TY - JOUR A1 - Fahmy, A. A1 - Mix, Renate A1 - Schönhals, Andreas A1 - Friedrich, Jörg Florian T1 - Surface and bulk structure of thin spin coated and plasma-polymerized polystyrene films N2 - Polystyrene (PS) spin coated thin films were modified by O2 and Ar plasma as well as by UV irradiation treatments. The modified PS samples were compared with plasma polymerized and commercial polystyrene. The effects of plasma (O2 and Ar) and UV irradiation treatments on the surface and the bulk properties of the polymer layers were discussed. The surface properties were evaluated by X-ray Photoelectron Spectroscopy and Contact angle measurements and the bulk properties were investigated by FTIR and dielectric relaxation spectroscopy. As a result only one second treatment time was sufficient to modify the surface. However, this study was also dedicated to understand the effect of plasma and plasma irradiation on the deposited layers of plasma polymers. The dielectric measurements showed that the plasma deposited films were not thermally stable and underwent an undesired post-plasma chemical oxidation. KW - Surface and bulk characterization KW - Plasma polymerization KW - Polystyrene KW - Surface modification KW - Thermal stability KW - Plasma polymers PY - 2012 DO - https://doi.org/10.1007/s11090-012-9372-1 SN - 0272-4324 VL - 32 IS - 4 SP - 767 EP - 780 PB - Plenum Publ. Corp. CY - New York, NY, USA AN - OPUS4-26264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Unger, Wolfgang T1 - Formation of Plasma Polymer Layers with Functional Groups of Different Type and Density at Polymer Surfaces and their Interaction with Al Atoms N2 - Monotype functionalizations with different types of functional groups (OH, NH2, COOH) on polypropylene and poly(tetrafluoroethylene) surfaces were synthesized using pulsed plasma-initiated homo- or copolymerization of functional group-carrying monomers. The maximum concentrations of functional groups were 31 OH, 18 NH2 or 24 COOH groups per 100 C atoms using allyl alcohol, allylamine or acrylic acid respectively as the monomer. The measured peel strengths of aluminium deposits increased linearly with the concentration of functional groups. Near the maximum concentration of OH (>27 OH/100 C atoms) or at moderate concentrations of COOH groups (>10 COOH/100 C atoms), constant (maximum) peel strengths were measured due to the mechanical collapse of one component in the composite (cohesive failure). Interface failures in Al-PP composites were found with COOH, NH2 and OH groups and cohesive failures were seen when higher concentrations of COOH groups were applied (>10 COOH/100 C atoms). PY - 2004 DO - https://doi.org/10.1002/ppap.200400008 SN - 1612-8850 SN - 1612-8869 VL - 1 IS - 1 SP - 28 EP - 50 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-4707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Mix, Renate A1 - Kühn, Gerhard T1 - Adhesion of metals to plasma-induced functional groups at polymer surfaces N2 - The peel strength of aluminium to polypropylene and poly(tetrafluoroethylene) was determined in dependence on the type and the concentration of functional groups on the polymer surface. For this purpose the polymer surface was equipped with monotype functional groups. The first method to produce monotype functionalized surfaces was an introduction of O functional groups using an oxygen plasma treatment and converting these groups to OH groups applying a wet chemical reduction. In result of this two-step treatment the hydroxyl group concentration at the polymer surface could be increased from 3–4 to 10–14 OH groups/100 C atoms. The second method consists in the deposition of a 150 nm adhesion-promoting layer of plasmapolymers or copolymers onto the polymer surface using the pulsed plasma technique. For that purpose functional groups carrying monomers as allyl alcohol, allylamine and acrylic acid were used. Applying the plasma-initiated copolymerization and using neutral “monomers” like ethylene or butadiene the concentration of the functional groups was varied. A correlation of peel strength with the ability of forming chemical interactions between Al atoms and functional groups was found: COOH > OH >> NH2 > H(CH2–CH2). KW - Peel strength KW - Aluminium KW - Polypropylene KW - Poly(tetrafluoroethylene) KW - Pulsed plasma KW - Allyl alcohol KW - Allylamine KW - Acrylic acid KW - Plasma surface treatment KW - Adhesion PY - 2005 SN - 0257-8972 VL - 200 IS - 1-4 SP - 565 EP - 568 PB - Elsevier Science CY - Lausanne AN - OPUS4-10897 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 - Hoffmann, Katrin A1 - Mix, Renate A1 - Resch-Genger, Ute A1 - Friedrich, Jörg Florian T1 - Monitoring of Amino Functionalities on Plasma-Chemically Modified Polypropylene Supports with a Chromogenic and Fluorogenic Pyrylium Reporter N2 - A straightforward strategy toward the sensitive fluorometric detection of primary amino groups on plasma-chemically modified polypropylene supports is presented, exploiting the transformation of the sterically nonhindered pyrylium dye Py-1 into its pyridinium counterpart. The reaction-induced blue-shifted absorption and emission bands and an increased fluorescence quantum yield provide the basis for the spectroscopic distinction between covalently bound and free, that is, nonspecifically adsorbed label molecules. With this label, for the first time, plasma-chemically introduced amino functionalities could be monitored on the surface of a polymer film employing fluorescence spectroscopy and confocal laser scanning microscopy. KW - Fluorescence spectroscopy KW - Surface characterization KW - Covalent labeling KW - Plasma modification KW - Fluorescent label PY - 2007 UR - http://pubs.acs.org/cgi-bin/abstract.cgi/langd5/2007/23/i16/abs/la7004908.html SN - 0743-7463 SN - 1520-5827 VL - 23 IS - 16 SP - 8411 EP - 8416 PB - American Chemical Society CY - Washington, DC AN - OPUS4-15717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Mix, Renate A1 - Resch-Genger, Ute A1 - Friedrich, Jörg Florian T1 - Fluorescence Measurements on Functionalized Polymer Surfaces - Problems and Troubleshooting KW - Fluorescence spectroscopy KW - Polymer functionalization KW - Surface labeling KW - Pyrylium label PY - 2008 DO - https://doi.org/10.1196/annals.1430.015 SN - 0077-8923 SN - 1749-6632 SN - 0094-8500 VL - 1130 SP - 28 EP - 34 PB - New York Academy of Sciences CY - New York, NY AN - OPUS4-17567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fahmy, A. A1 - Mix, Renate A1 - Schönhals, Andreas A1 - Friedrich, Jörg Florian T1 - Structure of plasma-deposited copolymer films prepared from acrylic acid and styrene: Part II variation of the comonomer ratio N2 - Copolymers of acrylic acid and styrene (AA/S) were prepared by pulsed plasma deposition technique. Their structure–property relationships were studied in dependence on the comonomer ratio. Both, the regularity of the structure and the composition of the thin copolymer films were investigated by bulk-sensitive (dielectric spectroscopy, FTIR, and differential scanning calorimetry) as well as surface-sensitive methods such as X-ray photoelectron spectroscopy (XPS). For an unambiguous identification of the functionality of the deposited films the COOH groups were estimated by derivatization with trifluoroethanol and subsequent XPS measurement as well as by the quantitative analysis of the FTIR data. As a result, the concentration of COOH groups on the surface and in the bulk is increasing with the fraction of AA in precursor mixture in a non-monotonous way but similar to the dependence obtained by conventional free radical polymerization. KW - Acrylic acid-styrene copolymer KW - Bulk properties KW - Dielectric properties KW - Plasma polymerization KW - Surface functionalization PY - 2013 DO - https://doi.org/10.1002/ppap.201200110 SN - 1612-8850 SN - 1612-8869 VL - 10 IS - 9 SP - 750 EP - 760 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-29096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gross, Thomas A1 - Pippig, F. A1 - Merz, B. A1 - Merz, R. A1 - Vohrer, U. A1 - Mix, Renate A1 - Steffen, H. A1 - Bremser, Wolfram A1 - Unger, Wolfgang T1 - Determination of OH groups at plasma oxidised poly(propylene) by TFAA chemical derivatisation XPS: an inter-laboratory comparison N2 - A first inter-laboratory comparison was conducted to demonstrate and document the capability of interested laboratories to measure the fraction of C—OH species on a plasma oxidised poly(propylene) sample by using a chemical derivatisation XPS approach. This report presents the results from that inter-laboratory comparison and includes the data received for the measured values and their associated standard deviations of laboratory means, at a 95% confidence level. The measurements were guided by a protocol developed within the group before and summarised shortly in the paper. Standard deviations that may characterise the state-of-the-art for the nominally simple and rather often practised case of TFAA chemical derivatisation XPS of C—OH species on a plasma oxidised polyolefin surface are calculated following ISO 5725-2:1994. The main conclusion is that the associated degree of equivalence reached by the participating laboratories in this comparison is still low. Further research to improve chemical derivatisation XPS protocols is mandatory. KW - Chemical derivatisation KW - ESCA/XPS KW - Inter-laboratory comparison KW - Photoelectron spectroscopy (PES) KW - Poly(propylene) (PP) PY - 2010 DO - https://doi.org/10.1002/ppap.200900142 SN - 1612-8850 SN - 1612-8869 VL - 7 IS - 6 SP - 494 EP - 503 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-21678 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 - JOUR A1 - Kricheldorf, H.R. A1 - Mix, Renate A1 - Weidner, Steffen T1 - Poly(ester urethane)s derived from lactide, isosorbide, terephthalic acidm abd various diisocyanates N2 - Isosorbide-initiated oligomerizations of ʟ-lactide were preformed in bulk using SnCl2 as catalyst. The resulting telechelic OH-terminated oligoesters were in situ subjected to simultaneous polycondensation and polyaddition with mixtures of terephthaloyl chloride and diisocyanates. Most polymerizations were conducted with 4,4'-diisocyanatodiphenyl methane and 2,4-diisocyanato toluene. The consequences of excess diisocyanate and four different catalysts were studied. The isosorbide/lactide ratio and the terephthalic acid/diisocyanate ratio were varied. Number average molecular weights up to 15 kDa with polydispersities around 3–5 were obtained. Depending on the chemical structure of the copolyester and on the feed ratio, incorporation of urethane groups may reduce or enhance the glass-transition temperature, but the thermal stability decreases dramatically regardless of composition. KW - Cyclization KW - Isosorbide KW - Lactide KW - Polyaddition KW - Polycondensation KW - Polyesters KW - Polyurethanes PY - 2014 DO - https://doi.org/10.1002/pola.27069 SN - 0360-6376 SN - 0887-624X VL - 52 IS - 6 SP - 867 EP - 875 PB - Wiley CY - Hoboken, NJ AN - OPUS4-30299 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 - Labahn, Diana A1 - Mix, Renate A1 - Schönhals, Andreas T1 - Dielectric relaxation of ultrathin films of supported polysulfone N2 - The dynamic glass transition (α relaxation, structural relaxation) of ultrathin polysulfone films prepared between aluminum electrodes is investigated by dielectric relaxation spectroscopy. As a main result, it is found that the glass transition temperature Tg does not depend on the thickness of the polymeric layer down to a thickness of 10 nm. For thicknesses lower than 10 nm, an increase of Tg is observed. A more detailed analysis of the temperature dependence of the relaxation rates reveals that the Vogel temperature increases and the fragility decreases systematically with decreasing film thickness d. Further, the dielectric strength Δε decreases with decreasing d. This is discussed by the formation of a surface layer of adsorbed polysulfone segments having a reduced molecular mobility with regard to the time scale characteristic of the glassy dynamics of bulk polysulfone. Plotted versus inverse film thickness Δε decreases linearly with 1/d and becomes zero for an extrapolated length scale of 10 nm. From that it is concluded that the thickness of the adsorbed boundary layer is about 5 nm. Contact-angle measurements were carried out to confirm the strong interaction between aluminum and polysulfone. It is also shown that preparation details like annealing conditions strongly influence the glass transition of supported ultrathin films. KW - Adsorbed layers KW - Aluminium KW - Annealing KW - Contact angle KW - Dielectric relaxation KW - Electrodes KW - Glass transition KW - Polymer films KW - Thin films PY - 2009 DO - https://doi.org/10.1103/PhysRevE.79.011801 SN - 1539-3755 SN - 1063-651X VL - 79 IS - 1 SP - 011801-1 - 011801-9 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-19050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Wettmarshausen, Sascha A1 - Hanelt, Sven A1 - Mach, Reinhard A1 - Mix, Renate A1 - Zeynalov, Eldar A1 - Meyer-Plath, Asmus T1 - Plasma-chemical bromination of graphitic materials and its use for subsequent functionalization and grafting of organic molecules N2 - Plasma-chemical bromination has been shown to be well-suited for highly selective and efficient C–Br-functionalization of polyolefin surfaces and has now been applied to graphitic materials, including highly oriented pyrolytic graphite (HOPG), natural graphite, carbon nanotubes, and graphitized carbon fibres. In contrast to the radical substitution of hydrogen by bromine at hydrogen-terminated sp3-hybridized carbon, bromination of all-carbon bound sp2-hybridized carbon in graphene requires addition to aromatic double bonds. The related change of sp2 to sp3 hybridization of the carbon atoms involved helps to explain experimental results of a loss in surface planarity on brominated HOPG. Bromine concentrations of up to 50 bromine atoms per 100 C-atoms were achieved in elemental bromine vapour under low-pressure plasma conditions using low-energetic inductively coupled radio-frequency plasma excitation. The time scale of the bromination progress was found to increase with the specific surface area of the material. The results of plasma-chemical bromination are compared to that of wet-chemical electrophilic addition reactions, which achieved 28 Br per 100 C for MWCNT. The resulting C–Br bonds from plasma-chemical processing of graphitic materials were shown to be well-suited for hydroxyl functionalization and for grafting of organic molecules by nucleophilic substitution with 1,6-diaminohexane and (3-aminopropyl)triethoxysilane. PY - 2010 DO - https://doi.org/10.1016/j.carbon.2010.06.054 SN - 0008-6223 SN - 1873-3891 VL - 48 IS - 13 SP - 3884 EP - 3894 PB - Pergamon Press CY - New York, NY AN - OPUS4-21954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yin, Huajie A1 - Mix, Renate A1 - Friedrich, Jörg Florian T1 - Influence of differently structured aluminium-polypropylene interfaces on adhesion N2 - Polar groups were introduced on polypropylene surfaces for increasing the surface energy and the peel strength to evaporated aluminium layers. Three kinds of plasma processes were used for introducing such functional groups to polyolefin surfaces: low-pressure radio-frequency (RF) O2 plasma exposure, atmospheric-pressure dielectric-barrier discharge (DBD) treatment in air, and the deposition of allylamine plasma polymer. The amino groups of the allylamine plasma polymer were also used as anchoring points for chemical introduction of covalently bonded spacer molecules equipped with reactive endgroups. Thus, silanol endgroups of a covalently bonded spacer were able to interact with the evaporated metal layer. The Al-PP composites achieved a maximal peel strength of 470 N/m by exposing the polymer to the lowpressure O2 plasma and 500 N/m on exposure to the atmospheric DBD plasma. After allylamine plasma polymerization and grafting of spacers, the peel strength was usually higher than 1500 N/m and the composites could not be peeled. KW - Polypropylene KW - Low-pressure RF oxygen plasma KW - Dielectric barrier discharge (DBD) KW - Pulsed plasma polymerization KW - Surface wettability KW - Peel strength PY - 2011 DO - https://doi.org/10.1163/016942410X511132 SN - 0169-4243 SN - 1568-5616 VL - 25 IS - 8 SP - 799 EP - 818 PB - VNU Science Press CY - Utrecht AN - OPUS4-23990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fahmy, A. A1 - Mix, Renate A1 - Schönhals, Andreas A1 - Friedrich, Jörg Florian T1 - Structure of plasma-deposited poly(acrylic acid) films N2 - Poly(acrylic acid) films with a thickness of about 150?nm were deposited using a pulsed plasma onto aluminum and glass. The structure/property relationships of these samples were studied in dependence to the duty cycle (DC) of the plasma by a broad combination of different techniques and probes. For the first time, volume sensitive methods (FTIR, dielectric spectroscopy, and differential scanning calorimetry) are combined with surface analyses i.e. XPS. For an unambiguous identification of COOH groups by XPS, derivatization with trifluoroethanol was accomplished. Quantitative FTIR investigations give qualitatively a dependence of the concentration of COOH groups upon DC similar to that given by XPS investigations. The observed differences are discussed considering the different analytical depths of both methods. The dielectric measurements reveal that the structure of the plasma deposited films is different from that of the bulk material. Moreover, these measurements show also that the plasma deposited films are not thermally stable but undergo a post plasma chemical reaction during heating, where the reaction kinetics depends on DC. PY - 2011 DO - https://doi.org/10.1002/ppap.201000108 SN - 1612-8850 SN - 1612-8869 VL - 8 IS - 2 SP - 147 EP - 159 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-23478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fahmy, A. A1 - Mix, Renate A1 - Schönhals, Andreas A1 - Friedrich, Jörg Florian T1 - Structure-property relationship of thin plasma deposited poly(allyl alcohol) films N2 - Poly(allyl alcohol) films with a thickness of about 150 nm were deposited by pulse plasma polymerization onto different substrates (inorganic and organic). The structure/property relationships of these samples were studied in dependence on the duty cycle (DC) of the plasma by a broad combination of different techniques and probes. For the first time volume sensitive methods (FTIR and dielectric spectroscopy) are combined with surface analytics by employing XPS for that system. FTIR spectroscopy gives qualitatively the same dependence of the concentration of the OH groups on DC like XPS. The observed differences are discussed considering the different analytical depths of both the methods. The dielectric measurements show that the plasma deposited films are not thermally stable but undergo a post plasma chemical reaction during heating. The results obtained by dielectric spectroscopy are discussed in detail with the data from FTIR and XPS measurements. KW - Allyl alcohol KW - Dielectric properties KW - Plasma polymerization KW - Surface and bulk characterization KW - Thermal stability PY - 2011 DO - https://doi.org/10.1007/s11090-011-9297-0 SN - 0272-4324 VL - 31 IS - 3 SP - 477 EP - 498 PB - Plenum Publ. Corp. CY - New York, NY, USA AN - OPUS4-23671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Mix, Renate A1 - Friedrich, Jörg Florian A1 - Buschmann, H.-J. A1 - Resch-Genger, Ute T1 - Anchoring of Fluorophores to plasma-chemically modified polymer surfaces and the effect of Cucurbit[6]uril on dye emission N2 - Polypropylene supports were functionalized by plasma-deposition of polymeric allylamine layers. The surface amino groups generated were wet-chemically reacted with xanthene dyes resulting in fluorescent polymer films. The effect of polymer-attachment of the dyes on their emission features was studied fluorometrically and different methods were tested to improve the fluorescence properties of the films. Modification with cucurbit[6]uril (CB6) yields a moderately enhanced fluorescence as well as an improved photostability. The observed effect is most likely due to CB6-induced rigidization of the linker molecules which seems to reduce fluorescence quenching dye–dye and fluorophore–surface interactions. KW - Fluorescence KW - Cucurbituril KW - Surface modification KW - Plasma functionalization KW - Polymer surface KW - Xanthene dyes PY - 2009 DO - https://doi.org/10.1007/s10895-008-0407-1 SN - 1053-0509 SN - 1573-4994 VL - 19 SP - 229 EP - 237 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-19154 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 - JOUR A1 - Girard-Lauriault, Pierre-Luc A1 - Retzko, Iris A1 - Swaraj, Sufal A1 - Matsubayashi, N. A1 - Gross, Thomas A1 - Mix, Renate A1 - Unger, Wolfgang T1 - Non-destructive sub-surface chemical characterization of air-exposed plasma polymers by energy-resolved XPS KW - Plasma polymers KW - Synchrotron XPS KW - Depth profiling KW - Derivatisation PY - 2010 DO - https://doi.org/10.1002/ppap.200900130 SN - 1612-8850 SN - 1612-8869 VL - 7 IS - 6 SP - 474 EP - 481 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-21711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baier, Jennifa A1 - Beck, Uwe A1 - Hidde, Gundula A1 - Hielscher, Stefan A1 - Lange, Thorid A1 - Mix, Renate T1 - Plasmagestützte Oberflächenfunktionalisierung von Polypropylen (PP) N2 - Polypropylen (PP) ist als Niedrigenergie-Polymer ohne nass- und plasmachemische Vorbehandlung weder haftfest zu beschichten noch verbundfest zu kleben. Typische Haft- bzw. Klebfestigkeiten liegen für die unbehandelte Polymeroberfläche bei maximal 0,5 MPa. Hinzu kommt, dass bei der Bestimmung von Haft- und Klebfestigkeiten der unmodifizierten Oberfläche mit großen Streuungen zu rechnen ist, die bezogen auf die Spannweite durchaus einem Faktor 5 entsprechen können. Generell besteht bei Prüfung der Haftfestigkeit mittels Stirnabzugsversuch und bei der Prüfung der Klebfestigkeit die Notwendigkeit eines statistisch validierten Herangehens. Hierzu sind zeitaufwändige Ein-Proben-Klebungen und -Prüfungen nur eingeschränkt geeignet. Zudem ist, insbesondere für geringe Haft- bzw. Klebfestigkeiten, ein querkraftfreies Prüfen Grundvoraussetzung. Im vorliegenden Beitrag werden verschiedenartige plasmagestützte Oberflächenfunktionalisierungen von PP sowie das Mehr-Proben-Konzept zur Klebung/Prüfung von bis zu acht Proben vorgestellt. Dazu werden ein BAM-Funktionsmuster einer Mehr-Proben-Kleb-Vorrichtung und eine kommerzielle analytische Zentrifuge zum Prüfen verwendet. T2 - 24. Workshop des Anwenderkreises Atmosphärendruckplasma "Haftung durch Oberflächenfunktionalisierung" CY - Erfurt, Germany DA - 11.11.2015 KW - Plasmamodifizierung KW - Polypropylen KW - Haftfestigkeit KW - Klebfestigkeit KW - Mehr-Proben-Kleben/-Prüfen PY - 2015 SP - 1 EP - 6 PB - Anwenderkreis Atmosphärendruckplasma CY - Jena AN - OPUS4-34838 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Friedrich, Jörg Florian T1 - Surface Controlled Fire Retardancy of Polymers Using Plasma Polymerisation N2 - Communication: Fire retardant coatings are deposited on polyamide-66 using plasma polymerisation. Chemical composition and thickness of deposits are adjusted varying the plasma treatment based on hexamethydisiloxane mixed with oxygen. The fire retardancy performances are evaluated using a cone calorimeter. The correlation between fire retardancy and thickness as well as chemical composition is discussed. KW - Cone calorimeter KW - Flame retardance KW - Heat release KW - Plasma polymerization KW - Polyamides PY - 2002 DO - https://doi.org/10.1002/1439-2054(20020901)287:9<579::AID-MAME579>3.0.CO;2-6 SN - 1438-7492 SN - 1439-2054 VL - 287 IS - 9 SP - 579 EP - 582 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-1537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mix, Renate A1 - Gerstung, Vanessa A1 - Falkenhagen, Jana A1 - Schulze, Rolf-Dieter A1 - Friedrich, Jörg Florian T1 - Characterization of plasma-polymerized allyl alcohol polymers and copolymers with styrene KW - Plasma polymerization KW - Surface functionalization KW - Molar mass PY - 2007 SN - 0169-4243 SN - 1568-5616 VL - 21 IS - 5-6 SP - 487 EP - 508 PB - VNU Science Press CY - Utrecht AN - OPUS4-14765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solomun, Tihomir A1 - Mix, Renate A1 - Sturm, Heinz T1 - Immobilization of silanized DNA on glass: influence of the silane tether on the DNA hybridization N2 - Two trifunctional (trimethoxy and triethoxy) and one difunctional (methyldimethoxy) 3-mercaptopropyl-alkoxysilanes were covalently tethered to thiolated DNA oligonucleotides in solution. After deposition as microarrays onto glass, the immobilized DNA probes were tested for hybridization ability by a florescence-based method. The results demonstrate a large enhancement in the fluorescence signal when the functionality of the silane tether is reduced from three to two. An XPS analyses revealed that this is not due to a higher DNA surface density. FTIR spectra of the spin-coated silanes showed that the trifunctional silanes form branched and cyclic siloxane moieties, whereas the difunctional silane generates predominantly short straight siloxane chains. Therefore, the propensity of trifunctional silanes to form more complex networks leads to conformations of the bound DNA which are less favorable for the specific interaction with the complementary strand. The data implicate that further significant improvements in the DNA hybridization ability are possible by adroit choice of the silane system. KW - Silanized DNA KW - DNA immobilization KW - DNA hybridization KW - Fluorescence imaging KW - FTIRS KW - XPS PY - 2010 DO - https://doi.org/10.1021/am100263t SN - 1944-8244 SN - 0013-936X SN - 1944-8252 VL - 2 IS - 8 SP - 2171 EP - 2174 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-22614 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solomun, Tihomir A1 - Schimanski, A. A1 - Sturm, Heinz A1 - Mix, Renate A1 - Illenberger, E. T1 - Surface Modification of Polyamides by Direct Fluorination N2 - Bulk samples and thin films of polyamides (PA6 and PA12) were exposed to fluorine (1 - 10 vol.-% F2 in N2) and analysed with photoelectron (XPS) and infrared spectroscopy. Fluorination affects both, the amide and the hydrocarbon parts of the polymers. However, only the carbon atom next to the carbonyl is readily fluorinated. Chemical modification of the amide group is apparent in a large binding energy shift (+5 eV) of the N1s level and the appearance of a CO band at 1734 cm-1. It is concluded that the amide C-N bond is cleaved in the fluorination process and that COOH and NF2 end groups are formed. This conclusion is corroborated by the appearance of ester oxygen in the XPS and by the 19F NMR spectra of the volatile products that show fluorine signals chemically shifted about 200 ppm towards lower field as compared with the CHF environment. KW - Gasfluorierung KW - IR KW - XPS KW - AFM KW - NF2-Gruppe PY - 2004 UR - http://www.e-polymers.org SN - 1618-7229 IS - 8 SP - 1 EP - 16 PB - De Gruyter CY - [S.l.] AN - OPUS4-3425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -