films, 3: In situ Characterization of Plasma-Deposited Ethylene Films by ToF-SSIMS JF - Plasma processes and polymers N2 - Pulsed-plasma-deposited ethylene films were studied by time-of-flight static secondary ion mass spectrometry (ToF-SSIMS) before and after exposure to ambient air. The influence of the external plasma parameters on the secondary ion mass spectra of plasma-deposited ethylene films was investigated. From these data, information on the chemical character of the plasma-deposited ethylene films was derived. The investigation of the effect of external plasma parameters on the chemical character of the plasma-deposited ethylene films revealed that there were some drastic changes in the secondary ion mass spectra of the films. It was found that fragmentation and re-arrangement of the monomer molecules in the plasma, which affects the chemical character of the deposited films, vary according to the external plasma parameters. When the plasma polymers are exposed to air, extensive oxygen incorporation occurs. The oxygen uptake is high at the beginning and then it levels of. Some indications for the formation and decay of peroxy radicals (COO) and, subsequently, hydroperoxides (COOH) are found. It was observed that the oxygen uptake of the plasma deposited ethylene films increase when the plasma conditions become harder. KW - Ageing KW - Plasma polymerization KW - Polyethylene (PE) KW - ToF-SIMS PY - 2004 DO - https://doi.org/10.1002/ppap.200400025 SN - 1612-8850 SN - 1612-8869 VL - 1 SP - 141 EP - 152 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-6936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -