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 - Dimitriev, O.P. A1 - Grytsenko, K.P. A1 - Lytvyn, P.M. A1 - Doroshenko, T.P. A1 - Briks, J.L. A1 - Tolmachev, A.I. A1 - Slominskii, Y.L. A1 - Kudinova, M.A. A1 - Schrader, S. A1 - Schulze, Rolf-Dieter A1 - Friedrich, Jörg Florian T1 - Substrate-induced self-assembly of donor-acceptor type compounds with terminal thiocarbonyl groups N2 - Two types of conjugated thiocarbonyl-terminated compounds have been synthesized and their ability to be adsorbed on surfaces of the different nature, namely, glass, polytetrafluoroethylene (PTFE), and gold has been studied. Different morphology of the films prepared by thermal vacuum evaporation and drop-casting from solutions has been observed depending on the surface used. It has been found that gold surface has a unique property to influence self-assembly of both monolayer and larger aggregates or crystals of the compounds, in contrast to glass and PTFE substrates. It was found that thiocarbonyl group is able to be chemisorbed to the gold surface. However, it was concluded that in spite of the fact that the thiocarbonyl groups are important for the chemical interaction with the gold surface, physical adsorption on the substrate surface, compound–compound and compound–solvent (when using solution) interactions are of great significance to drive self-assembly of the final film. KW - Thiocarbonyl group KW - Donor–acceptor compound KW - Gold surface KW - Aggregation KW - Film morphology PY - 2013 DO - https://doi.org/10.1016/j.tsf.2013.05.084 SN - 0040-6090 VL - 539 SP - 127 EP - 133 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-30571 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ramanujam, Maalolan A1 - Mix, Renate A1 - Wagner, M. A1 - Friedrich, Jörg Florian T1 - Effect of Br gassing after Ar plasma treatment of polyolefins N2 - For simulation and acceleration of artificial polymer ageing, polyolefin foils were exposed to low-pressure Ar plasma. Plasma particle bombardment and irradiation induce C–C and C–H bond scissions by σ→σ* excitations on the surface and in near-surface layers. Consequently, radicals are generated. They react by recombination, cross-linking, metastable trapping of the radical site or formation of olefinic double bonds. The long-living and metastable trapped C-radicals as well as double bonds in polyolefins were immediately exposed to bromine vapour without breaking the vacuum after switching-off the plasma. These reactive sites rapidly react with the molecular bromine under formation of C–Br bonds. For 5 min of argon plasma exposure, the elemental concentration of bromine was 13% for polyethylene and 22% Br/C for polypropylene as analysed by X-ray photoelectron spectroscopy. Nevertheless, not all C radical sites have reacted with bromine. Later on, when the polyolefins brought in contact with ambient air, an additional post-plasma reaction of the remaining trapped radicals with oxygen was observed. The oxygen concentrations were lower after bromine gassing, thus repressing partially the post-plasma oxidation in the analysed layer (ca. 6 nm) by radical quenching. Such bromination took place either at the surface or in near-surface layers because the Attenuated Total Reflectance (ATR)-FTIR spectra (sampling depth ca. 2500 nm) did not show significant changes for argon plasma-treated PE foils with and without bromine vapour exposure. Further addition of bromine may also occur on C=C double bonds. KW - Ageing of polyolefins KW - Argon plasma KW - Radical formation KW - Formation of double bonds PY - 2013 DO - https://doi.org/10.1080/01694243.2012.762326 SN - 0169-4243 SN - 1568-5616 VL - 27 IS - 6 SP - 1828 EP - 1839 PB - VNU Science Press CY - Utrecht AN - OPUS4-30572 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 - GEN A1 - Friedrich, Jörg Florian ED - Gutowski, W. ED - Dodiuk, H. T1 - Study of metal-polymer interfaces: Relevance to adhesion KW - Polymer surface modification KW - Adhesion KW - Spacer PY - 2013 SN - 978-90-04-20173-6 SN - 978-90-04-20174-3 SP - 3 EP - 33 PB - CRC Press AN - OPUS4-30576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heise, C. A1 - Schedler, U. A1 - Wettmarshausen, Sascha A1 - Friedrich, Jörg Florian T1 - Plasma-brominated cyclo-olefin polymer slides: Suiitable macroinitiators for activator regenerated by electron transfer/atom radical transfer polymerization N2 - Activators regenerated by electron transfer–atom radical transfer polymerization (ATRP) as a controlled living polymerization are distinguished by their acceptance of small amounts of transition-metal complexes and oxygen and by their tolerance of reducing agents at a high concentration. The precondition of all ATRP applications is the use of homolytic or heterolytic cleavable halides as a dormant species; this allows the propagation of monomer chains. Hence, alkyl bromides are slightly cleavable and are the preferred initiators for ATRP. The bromination of polymer slides used as macroinitiators was carried out under gentle bromoform plasma conditions. This led to an oxidation-resistant stable bromine layer. More than 20 bromines per 100 carbons on the polymer scaffold were permanently bound to the substrate after plasma treatment. The resulting amounts of secondary and tertiary bromines on the polymer scaffold exhibited a suitable macroinitiator concentration for the surface-initiated polymerization of methyl methacrylate and glycidyl methacrylate. KW - Copolymers KW - Functionalization of polymers KW - Grafting KW - Monolayers and polymer brushes KW - Radical polymerization PY - 2014 UR - http://onlinelibrary.wiley.com/doi/10.1002/app.40662/full DO - https://doi.org/10.1002/APP.40662 SN - 0021-8995 SN - 1097-4628 VL - 131 IS - 16 SP - 40662-1 EP - 40662-10 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-30577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Natte, Kishore A1 - Friedrich, Jörg Florian A1 - Wohlrab, Sebastian A1 - Lutzki, J. A1 - von Klitzing, R. A1 - Österle, Werner A1 - Orts-Gil, Guillermo T1 - Impact of polymer shell on the formation and time evolution of nanoparticle-protein corona N2 - The study of protein corona formation on nanoparticles (NPs) represents an actual main issue in colloidal, biomedical and toxicological sciences. However, little is known about the influence of polymer shells on the formation and time evolution of protein corona onto functionalized NPs. Therefore, silicapoly(ethylene glycol) core–shell nanohybrids (SNPs@PEG) with different polymer molecular weights (MW) were synthesized and exhaustively characterized. Bovine serum albumin (BSA) at different concentrations (0.1–6 wt%) was used as model protein to study protein corona formation and time evolution. For pristine SNPs and SNPs@PEG (MW = 350 g/mol), zeta potential at different incubation times show a dynamical evolution of the nanoparticle–protein corona. Oppositely, for SNPs@PEG with MW ≥2000 g/mol a significant suppression of corona formation and time evolution was observed. Furthermore, AFM investigations suggest a different orientation (side-chain or perpendicular) and Penetration depth of BSA toward PEGylated surfaces depending on the polymer length which may explain differences in protein corona evolution. KW - Nanoparticles KW - Silica KW - PEGylation KW - Protein corona KW - BSA KW - Biointerface PY - 2013 DO - https://doi.org/10.1016/j.colsurfb.2012.11.019 SN - 0927-7765 VL - 104 SP - 213 EP - 220 PB - Elsevier AN - OPUS4-38547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Natte, Kishore A1 - Österle, Werner A1 - Friedrich, Jörg Florian A1 - von Klitzing, R. A1 - Orts-Gil, Guillermo T1 - Tuning interfacial properties and colloidal behavior of hybrid nanoparticles by controlling the polymer precursor N2 - A facile and versatile synthetic route for controlling the size and surface potential of organic–inorganic hybrid silica nanoparticles (NPs) is introduced in this paper. For polymer-grafted NPs, the density of polymer chains on the surface is strongly affected by the concentration of precursor. Nevertheless, for condensed NPs, the precursor concentration determines the particle size but not the density of polymer chains on the surface or the adsorption of bovine serum albumin (BSA). Results presented here may have Major implications in biomedical and colloidal chemistry since interfacial and colloidal properties are known to drive several processes associated with nanoparticles in biological media. KW - BSA KW - Bio-interface KW - Nanosilica hybrids KW - PEG KW - Protein corona PY - 2012 DO - https://doi.org/10.1002/macp.201200148 SN - 0025-116X SN - 1022-1352 SN - 1521-3935 VL - 213 IS - 22 SP - 2412 EP - 2419 PB - Whiley-VCH CY - Weinheim AN - OPUS4-38549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zeynalov, Eldar A1 - Maherramova, S.N. A1 - Sadieva, N.F. A1 - Iskenderova, S.A. A1 - Agayev, B. K. A1 - Friedrich, Jörg Florian T1 - New softeners for polyvinylchloride N2 - Die Produktion von neuen effektiven und 'grünen' Weichmachern für Polyvinylchlorid (PVC) stellt eine der großen Herausforderungen in der chemischen Industrie dar. In diesem Beitrag wird über Ergebnisse von Untersuchungen berichtet, in denen symmetrische Ester einer Reihe von Fettsäuren und Triethylenglykol (TEG) gewonnen wurden und die als effektive Plastifizierungskomponenten verwendet wurden. Die Veresterung wurde unter Zugabe von Titandioxid Degussa P-25 in Nanopartikelgröße als umweltverträgliche Technologie durchgeführt. Eine gute Verträglichkeit und eine niedrige Flüchtigkeit der Ester auf Biobasis in den PVC-Rezepturen werden gezeigt und es konnten bessere physiko-mechanische Eigenschaften der PVC-Komposite eingestellt werden. Die Ester können als effektive und umweltfreundliche PVC-Weichmacher und als Ersatz für herkömmliche Phtalate empfohlen werden. N2 - Production of new types of effective and green softeners for polyvinylchloride (PVC) is one of the important concerns in chemical industry. The paper reports results of investigations on obtaining symmetric esters of a series of fatty acids and triethylene glycol (TEG) and their use as effective PVC plasticizing agents. The esterification process was conducted in the presence of nano-grade titanium dioxide Degussa P-25 and specified by environmentally sound technology. Good compatibility and low volatility of the bio-based type esters in PVC formulations were shown and higher physico-mechanical features of the PVC composites were established. The esters may be recommended as effective and environmentally friendly PVC softeners to replace commonly used phthalates. KW - Softener KW - Polyvinylchloride PY - 2012 SN - 0025-5300 VL - 54 IS - 4 SP - 246 EP - 248 PB - Hanser CY - München AN - OPUS4-25747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohamed, Zeinab A1 - Friedrich, Jörg Florian A1 - Krüger, Simone A1 - Farouk, M. A1 - Moustapha, M.E. T1 - Plasma deposition of adhesion-promoting polymer layers onto polypropylene for subsequent covering with thick fire retardant coatings N2 - Melamine resins were used as 50-µm-thick fire retardant coatings for polypropylene (PP). Preceding deposition, low-pressure plasma polymer films of allyl alcohol were coated onto PP to improve the adhesion between PP and melamine resin coatings. The efficiency of such fire retardant coatings was confirmed by flame tests. The plasma-deposited polymer and the dip-coated melamine resin films were characterized by Fourier transform infrared-attenuated total reflectance spectroscopy and X-ray photoelectron spectroscopy (XPS). The adhesion of coatings was measured using a 90° peel test with a doubled-faced adhesive tape. To detect the locus of failure, the peeled layer surfaces were inspected using optical microscopy and XPS. Thermal properties of PP thick melamine resin-coated films were analyzed by thermogravimetric analysis. KW - Polymer KW - Plasma KW - Polypropylene KW - Fire retardant KW - Melamine precursors KW - Plasma polymerization KW - Allyl alcohol KW - Flame retardants KW - Curing PY - 2015 DO - https://doi.org/10.1080/01694243.2015.1033878 SN - 0169-4243 SN - 1568-5616 VL - 29 IS - 14 SP - 1522 EP - 1533 PB - VNU Science Press CY - Utrecht AN - OPUS4-33112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohamed, Zeinab A1 - Friedrich, Jörg Florian A1 - Krüger, Simone T1 - Cured melamine systems as thick fire-retardant layers deposited by combination of plasma technology and dip-coating N2 - Melamine and melamine resins are widely used as fire-retardants for polymer building materials. Cured melamine systems are used in heat-sensitive items, such as furniture and window frames and sills. In this work, differently cured methylated poly(melamine-co-formaldehyde) (cmPMF) resins were used as fire-retardant coverage for poly(styrene) (PS) and poly(ethylene) (PE) building materials. Such polymer layers should have several tenths of micrometers thickness to produce sufficient fire retardancy. These thick layers were produced by dip-coating. To promote sufficient adhesion of such thick coating to the polyolefin substrates, also in the case of high temperatures occurring at fire exposure, the polymer substrates were firstly coated with a few hundred nanometer thick adhesion-promoting plasma polymer layer. Such thin plasma polymer layers were deposited by low-pressure plasma polymerization of allyl alcohol (ppAAl). It was assumed that the hydroxyl groups of ppAAl interact with the melamine resin; therefore, ppAAl was well suited as adhesion promoter for thick melamine resin coatings. Chemical structure and composition of polymer films were investigated using infrared-attenuated total reflectance and X-ray photoelectron spectroscopy (XPS). Peel strengths of coatings were measured. After peeling, the peeled polymer surfaces were also investigated using optical microscopy and XPS the layers for identification of the locus of peel front propagation. Thermal properties were analyzed using TGA (thermo-gravimetric analyses). Finally, the fire-retardant properties of such thick coated polymers were evaluated by exposure to flames. KW - Plasma polymerization KW - Dip-coating KW - Curing KW - Methylated poly(melamine-co-formaldehyde) KW - Polystyrene KW - Polyethylene KW - Flame retardancy KW - Polymer KW - Plasma KW - Melamine resin KW - Fire retardant PY - 2015 DO - https://doi.org/10.1080/01694243.2014.995911 SN - 0169-4243 SN - 1568-5616 VL - 29 IS - 9 SP - 807 EP - 820 PB - VNU Science Press CY - Utrecht AN - OPUS4-32795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohamed, Zeinab A1 - Friedrich, Jörg Florian A1 - Krüger, Simone T1 - Adhesion promotion of thick fire-retardant melamine polymer dip-coatings at polyolefin surfaces by using plasma polymers N2 - Melamine and melamine resins are widely used as fire retardants for polymer materials used in pharmaceutical, plastic, textile, rubber, and construction industry. Melamine-based flame retardants act by blowing off intumescent layers, char formation, and emission of quenching ammonia gas and diluent molecular nitrogen. Special advantages are: low cost, low smoke density and toxicity, low corrosive activity, safe handling, and environmental friendliness. Methylated poly(melamine-co-formaldehyde) (mPMF) was used as thick (≥40 µm) fire-retardant coating for plasma pretreated polymers. A combined low-pressure plasma pretreatment consisting of oxygen plasma exposure followed by deposition of thin poly(allylamine) (ppAAm) and poly(allyl alcohol) (ppAAl) plasma polymers as adhesion promoters have improved the adhesion of thick mPMF coatings strongly. Chemical structure and composition of deposited polymer films were characterized by infrared-attenuated total reflectance and X-ray photoelectron spectroscopy (XPS). After peeling, the peeled layer surfaces were also investigated for identification of the locus of failure and their topography using optical microscopy and XPS. Often the adhesion promotion was so efficient that the peeling of coating was not possible. Thermal properties of plasma polymers and dip-coating films were analyzed by thermogravimetric analysis. Significant improvement of fire-retardant properties of coated polymers was confirmed by flame tests. KW - Adhesion KW - Thick melamine layers KW - Plasma polymerization KW - Dip-coating KW - Methylated poly(melamine-co-formaldehyde) KW - Polystyrene KW - Polyethylene KW - Flame retardancy KW - Fire retardant KW - Melamine resin KW - Polymer KW - Plasma PY - 2014 DO - https://doi.org/10.1080/01694243.2014.943339 SN - 0169-4243 SN - 1568-5616 VL - 28 IS - 21 SP - 2113 EP - 2132 PB - VNU Science Press CY - Utrecht AN - OPUS4-31485 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mix, Renate A1 - Friedrich, Jörg Florian A1 - Neubert, Dietmar A1 - Inagaki, N. T1 - Response of linear, branched or crosslinked polyethylene structures on the attack of oxygen plasma N2 - Linear, branched and crosslinked polyethylenes (PE) were exposed to the low-pressure oxygen plasma for 2–120 s. In the following the samples were washed with solvents to remove low-molecular weight oxidized material and to excavate the subjacent polymer structure for microscopic characterization. X-ray photoelectron spectroscopy (XPS) measurements provided information about changes in elemental composition and chemical structure of PE after plasma exposure and washing. The calculation of the concentration of tertiary C atoms using XPS data was a measure of branches and crosslinking in the polymer before and after exposure to oxygen plasma. Linear PE was most sensitive towards oxygen plasma and showed the highest concentration in tertiary C atoms after plasma exposure. On the other hand branched PE types, which possess originally more tertiary carbon atoms, have lost two-third of them after 2 s oxygen plasma exposure. Branched PE show also topological changes at their surface as detected by atomic force microscopy. Differential scanning calorimetry measurements confirmed strong changes in crystallinity and molecular orientation of linear PE already after 120 s exposure to the oxygen plasma interpreted as amorphization. These effects should be interpreted as result of crosslinking caused by the recombination of dangling bond sites. KW - Linear and branched polyethylene KW - Oxygen plasma KW - Functionalization KW - Crosslinking PY - 2014 UR - http://link.springer.com/article/10.1007%2Fs11090-014-9558-9/fulltext.html DO - https://doi.org/10.1007/s11090-014-9558-9 SN - 0272-4324 VL - 34 IS - 5 SP - 1199 EP - 1218 PB - Plenum Publ. Corp. CY - New York, NY, USA AN - OPUS4-30741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Mix, Renate A1 - Yin, Huajie A1 - Friedrich, Jörg Florian ED - Gutowski, W. ED - Dodiuk, H. T1 - Aerosol-based DBD - A simple way to provide polymers with functional groups for adhesion promotion N2 - Polypropylene (PP) foils were exposed to the plasma of an atmospheric dielectric barrier discharge (DBD) in presence of different aerosols. Pure liquids such as water, ethanol, and 1/1 mixtures ethanol/water (v/v) or aqueous Solutions of acetic acid, poly(acrylic acid), poly(vinyl alcohol), and ethylene glycolpoly(vinyl alcohol) copolymer were introduced into the DBD. Surface composition, the number of functional groups per 100 C atoms, and water contact angles were correlated with the energy density of DBD plasma exposure. The wettability of the treated surfaces was investigated for different storage times. Peel strength of the thermally deposited aluminum layer to modified polymer surfaces revealed that the aerosol introduction strongly improves the adhesion between aluminum and polypropylene. KW - Aerosol-assisted DBD KW - Functional groups KW - Surface modification PY - 2013 SN - 978-90-04-20173-6 SN - 978-90-04-20174-3 SP - Chapter 8, 155 EP - 170 PB - CRC Press AN - OPUS4-30035 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 - CONF A1 - Mix, Renate A1 - Friedrich, Jörg Florian T1 - Adhesion promotion in metal-polymer composites by introduction of functional groups arranged in a well-defined distance to the polymer surface by spacer incorporation T2 - 10th International Conference on the Science and Technology of Adhesion and Adhesives, Euradh 2008 - Adhesion `08 CY - Oxford, UK DA - 2008-09-03 KW - Adhesion KW - Aluminium KW - Polypropylene KW - Plasma polymers KW - Spacer-bonded functional groups PY - 2008 SP - 447 EP - 451 PB - IOM Communications CY - London AN - OPUS4-18616 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Mix, Renate A1 - Wettmarshausen, Sascha T1 - A new concept for adhesion promotion in metal-polymer systems by introduction of covalently bonded spacers at the interface N2 - A new concept for molecular interface design in metal-polymer systems is presented. The main features of this concept are the replacement of weak physical interactions by strong covalent bonds, the flexibilization of the interface for compensating different thermal expansions of materials by using long-chain flexible and covalently bonded spacers between the metal and the polymer as well as its design as a moisture-repellent structure for hindering diffusion of water molecules into the interface and hydrolysis of chemical bonds. For this purpose, the main task was to develop plasmachemical and chemical techniques for equipping polymer surfaces with monotype functional groups of adjustable concentration. The establishing of monotype functional groups allows grafting the functional groups by spacer molecules by applying usual wet-chemical reactions. Four processes were favoured for production of monotype functional groups by highly selective reactions: the plasma bromination, the plasma deposition of plasma polymers, the post-plasma chemical reduction of O-functionalities to OH-groups, and the chemical replacement of bromine groups by NH2-groups. The grafting of flexible organic molecules as spacers between the metal layer and polymer improved the peel strength of the metal. To obtain maximal peel strength of aluminium coatings to polypropylene films and occurrence of cohesive failure in the polypropylene substrate, about 27 OH groups per 100 C-atoms or 6 COOH groups per 100 C-atoms were needed. Introducing C6-11-aliphatic spacers 1 OH or COOH group per 100 C-atoms contributed about 60% of the maximal peel strength of the Al-PP system, i.e. 2 or 3 spacer molecules per 100 C-atoms were sufficient for maximal peel strength. KW - Polymer surface functionalization KW - Spacer grafting KW - Metal-polymer adhesion PY - 2008 DO - https://doi.org/10.1163/156856108X309611 SN - 0169-4243 SN - 1568-5616 VL - 22 IS - 10-11 SP - 1123 EP - 1143 PB - VNU Science Press CY - Utrecht AN - OPUS4-17741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Mix, Renate A1 - Schulze, Rolf-Dieter A1 - Meyer-Plath, Asmus A1 - Joshi, Ranjit A1 - Wettmarshausen, Sascha T1 - New Plasma Techniques for Polymer Surface Modification with Monotype Functional Groups N2 - The production of chemically-defined plasma polymers and the introduction of monotype functional groups onto polymer surfaces are described. One method is to lower the energetic level of low-pressure plasmas. Pressure- and plasma-pulsed plasmas were successfully tested for the production of chemically-defined plasma polymers by increasing the monomer supply during the plasma-off period. Well-defined ultra-thin polymer films with regular structure were deposited from atmospheric plasmas by electrospray techniques. Post-plasma wet-chemical processing was also applied, as were gas/liquid-based aerosols and underwater plasmas. KW - Plasma KW - Polymer-Oberflächenfunktionalisierung KW - Macromolecular plasma KW - Monotype functional groups KW - Plasma bromination KW - Plasma treatment KW - Pressure-pulsed plasma KW - Underwater plasma PY - 2008 DO - https://doi.org/10.1002/ppap.200700145 SN - 1612-8850 SN - 1612-8869 VL - 5 IS - 5 SP - 407 EP - 423 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-17742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Joshi, Ranjit A1 - Friedrich, Jörg Florian A1 - Wagner, M.H. T1 - Study of carboxylic functionalization of polypropylene surface using the underwater plasma technique N2 - Non-equilibrium solution plasma treatment of polymer surfaces in water offers the possibility of more dense and selective polymer surface functionalization in comparison to the well-known and frequently used low-pressure oxygen plasma. Functional groups are introduced when the polymer surface contacts the plasma moderated solution especially water solutions. The emission of ions, electrons, energy-rich neutrals and complexes, produced by the ion avalanche are limited by quenching, with the aid of the ambient water phase. The UV-radiation produced in plasma formation also helps to moderate the reaction solution further by producing additional excited, ionized/dissociated molecules. Thus, monotype functional groups equipped polymer surfaces, preferably OH groups, originating from the dissociated water molecules, could be produced more selectively. An interesting feature of the technique is its flexibility to use a wide variety of additives in the water phase. Another way to modify polymer surfaces is the deposition of plasma polymers carrying functional groups as carboxylic groups used in this work. Acetic acid, acrylic acid, maleic and itaconic acid were used as additive monomers. Acetic acid is not a chemically polymerizing monomer but it could polymerize by monomer/molecular fragmentation and recombination to a cross linked layer. The other monomers form preferably water-soluble polymers on a chemical way. Only the fragmented fraction of these monomers could form an insoluble coating by cross linking to substrate. The XPS analysis was used to track the alterations in -O-CO- bond percentage on the PP surface. To identify the -COOH groups on substrate surface unambiguously, which have survived the plasma polymerization process, the derivatization with trifluoroethanol was performed. KW - Polymeroberflächen KW - Funktionelle Gruppen PY - 2009 DO - https://doi.org/10.1140/epjd/e2009-00088-6 SN - 1434-6060 VL - 54 IS - 2 SP - 249 EP - 258 PB - Springer CY - Berlin AN - OPUS4-19607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Mix, Renate A1 - Schulze, Rolf-Dieter A1 - Rau, A. T1 - Ultra-thin polymer layer deposition by aerosol-dielectric barrier discharge (DBD) and electrospray ionization (ESI) at atmospheric pressure N2 - Polyolefins are chemically inert and do not adhere well to metals, polymers or inorganics. To overcome this problem, polyolefin surfaces were modified thermally, plasmachemically, or by flame treatment with different oxygen-containing groups, however, unfortunately, such treatments were accompanied by undesired, adhesion lowering polymer degradation. To solve this dilemma, solutions of synthetic polymers and copolymers were prepared, sprayed into the barrier discharge or electrosprayed without discharge and deposited as thin adhesion-promoting layers. The deposited polymer layers from poly(vinylamine), poly(ethylene glycol)-poly(vinyl alcohol) copolymers and poly(acrylic acid) were endowed with monotype functional groups. Using the aerosol - dielectric barrier discharge only a fraction of functional groups survived the deposition process in contrast to the electrospray in which all functional groups were retained. KW - Polymer surface modification KW - Dielectric barrier discharge KW - Polymer aerosols KW - Electrospray deposition KW - Adhesion-promoting layers PY - 2010 DO - https://doi.org/10.1163/016942409X12598231568429 SN - 0169-4243 SN - 1568-5616 VL - 24 IS - 7 SP - 1329 EP - 1350 PB - VNU Science Press CY - Utrecht AN - OPUS4-21374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wettmarshausen, Sascha A1 - Mix, Renate A1 - Meyer-Plath, Asmus A1 - Mittmann, Hans-Ulrich A1 - Friedrich, Jörg Florian ED - K.L. Mittal, T1 - Plasma Bromination - a selective way to monotype functionalized polymer surfaces KW - Functional groups KW - Polymer surfaces KW - Plasma bromination KW - Grafting KW - Spacer KW - Selective plasma process PY - 2009 SN - 978-90-04-16590-8 VL - 5 SP - 3 EP - 18 PB - Koninklijke Brill NV CY - Leiden, The Netherlands AN - OPUS4-18944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Joshi, Ranjit A1 - Schulze, Rolf-Dieter A1 - Meyer-Plath, Asmus A1 - Friedrich, Jörg Florian T1 - Selective surface modification of Poly(propylene) with OH and COOH groups using liquid-plasma systems N2 - Underwater plasma and glow discharge electrolysis are interesting new methods for polymer surface functionalization. The achievable content of O-containing functional groups exceeds that of oxygen glow discharge gas plasmas by a factor of two (up to ca. 56 O/100 C). The percentage of OH groups among all O-containing groups can reach 25 to 40%, whereas it is about 10% in the gas plasmas. Addition of hydrogen peroxide increases the fraction of OH groups to at most 70% (27 OH/100 C). The liquid plasma systems are also able to polymerize acrylic acid and deposit the polymer as very thin film on substrate surfaces or membranes, thereby retaining about 80% of all COOH functional groups (27 COOH/100 C). KW - Polymeroberflächen KW - Funktionelle Gruppen PY - 2008 DO - https://doi.org/10.1002/ppap.200700175 SN - 1612-8850 SN - 1612-8869 VL - 5 IS - 7 SP - 695 EP - 707 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18884 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Friedrich, Jörg Florian T1 - Monosort functionalization of polymer surface as anchoring points for graft syntheses T2 - The Eleventh International Conference on Plasma Surface Engineering, PSE CY - Garmisch-Partenkirchen, Germany DA - 2009-09-15 PY - 2009 AN - OPUS4-18975 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -