TY - JOUR A1 - Farag, Zeinab Ramadan A1 - Friedrich, Jörg Florian A1 - Krüger, Simone A1 - Hidde, Gundula A1 - Moustapha, M. E. T1 - Adhesion promotion of thick polyphosphate-poly(allylamine) films onto polyolefin substrates by plasma polymers N2 - The adhesion of thick poly(allylamine)-polyphosphate layers (1 µm) deposited by the wet-chemical layer-by-layer technique (LbL) onto polyethylene or polystyrene (each 100 µm) was very low. To promote the adhesion of these LbL layers the polyolefin substrates were oxidized at the surface by short exposure to the oxygen plasma (2 or 5 s) and subsequently coated with an interlayer of plasma-deposited poly(allylamine) or poly(allyl alcohol) (100 nm). The plasma polymer interlayers have improved strongly the adhesion between polyolefin substrates and polyphosphate coatings. Such phosphate coatings are interesting for life sciences (nucleotide formation) but also for fire retardancy in combination with N-rich compounds such as melamine. The intention was to prefer chemical and hydrogen bonds for adhesion promoting because of their high binding energy. Therefore, the introduced oxygen-containing groups at the polyolefin surface could interact with the OH or NH2 groups of the adhesion-promoting plasma polymer interlayer. These groups were also able to interact strongly with the poly(allylamine)-polyphosphate topcoating. The coated polyolefins were investigated using Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance mode (FTIR-ATR), X-ray Photoelectron Spectroscopy (XPS), Thermo-Gravimetric Analyses (TGA) and Atomic Force Spectroscopy (AFM) and 90° peel test. KW - Plasma-polymerized poly(allylamine) KW - Adhesion KW - Layer-by-layer deposition KW - Plasma polymerization PY - 2016 UR - http://www.tandfonline.com/doi/abs/10.1080/01694243.2015.1095626 DO - https://doi.org/10.1080/01694243.2015.1095626 SN - 1648-4142 VL - 30 IS - 3 SP - 231 EP - 246 PB - Taylor & Francis AN - OPUS4-35885 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Hidde, Gundula A1 - Lippitz, Andreas A1 - Unger, Wolfgang T1 - Plasma bromination of graphene for covalent bonding of organic molecules N2 - Plasma-chemical bromination applied to graphitic materials, in particular to highly ordered pyrolytic graphite is reviewed. The resulting bromination efficiency of the plasma-chemical treatment was subject of systematic process optimization. The plasma of elemental bromine vapour produced bromine concentrations on graphene surfaces of more than 30 % Br/C using either inductively or capacitively coupled low-pressure radio-frequency plasmas. Plasma brominated graphite surfaces have been studied by Near Edge X-ray Absorption Fine Structure, X-ray Photoelectron Spectroscopy, Atomic Force Microscopy and Scanning Electron Microscopy. The introduction of bromine into graphene-like graphite layers and its binding situation were investigated. To study the physical effect of the plasma bromination process, Kr plasma was also used because of its chemical inertness but similar atomic mass. Covering the samples with a Faraday cage or with a LiF window should help to differentiate between physical, chemical and radiation effects of the plasma. Bromination was assigned to radical or electrophilic addition of bromine onto fully substituted aromatic double bonds (sp² C) with exothermal reaction enthalpy. Low bromination shows a strong decay of aromatic double bonds, higher bromination percentage let disappear all aromatic rings. The formed C–Br bonds were well suited for efficient grafting of organic molecules by post-plasma wet-chemical nucleophilic substitution. This grafting onto the graphene surface was demonstrated using aminosilane and different diamines. The bromination of double bonds changes the hybridization of carbon atoms from plane sp² to tetrahedral sp³ hybridization. Thus, the plane topography of graphene is destroyed and the conductivity is lost. KW - Graphene KW - Bromination KW - Grafting of diamines KW - Plasma KW - Organic graphting PY - 2014 DO - https://doi.org/10.1007/s11090-013-9509-x SN - 0272-4324 VL - 34 SP - 621 EP - 645 PB - Plenum Publ. Corp. CY - New York, NY, USA AN - OPUS4-30575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Farag, Zeinab A1 - Moustapha, M. A1 - Hidde, Gundula A1 - Friedrich, Jörg A1 - Azzam, M. A1 - Krüger, Simone ED - Mital, K.L. T1 - Promotion of Adhesion of Green Flame Retardant Coatings onto Polyolefins by Depositing Ultra-Thin Plasma Polymer Films N2 - Various methods have been used for introducing fire retardant additives into polymers. Deposition of thick fire retardant coatings directly onto polymer substrates is an alternative technique. An important advantage of the coating technique is the preservation of the physical and chemical integrity of the polymer material. Moreover, the fire retardancy of the polymer materials can be achieved following their production. Suitable coating materials are inorganics, intumescent, char-forming, oxygendiluting, and cooling or radical quenching layers. The most important problem is to achieve sufficient coating thickness to withstand the direct attack of flame and to protect the polymer bulk from pyrolysis, otherwise blistering of coating, caused by emitted pyrolysis gases, is often observed. To avoid blistering of coating, the adhesion between polyolefin substrate and fire retardant coating has to be extraordinarily high. In order to achieve such a high level of adhesion, the polymer surface has to be modified with adhesion-promoting functional groups. The deposition of thin plasma polymers as adhesion-promoting layers with NH2, OH or COOH groups has been the most suited method. These functional groups are able to form covalent bonds and other interactions between the fire-resistant coating and the plasma-modified polyolefin substrate. Additionally, the plasma polymer counteracts the strong mechanical stresses in the laminate on exposure to high temperatures by its flexibility. KW - Plasma KW - Adhesion PY - 2017 SN - 978-1-119-40748-5 SN - 978-1-119-40638-9 DO - https://doi.org/10.1002/9781119407485 VL - 2 SP - 399 EP - 427 PB - Scrivener Publishing CY - Beverly, USA AN - OPUS4-47227 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Simone A1 - Friedrich, Jörg A1 - Hidde, Gundula A1 - Farag, Zeinab R. A1 - Moustapha, Moustapha E. A1 - Azzam, Maged M. T1 - Promotion of adhesion of green flame retardant coatings onto polyolefins by depositing ultra-thin plasma polymer films: A critical review N2 - Various methods have been used for introducing fire retardant additives into polymers. Deposition of thick fire retardant coatings directly onto polymer substrates is an alternative technique. An important Advantage of the coating technique is the preservation of the physical and chemical integrity of the polymer material. Moreover, the fire retardancy of the polymer materials can be achieved following their production. Suitable coating materials are inorganics, intumescent, char-forming, oxygendiluting, and cooling or radical quenching layers. The most important problem is to achieve sufficient coating thickness to withstand the direct attack of flame and to protect the polymer bulk from pyrolysis, otherwise blistering of coating, caused by emitted pyrolysis gases, is often observed. To avoid blistering of coating, the adhesion between polyolefin Substrate and fire retardant coating has to be extraordinarily high. In order to achieve such a high level of adhesion, the polymer surface has to be modified with adhesion-promoting functional groups. The deposition of thin plasma polymers as adhesion-promoting layers with NH2, OH or COOH groups has been the most suited method. These functional groups are able to form covalent bonds and other interactions between the fire-resistant coating and the plasma-modified polyolefin substrate. Additionally, the plasma polymer counteracts the strong mechanical stresses in the laminate on exposure to high temperatures by its flexibility. The thick fire retardant coatings were chosen based on “green” ecological aspects to avoid flame-initiated emission of toxic or corrosive gases and remains of toxic char. KW - Flame retardant KW - Adhesion KW - Coating PY - 2016 DO - https://doi.org/10.7569/RAA.2016.097314 SN - 2168-0965 SN - 2168-0973 VL - 4 IS - 4 SP - 417 EP - 447 PB - Scrivener Publishing LLC AN - OPUS4-48164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zeynalov, Eldar A1 - Wagner, M. A1 - Friedrich, Jörg Florian A1 - Magerramova, M. A1 - Salmanova, N. A1 - Hidde, Gundula A1 - Meyer-Plath, A. T1 - The peculiar behavior of functionalized carbon nanotubes in hydrocarbons and polymeric oxidation environments N2 - It has been shown that selected types of substituents are able to vary the oxidative behavior of multi-walled carbon nanotubes. Such substituents investigated were sterically hindered secondary amino groups bonded in grafted piperidine units and covalently bonded bromine groups. Their interference and activity was preliminary determined in the model cumene and then in oil diesel fraction and low density polyethylene oxidation reactions. Results obtained indicate that chemical linking of amine moieties containing –NH groups directly to the carbon nanotubes core significantly increases their intrinsic anti-oxidative capacity while the grafting of Br-groups provokes the opposite functioning of the pristine samples. This inference was proved by thermogravimetric and differential thermal analysis of the polyethylene composites and experiments on profound aerobic oxidation of petroleum naphthenic fraction derived from the commercial Baku oils blend diesel cut. KW - Multi-walled carbon nanotubes KW - Amine derivatives KW - Plasma-chemical technique KW - Brominated carbon nanotubes KW - Rate of model oxidation KW - Anti-oxidative efficiency KW - Catalytic activity KW - Inhibition rate constant KW - Photoelectron spectroscopy KW - Oxidation KW - Polyethylene composites KW - Oil diesel fraction PY - 2016 DO - https://doi.org/10.1080/01694243.2016.1239304 SN - 0169-4243 SN - 1568-5616 VL - 31 IS - 9 SP - 988 EP - 1006 AN - OPUS4-39894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wettmarshausen, Sascha A1 - Kühn, Gerhard A1 - Hidde, Gundula A1 - Mittmann, Hans-Ulrich A1 - Friedrich, Jörg Florian T1 - Plasmabromination - the Selective Way to Monotype Functionalized Polymer Surfaces N2 - In contrast to other plasma modification processes of polymer surfaces, the bromination is very selective and shows a high yield in C—Br groups. The most convenient bromination process was found using bromoform, which was thus preferred to elemental bromine, allyl bromide, vinyl bromide or tert-butylbromide. The bromoform process give yields in C—Br up to 40 C—Br or more, with only 2-3% co-introduction of O-functionalities whereas allyl bromide results in yields of about 20 C—Br and more, but in more than 10% oxygen-containing by-products. C—Br groups serve as anchoring points for grafting of molecules, oligomers and pre-polymers of diole or diamine character. KW - Functional groups KW - Grafting KW - Plasma bromination KW - Polymer surfaces KW - Selective plasma process KW - Spacer PY - 2007 DO - https://doi.org/10.1002/ppap.200700019 SN - 1612-8850 SN - 1612-8869 VL - 4 IS - 9 SP - 832 EP - 839 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-16209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wettmarshausen, Sascha A1 - Min, Hyegeun A1 - Unger, Wolfgang A1 - Jäger, Christian A1 - Hidde, Gundula A1 - Friedrich, Jörg Florian T1 - Significance of hydrogen-deuterium exchange at polyolefin surfaces on exposure to ammonia low-pressure plasma N2 - Since more than 40 years ammonia plasma exposure of polyolefins is used for introduction of primary amino groups. The selectivity of this reaction and the yield in primary amino groups was found to be low. Here, a prominent side-reactions of this process was investigated, the hydrogenation by NH3 plasma. For identification of hydrogenation ammonia (NH3) and deuterated ammonia (ND3) were exposed to Polyethylene (h-PE) and fully deuterated polyethylene (d-PE) as well as hexatriacontane (h-HTC) and fully deuterated hexatriacontane (d-HTC) as low-molecular weight model for PE. H–D exchange was assumed and detected by Time-of-Flight Secondary Ion Mass Spectrometry (ToF–SIMS), X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflectance (ATR-FTIR) and 1H and 2H Nuclear magnetic Resonance. Results show a significant H–D exchange within the sampling depth of ATR (2.5 µm). However, N- and NH2 introduction was limited to the topmost surface as shown by SIMS and XPS (a few nanometers). KW - Deuterated ammonia KW - Ammonia plasma KW - Deuterated polyolefins KW - Hexatriacontane KW - H-D exchange PY - 2011 DO - https://doi.org/10.1007/s11090-011-9304-5 SN - 0272-4324 VL - 31 IS - 4 SP - 551 EP - 572 PB - Plenum Publ. Corp. CY - New York, NY, USA AN - OPUS4-24178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Wettmarshausen, Sascha A1 - Meyer-Plath, Asmus A1 - Ziemann, Sylvia A1 - Hidde, Gundula A1 - Zeynalov, Eldar T1 - Plasmabromierung von graphitischen Materialien - Kovalente Anbindung organischer Moleküle N2 - Die hochselektive und ausbeutereiche plasmachemische Bromierung von Polyolefinoberflächen wurde auf graphitische Materialien übertragen. Oberflächen von graphenartigem Highly Oriented Pyrolytic Graphite (HOPG), natürlichem Graphit, mehrwandige Kohlenstoffnanoröhren (MWCNT) sowie Kohlenstoff-Fasern wurden im Bromdampfplasma behandelt. Während die Bromierung von Polyolefinoberflächen als radikalische Wasserstoffabstraktion mit nachfolgender Addition (Rekombination) oder durch nucleophile Substitution an sp³-hybridisierten C-Atomen abläuft, können graphitische Strukturen sowohl an sp³-hybridisierten Strukturdefekten als auch durch elektrophile Addition an vollständig C-substituierte aromatische Doppelbindungen bromiert werden. Dabei werden die planaren (graphitischen) sp²-C-Atome in die tetraedrische sp³-Hybridisierung umgewandelt und zu elektrisch nichtleitenden Strukturen gefaltet. Die maximalen Bromausbeuten bei Verwendung von Brom als Plasmamedium lagen je nach Substrat zwischen 10–50% Br/C, mit Bromoform deutlich darüber, was durch Kombinationen von Bromoform mit Brom oder Allylbromid mit Bromoform durch Schichtbildung auf über 70% Br/C gesteigert werden konnte. An die C-Br-Gruppen wurden nasschemisch verschiedene Amine nucleophil gepfropft. Die Pfropfausbeuten von 1–10 Moleküle je 100 C lagen deutlich niedriger als die erreichten Pfropfgrade von etwa 1–22 Moleküle je 100 C-Atome an Polyolefinoberflächen. Da nach der chemischen Pfropfung nahezu alle nichtgepfropften Br-Gruppen verschwunden waren, muss auf eine bevorzugte Rekonstruktion der planaren sp²-Graphitschicht geschlossen werden. KW - Polymerbromierung PY - 2012 DO - https://doi.org/10.1002/vipr.201200481 SN - 0947-076X SN - 1522-2454 VL - 24 IS - 1 SP - 24 EP - 29 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25518 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zeynalov, Eldar A1 - Friedrich, Jörg Florian A1 - Hidde, Gundula A1 - Ibrahimov, H.J. A1 - Nasibova, G.G. T1 - 1Brominated carbon nanotubes as effective catalysts for petroleum hydrocarbons aerobic oxidation KW - Katalyse KW - Paraffinoxidation PY - 2012 SN - 0342-5622 VL - 38 IS - 1 SP - 45 EP - 48 PB - Urban-Verl. CY - Hamburg; Wien AN - OPUS4-25636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zeynalov, Eldar A1 - Friedrich, Jörg Florian A1 - Meyer-Plath, Asmus A1 - Hidde, Gundula A1 - Nuriyev, L. A1 - Aliyeva, A. Z. A1 - Cherepnova, Y. T1 - Plasma-chemically brominated single-walled carbon nanotubes as novel catalysts for oil hydrocarbons aerobic oxidation N2 - Brominated single-walled carbon nanotubes [(Br)n-SWCNT) produced by the plasma-chemical technique were involved in the liquid-phase process of hydrocarbons aerobic oxidation. The significant catalytic effect of the (Br)n-SWCNT was revealed at first by the cumene initiated model oxidation and then in experiments on profound aerobic oxidation of petroleum naphthenic fraction derived from the commercial Azerbaijan (Baku) oils blend diesel cut. The ability of (Br)n-SWCNT to accelerate the aerobic oxidation of the hydrocarbons was found out for the first time. Obviously this phenomenon originates from the peculiarities of electronic configuration of the (Br)n-CNT patterns. The plausible mechanism of (Br)n-SWCNT catalytic action is inclined to the formation of reactive oxygen species. The catalytic activity of (Br)n-SWCNT markedly exceeds the activity of the industrial catalysts, manganese salt of indigenous petroleum acids, used for the liquid phase petroleum hydrocarbons oxidation process. KW - Brominated carbon nanotubes KW - Plasma-chemical technique KW - Model cumene oxidation KW - Oxidation rate KW - Oxidation catalysts KW - Oil hydrocarbons liquid-phase oxidation KW - Manganese naphthenate KW - Synthetic petroleum acids PY - 2013 DO - https://doi.org/10.1016/j.apcata.2013.01.003 SN - 0926-860X SN - 1873-3875 VL - 454 SP - 115 EP - 118 PB - Elsevier CY - Amsterdam AN - OPUS4-28290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohamed, Zeinab A1 - Krüger, Simone A1 - Hidde, Gundula A1 - Schimanski, A. A1 - Jäger, Christian A1 - Friedrich, Jörg Florian T1 - Deposition of thick polymer or inorganic layers with flame-retardant properties by combination of plasma and spray processes N2 - Mixtures of hexamethyldisiloxane (HMDSO) and oxygen have been used for deposition of SiO2-like layers by plasma polymerization under low-pressure conditions onto polyethylene and polystyrene used as basecoat. Water glass was cast onto these 0.5 µm plasma thick siloxane-like layers with a thickness of 5 to 40 µm. The adhesion of these bilayer systems and their flame resistance were tested. The effect of different plasma parameters such as monomer/gas ratio, pressure and power input into the discharge on the deposition rate and the composition of the formed layers was studied. Characterization and chemical composition of the formed films were performed using infrared, X-ray photoelectron and solid state nuclear magnetic resonance spectroscopy. Peel strengths of composites were measured and the locus of peel front propagation was detected. Thermal properties of composites were analyzed by thermo-gravimetric analysis. Finally, the fire-retardant properties of thick coated polymers were determined by exposure to flames and the behavior of coatings on the polymers during flaming was observed visually. KW - Plasma polymerization KW - Hexamethyldisiloxane plasma polymer KW - Polystyrene KW - Polyethylene KW - Flame retardancy PY - 2013 DO - https://doi.org/10.1016/j.surfcoat.2013.04.039 SN - 0257-8972 VL - 228 SP - 266 EP - 274 PB - Elsevier B.V. CY - Lausanne AN - OPUS4-28735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lukowiak, M.C. A1 - Wettmarshausen, Sascha A1 - Hidde, Gundula A1 - Landsberger, Petra A1 - Boenke, Viola A1 - Rodenacker, K. A1 - Braun, Ulrike A1 - Friedrich, Jörg Florian A1 - Gorbushina, Anna A1 - Haag, R. T1 - Polyglycerol coated polypropylene surfaces for protein and bacteria resistance N2 - Polyglycerol (PG) coated polypropylene (PP) films were synthesized in a two-step approach that involved plasma bromination and subsequently grafting hyperbranched polyglycerols with very few amino functionalities. The influence of different molecular weights and density of reactive linkers were investigated for the grafted PGs. Longer bromination times and higher amounts of linkers on the surface afforded long-term stability. The protein adsorption and bacteria attachment of the PP-PG films were studied. Their extremely low amine content proved to be beneficial for preventing bacteria attachment. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-325406 DO - https://doi.org/10.1039/c4py01375a SN - 1759-9954 SN - 1759-9962 VL - 6 IS - 8 SP - 1350 EP - 1359 AN - OPUS4-32540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altmann, Korinna A1 - Schulze, Rolf-Dieter A1 - Hidde, Gundula A1 - Friedrich, Jörg Florian T1 - Elektrospray-Ionisation (ESI) - Lochfreie elektrophoretische Abscheidung von ultra-dünnen Polymerschichten N2 - Die Elektrospray-Ionisations (ESI)-Vernebelung von Polymerlösungen wird analytisch zur massenspektrometrischen Bestimmung der Molmassen von Makromolekülen genutzt. Dabei werden die Polymermoleküle nach einem speziellen Mechanismus im Hochspannungsfeld unter Normaldruckbedingungen vereinzelt und in das Massenspektrometer überführt. Dieser Prozeß kann auch zur flächigen Abscheidung einzelner Polymermoleküle genutzt werden. Die Struktur und Zusammensetzung sowie die Molmassenverteilung der Polymere bleiben dabei erhalten. Schichten polarer oder ionischer Polymere der Dicke einer Quasi-Monolage bis hin zu mehreren 100 Nanometern können abgeschieden werden. Erwähnenswert ist, daß der ESI-Prozeß zu den elektrophoretischen Verfahren gehört, was die Ausbildung lochfreier Schichten auf elektrisch leitenden Substraten nicht nur auf der der Spraydüse zugewandten Seite ermöglicht, sondern auch auf der abgeschatteten Rückseite. Dieses Verhalten wurde zur vollständigen ESI-Umhüllung von dichtgepackten Kohlenstoff-Faser-Bündeln mit haftvermittelnden Polymerschichten ausgenutzt. PY - 2011 DO - https://doi.org/10.1002/vipr.201100471 SN - 0947-076X SN - 1522-2454 VL - 23 IS - 6 SP - 17 EP - 23 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25392 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altmann, Korinna A1 - Schulze, Rolf-Dieter A1 - Hidde, Gundula A1 - Friedrich, Jörg-Florian T1 - Electrospray ionization for deposition of ultra-thin polymer layers – principle, electrophoretic effect and applications N2 - Nebulizing of polymer solutions, in a high-voltage field under atmospheric conditions by electrospray ionization (ESI), is a comfortable way to deposit ultra-thin layers of polar or ionic polymers onto any conductive substrate materials. The substrate is grounded and the polymer solution is sprayed through a powered capillary. The formed charged droplets shrink by solvent evaporation during their way to the grounded substrate, the charges close ranks and the droplets collapse consecutively by charge repulsion, thus forming finally charged single macromolecules. After their discharging at the grounded substrate, an ultrathin ‘quasi-monomolecular’ polymer layer is formed. It could be shown by imaging of scratches through the polymer layer by atomic force microscopy that the deposited polymer layers are dense at a thickness of about 10 nm. Carbon fibre bundles were coated with poly (allylamine) (PAAm) or poly(acrylic acid) (PAA) as potential adhesion-promoting layers in fibre–polymer composites. The polymer deposition is self-inhibiting after formation of a continuous coverage of about 200 nm for PAAm and 30 nm for PAA as result of surface charging. Continuous deposition onto such isolating layers or polymers without charging can be achieved by using current of alternating polarity. The film formation is self-healing because of the electrophoretic effect, i.e. the ion discharging occurs preferentially at noncoated areas. This electrophoretic effect of ESI was demonstrated by completely enwrapping all the carbon fibres of the roving within a distance of about 100 μm far from its outside and also at the backside of the fibre bundle with about 80% of the topside coverage, as measured by X-ray photoelectron spectroscopy and visualized using scanning electron microscopy. KW - Complete enwrapping of fibres KW - Ultra-thin polymer layers KW - Self-healing KW - Electrospray deposition KW - Carbon fibres KW - Electrophoretic effect PY - 2012 DO - https://doi.org/10.1080/01694243.2012.727170 SN - 0169-4243 VL - 27 IS - 9 SP - 988 EP - 1005 PB - Taylor & Francis CY - London AN - OPUS4-42631 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg A1 - Altmann, Korinna A1 - Wettmarshausen, Sascha A1 - Hidde, Gundula T1 - Coating of carbon fibers with adhesion-promoting thin polymer layers using plasma polymerization or electrospray ionization technique—A comparison N2 - Plasma polymers and electrospray-ionization (ESI) polymer layers are compared for most efficient adhesion promotion in carbon fiber-epoxy resin composites. The ultra-thin ESI layers (2–30 nm) of commercial poly(acrylic acid) and poly-(hydroxyethylmethacrylate) produce an significant increase of adhesion measured by single-fiber pull out tests. However, plasma Treatment has also advantages, such as simultaneous activation of the fiber substrate. Chemical structure and composition are rather far from the regular structure of commercial polymers as deposited by ESI processing. KW - Plasma polymers KW - Electrospray ionization polymers KW - Poly(acrylic acid) KW - Poly- (hydroxyethylmethacrylate) PY - 2017 DO - https://doi.org/10.1002/ppap.201600074 SN - 1612-8869 SN - 1612-8850 VL - 14 IS - 3 SP - e1600074-1 EP - 14 AN - OPUS4-40510 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wettmarshausen, Sascha A1 - Friedrich, Jörg Florian A1 - Meyer-Plath, Asmus A1 - Kalinka, Gerhard A1 - Hidde, Gundula A1 - Weidner, Steffen T1 - Coating of carbon fibers with adhesion-promoting thin poly(acrylic acid) and poly(hydroxyethylmethacrylate) layers using electrospray ionization N2 - Thin coatings of poly(acrylic acid) (PAA) and poly(hydroxyethylmethacrylate) (PHEMA) were deposited onto carbon fibers by means of the electrospray ionization (ESI) technique in ambient air. These high-molecular weight polymer layers were used as adhesion promoters in carbon fiber–epoxy resin composites. Within the ESI process, the carbon fibers were completely enwrapped with polymer in the upper 10 plies of a carbon fiber roving. As identified with scanning electron microscopy also shadowed fibers in a bundle as well as backsides of fiber rovings were pinhole-free coated with polymers (‘electrophoretic effect'). Under the conditions used, the layers have a granular structure. Residual solvent was absent in the deposit. PAA and PHEMA films did not show any changes in composition and structure in comparison with the original polymers as analyzed by X-ray photo-electron spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Single-fiber pullout tests of coated fibers embedded in epoxy resin showed significantly increased interfacial shear strength. It is assumed that chemical bonds between carbon fiber poly(acrylic acid) and epoxy resin contribute significantly to the improved interactions. KW - Adhesion promotion KW - Thin polymer layers KW - Electrospray ionization (ESI) KW - Carbon fiber–epoxy resin laminates KW - Layer topography PY - 2015 DO - https://doi.org/10.1080/01694243.2015.1040980 SN - 0169-4243 SN - 1568-5616 VL - 29 IS - 15 SP - 1628 EP - 1650 PB - VNU Science Press CY - Utrecht AN - OPUS4-34564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -