TY - JOUR A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute T1 - Tailoring of polymer surfaces with monotype functional groups of variable density using chemical and plasma chemical processes N2 - Polymer surfaces were modified in low-pressure glow discharge plasmas for introduction of monotype functional groups of different type and density. For this purpose three ways are selected, (i) oxygen plasma treatment followed by wet-chemical reduction of O functional groups to OH groups, (ii) plasma bromination for introducing C - Br groups and (iii) coating by deposition of thin plasma (co-) polymerized layers of functional groups-bearing monomers with OH, NH2, COOH, epoxy etc. functionalities. Subsequently, these groups were used as anchoring points for chemical grafting of spacer molecules, oligomers, prepolymers, fluorescent labels, ionic and nucleic acid residues, employing different chemical routes. The yield in monosort functional groups at polymer surfaces ranged from 10–14 (process i), 20–40 (process ii) and 18–31 groups per 100 C atoms (process iii) as measured by XPS after derivatization. The consumption of functional groups amounted to 40–90% of all functionalities present at the surface and depended on the dimensions of grafted molecules. For infinitely variably tuning the number of functional groups process iii was performed as copolymerization of a functional group-carrying comonomer with a non-functionalized (“chain-extending”) comonomer. KW - Introduction of functional groups KW - Plasma modification KW - Reactions at Polymer surfaces PY - 2006 SN - 0340-255x SN - 1437-8027 VL - 132 SP - 62 EP - 71 PB - Springer CY - Berlin AN - OPUS4-12515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Schulz, Ulrich A1 - Kühn, Gerhard A1 - Erdmann, Jessica A1 - Möller, B. T1 - Glanzerhaltung von Autolacken - Verbessern der Lebensdauer eines 2K-Klarlacks durch Gasphasen-Fluorierung PY - 1999 SN - 0025-5300 VL - 41 SP - 375 EP - 378 PB - Carl Hanser Verlag CY - München AN - OPUS4-7284 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard T1 - Kontrolle der Plasmamodifizierung von Polymeroberflächen mittels ESCA PY - 1998 VL - 70 SP - 5 CY - Darmstadt AN - OPUS4-7285 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kühn, Gerhard A1 - Retzko, Iris A1 - Lippitz, Andreas A1 - Unger, Wolfgang A1 - Friedrich, Jörg Florian T1 - Homofunctionalized polymer surfaces formed by selective plasma processes N2 - Several possibilities exist to produce a modified polymer surface with a high density of only one sort of functional group such as: (i) the plasma grafting of unfragmented monomer molecules and their polymerization forms OH, NH2, COOH groups, etc. in concentrations of approximately 25 groups per 100 C atoms; (ii) selective plasma bromination provides 10–25 CBr groups; (iii) the plasma oxidation of polymer surfaces in an O2 plasma followed by the chemical reduction of all O-containing groups to OH groups by diborane, vitride™ (Na complex) or LiAlH4 yields 9–14 OH groups per 100 carbon atoms; and (iv) the grafting of spacers with different endgroups onto OH or CBr groups produces 7–10 spacer molecules/100 C. This work was focused on the formation of thin plasma deposited polymer layers with a maximum of (homo)functional groups and with a minimum of chemical irregularities using the pulsed plasma technique. The monomers were allylalcohol, allylamine, acrylonitrile and acrylic acid. The further intent was to study the interactions of functional groups (OH, COOH, NH2) and deposited metals (Cr, Al, Ti). It was expected that more basic (NH2), weakly basic or neutral (OH) or more acidic (COOH) groups would show different interactions and chemical reactions with metal atoms. KW - Pulsed plasma polymerization KW - Functional groups KW - Long-term stability KW - Polymer-metal composites PY - 2001 DO - https://doi.org/10.1016/S0257-8972(01)01056-8 SN - 0257-8972 VL - 142-144 SP - 494 EP - 500 PB - Elsevier Science CY - Lausanne AN - OPUS4-6971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Retzko, Iris A1 - Kühn, Gerhard A1 - Unger, Wolfgang A1 - Lippitz, Andreas T1 - Plasma polymers with chemically defined structures in contact with metals N2 - The retention of chemical structure and functional groups during plasma polymerization was investigated. Usually plasma polymer layers, prepared by a continuous wave radio-frequency plasma, are often chemically irregular in their structure and composition. To minimize these irregularities low wattages and the pulsed plasma technique were applied to avoid fragmentations. The first goal was to produce plasma polymers comprising double or triple bonds as precursors for electrically conducting polymers. Acetylene, ethylene, butadiene and polystyrene were used as monomers and deposited as thin polymer films by pulsed plasmas of low wattages. Styrene polymerization was strongly enhanced in the dark phase (plasma off) of a pulsed r.f. plasma caused by the reactivity of the vinyl-type double bond. This could be confirmed by a verification of a rather high chemical regularity of the film sample. The oxygen content of this film measured by X-ray photoelectron spectrometry (XPS) was in situ 0% and after 24 h exposure to air lower than 1%. Additionally, post-plasma oxidations of trapped radicals with air could be suppressed using NO gas as radical quencher. Such quenched plasma polymer layers were completely stable against oxidation for a number of weeks. During the low-wattage pulse plasma polymerization metal atoms were simultaneously or layer by layer evaporated into the growing layer and in situ measured by XPS. These metal atoms are acting as dopants. Here, Li, K, Mg and Cr were used at different concentrations providing electrical conductivity and magnetic properties for the film. KW - Pulsed plasma KW - Plasma polymerization KW - Doping with metal atoms KW - Encapsulation of nanoparticles PY - 2001 DO - https://doi.org/10.1016/S0257-8972(01)01051-9 SN - 0257-8972 VL - 142-144 SP - 460 EP - 467 PB - Elsevier Science CY - Lausanne AN - OPUS4-6972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Möller, B. A1 - Kühn, Gerhard A1 - Unger, Wolfgang A1 - Krüger, P. T1 - Improvement of adhesion properties of polymers by producing oxyfluorinated surfaces PY - 2001 SN - 0016-4232 VL - 92 IS - 5 SP - 1334 EP - 1444 PB - Leuze CY - Saulgau, Württ. AN - OPUS4-6973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang A1 - Lippitz, Andreas A1 - Koprinarov, Ivaylo A1 - Kühn, Gerhard A1 - Weidner, Steffen A1 - Vogel, Lydia T1 - Chemical reactions at polymer surfaces interacting with a gas plasma or with metal atoms - their relevance to adhesion N2 - The chemical and morphological stabilities of polymer segments in the near-surface layer were investigated by spectroscopic methods such as X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. Model studies were undertaken with Langmuir–Blodgett films, self-assembled monolayers and oligomer films. For thin polymer layers (30 to 500 nm), the changes in molecular-weight distributions of some polymers were investigated systematically by size exclusion chromatography, matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry and thermal-field flow fractionation for oxygen- and helium-plasma exposures. The polymer surfaces were found to be relatively stable at exposure to an oxygen low-pressure plasma up to ca. 2 s. This is important information to get maximum adhesion to metals in composites. In correlation to their redox potentials, potassium, aluminium and chromium react with oxygen functional groups at the polymer/metal interface. In a dedicated study, chromium was found to attack aromatic rings and form different reaction products. PY - 1999 DO - https://doi.org/10.1016/S0257-8972(99)00229-7 SN - 0257-8972 VL - 116-119 SP - 772 EP - 782 PB - Elsevier Science CY - Lausanne AN - OPUS4-6981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kühn, Gerhard A1 - Weidner, Steffen A1 - Decker, Renate A1 - Ghode, Archana A1 - Friedrich, Jörg Florian T1 - Selective surface functionalization of polyolefins by plasma treatment followed by chemical reduction N2 - Polymer surfaces can be finished with functional groups upon exposure to a plasma. Species of the plasma gas are attached at surface carbon atoms, forming functional groups of different composition. To produce a modified polymer surface with a high density and homogeneity of hydroxyl groups only, the oxygen-plasma-formed oxygen functional groups were chemically reduced by diborane and LiAlH4 with yields of 10 to 11 OH groups per 100 carbon atoms in the 3 to 5 nm near-surface layer as detected by X-ray photoelectron spectroscopy (XPS). The identification of hydroxyl groups was performed by means of attenuated total reflectance–Fourier transform infrared spectroscopy and XPS. KW - Attenuated total reflectance-Fourier transorm infrared spectroscopy KW - Chemical reduction of functional groups KW - Plasma modification KW - X-ray photoelectron spectroscopy PY - 1999 DO - https://doi.org/10.1016/S0257-8972(99)00232-7 SN - 0257-8972 VL - 116-119 SP - 796 EP - 801 PB - Elsevier Science CY - Lausanne AN - OPUS4-6983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Kühn, Gerhard A1 - Friedrich, Jörg Florian T1 - Infrared-Matrix-assisted Laser Desorption/Ionization and Infrared-Laser Desorption/Ionization Investigations of Synthetic Polymers PY - 1998 SN - 0951-4198 SN - 1097-0231 VL - 12 SP - 1373 EP - 1381 PB - Wiley CY - Chichester AN - OPUS4-6988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Kühn, Gerhard A1 - Decker, Renate A1 - Roessner, D. A1 - Friedrich, Jörg Florian T1 - Influence of Plasma Treatment on the Molar Mass of Poly(ethylene terephthalate) Investigated by Different Chromatographic and Spectroscopic Methods N2 - The influence of different types of low and atmospheric pressure plasma on poly(ethylene terephthalate) (PET) has been studied in terms of changes in molar mass and molar mass distribution. Apart from a variation of plasma gases (oxygen, helium) different types of plasma (microwave, radio frequency, corona discharge) were used for the plasma surface modification. The changes in molar mass and types of functional end groups of lower molar mass products were investigated by means of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOFMS), whereas the high-molar mass fraction was analyzed by means of size-exclusion chromatography (SEC). The formation of crosslinked products during exposure to a helium plasma, which emits preponderately energy-rich and intense ultraviolet radiation, was proved by means of thermal field-flow fractionation (ThFFF). This method combined with a multiangle laser light scattering (MALLS) detector allows detection of weakly crosslinked polymers and microgels. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1639-1648, 1998 KW - Poly(ethylene terephthalate) KW - PET KW - Plasma PY - 1998 UR - http://www3.interscience.wiley.com/cgi-bin/abstract/36482/ABSTRACT DO - https://doi.org/10.1002/(SICI)1099-0518(19980730)36:10<1639::AID-POLA17>3.0.CO;2-H SN - 0360-6376 SN - 0887-624X VL - 36 IS - 10 SP - 1639 EP - 1648 PB - Wiley CY - Hoboken, NJ AN - OPUS4-6989 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -