TY - JOUR A1 - Friedrich, Jörg Florian A1 - Geng, Sh. A1 - Unger, Wolfgang A1 - Lippitz, Andreas A1 - Erdmann, J. A1 - Gorsler, H.-V. T1 - Plasma functionalization and reorientation of macromolecules at polymer surfaces JF - Surface and coatings technology KW - Plasma KW - Polymer KW - Monolayer KW - Einschichtsystem KW - NEXAFS KW - Spektroskopie KW - Oberflächenanalyse PY - 1995 SN - 0257-8972 VL - 74-75 SP - 664 EP - 669 PB - Elsevier Science CY - Lausanne AN - OPUS4-627 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 JF - Plasma chemistry and plasma processing 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 - 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 JF - Plasma processes and polymers 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 - Friedrich, Jörg Florian A1 - Wigan, L. A1 - Unger, Wolfgang A1 - Lippitz, Andreas A1 - Erdmann, J. A1 - Gorsler, H.-V. T1 - Barrier properties of plasma and chemically fluorinated polypropylene and polyethyleneterephthalate JF - Surface and coatings technology N2 - The functionalization, perfluorination or an coating of polypropylene (PP) and polyethyleneterephthalate (PET) surfaces in different plasma atmospheres and in an F[2] + N[2] gas mixture were investigated. The aim of this work was to form a barrier layer against solvent and fuel permeation. Typical test solvents were n-pentane, toluene, tetrachloroethylene and mixtures of n-pentane and methanol. The permeation was gravimetrically measured. The permeation of the solvent mixtures was analyzed by mass spectrometry and Fourier transform IR spectroscopy. The permeation of the solvent mixtures through the plasma-modified polymer samples was associated with increased absorption of polar solvent components in the polymer film. The thickness of the plasma-fluorinated PP surface layer was 10-100 nm and that of chemically fluorinated PP about 5000 nm. Nearly the same barrier efficiency was measured for both plasma- and chemically fluorinated samples. T2 - International Conference on Plasma Surface Engineering No. 4 CY - Garmisch-Partenkirchen, Germany DA - 1994-09-19 KW - Plasma KW - Fluor KW - Plasmapolymer KW - Sperrschicht KW - Permeation PY - 1995 UR - http://cat.inist.fr/?aModele=afficheN&cpsidt=3158319 SN - 0257-8972 VL - 74-75 IS - 1-3 SP - 910 EP - 918 PB - Elsevier Science CY - Lausanne AN - OPUS4-628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gaft, M. A1 - Nagli, L. A1 - Gornushkin, Igor B. A1 - Groisman, Y. T1 - Doubly ionized ion emission in laser-induced breakdown spectroscopy in air JF - Analytical and bioanalytical chemistry N2 - The emission from doubly ionized species in laser-induced plasmas has not been properly investigated before since most analytical measurements were made at relatively long delays. This work proves that doubly ionized species, such as boron (B) III and iron (Fe) III, can exist during the first 150–200 ns of the plasma lifetime in plasmas produced in air by typical lasers with irradiances of 109 1011 W/cm². The emission from these ions was detected using both the double- and single-pulse excitations. The sum of the second ionization potential and the energy of corresponding excited states is approximately 30 eV. The presence of doubly charged ions in the early plasma was additionally confirmed by computer simulations using a collision-dominated plasma model. The Emission from doubly ionized species may be used for analytical purpose. For example, in the spectrum from a B–Fe ore, the B III analytical line at 206.6 nm is free from Fe spectral interference thus enabling the online laser-induced breakdown spectroscopy sorting of ores into three products with high, medium, and low B2O3 contents. KW - Plasma KW - Double ionization KW - Boron KW - Iron KW - Online KW - Sorting PY - 2011 DO - https://doi.org/10.1007/s00216-011-4847-0 SN - 1618-2642 SN - 1618-2650 VL - 400 IS - 10 SP - 3229 EP - 3237 PB - Springer CY - Berlin AN - OPUS4-25825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geng, Sh. A1 - Friedrich, Jörg Florian A1 - Gähde, J. A1 - Guo, L. T1 - Surface-Enhanced Infrared Absorption (SEIRA) and Its Use in analysis of Plasma-Modified Surface JF - Journal of applied polymer science KW - Plasma KW - IR KW - Surface-enhanced infrared absorption (SEIRA) KW - Surface modification PY - 1999 SN - 0021-8995 SN - 1097-4628 VL - 71 SP - 1231 EP - 1237 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-6985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gornushkin, Igor B. A1 - Shabanov, Sergej V. T1 - Geometrical effects in data collection and processing for calibration-free laser-induced breakdown spectroscopy JF - Journal of quantitative spectroscopy and radiative transfer N2 - Data processing in the calibration-free laser-induced breakdown spectroscopy (LIBS) is usually based on the solution of the radiative transfer equation along a particular line of sight through a plasma plume. The LIBS data processing is generalized to the case when the spectral data are collected from large portions of the plume. It is shown that by adjusting the optical depth and width of the lines the spectra obtained by collecting light from an entire spherical homogeneous plasma plume can be leastsquare fitted to a spectrum obtained by collecting the radiation just along a plume diameter with a relative error of 10−11 or smaller (for the optical depth not exceeding 0.3) so that a mismatch of geometries of data processing and data collection cannot be detected by fitting. Despite the existence of such a perfect least-square fit, the errors in the line optical depth and width found by a data processing with an inappropriate geometry can be large. It is shown with analytic and numerical examples that the corresponding relative errors in the found elemental number densities and concentrations may be as high as 50% and 20%, respectively. Safe for a few found exceptions, these errors are impossible to eliminate from LIBS data processing unless a proper solution of the radiative transfer equation corresponding to the ray tracing in the spectral data collection is used. KW - Plasma KW - LIBS KW - Plasma modeling PY - 2017 DO - https://doi.org/10.1016/j.jqsrt.2017.09.018 SN - 0022-4073 SN - 1879-1352 VL - 204 SP - 190 EP - 205 PB - Elsevier CY - New York, NY AN - OPUS4-42287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gornushkin, Igor B. A1 - Shabanov, Sergej V. T1 - Chemistry in laser‑induced plasmas at local thermodynamic equilibrium JF - Applied physics A N2 - The equation of state for plasmas containing negative and positive ions of elements and molecules formed by these elements is modeled under the assumption that all ionization processes and chemical reactions are at local thermal equilibrium and the Coulomb interaction in the plasma is described by the Debye–Hückel theory. The hierarchy problem for constants of molecular reactions is resolved by using three different algorithms for high, medium, and low temperatures: the contraction principle, the Newton–Raphson method, and a scaled Newton–Raphson method, respectively. These algorithms are shown to have overlapping temperature ranges in which they are stable. The latter allows one to use the developed method for calculating the equation of state in combination with numerical solvers of Navier–Stokes equations to simulate laser-induced Plasmas initiated in an atmosphere and to study formation of molecules and their ions in such plasmas. The method is applicable to a general chemical network. It is illustrated with examples of Ca–Cl and C–Si–N laser-induced plasmas. KW - Plasma KW - LIBS KW - Plasma modeling PY - 2018 DO - https://doi.org/10.1007/s00339-018-2129-9 SN - 1432-0630 SN - 0947-8396 VL - 124 IS - 10 SP - 716, 1 EP - 21 PB - Springer AN - OPUS4-46112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gross, Thomas A1 - Retzko, Iris A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang T1 - Time-of-flight-SIMS and XPS characterization of metal doped polymers JF - Applied surface science N2 - Organic thin films with defined chemical structures and physical properties are required for various applications. Plasma polymerization is of technological interest, since the deposition of plasma polymers is possible on any material of any shape in the desired thickness. We report on the TOF-SIMS (TOF: time-of-flight) and XPS investigations of pulse plasma ‘poly(acetylene)’ and alkali metal doped pulse plasma ‘poly(acetylene)’ films. The combination of TOF-SIMS and XPS supplies detailed information on the surface chemistry of these films. Application of both methods provides the possibility for cross-checking certain results. Moreover the different sensitivities of the methods can be utilized. According to the TOF-SIMS and XPS data it can be concluded that the interaction of alkali metals with plasma ‘poly(acetylene)’ results in electrovalent bonds of the type Me?+–C?- between carbon and metal. Furthermore carbon–oxygen–metal interactions were observed. These interactions are of the type C=O?-cdots, three dots, centeredMe?+ and/or C–O?-–Me?+. KW - SIMS KW - TOF-SIMS KW - XPS KW - Plasma KW - Polymer KW - Poly(acetylene) PY - 2003 DO - https://doi.org/10.1016/S0169-4332(02)00769-9 SN - 0169-4332 SN - 1873-5584 VL - 203-204 SP - 575 EP - 579 PB - North-Holland CY - Amsterdam AN - OPUS4-2271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grytsenko, K.P. A1 - Lytvyn, P. A1 - Friedrich, Jörg Florian A1 - Schulze, Rolf-Dieter A1 - Schrader, S. T1 - Influence of plasma discharge on the structure of polytetrafluoroethylene film and step coverage on polymer substrate JF - Materials science and engineering C N2 - Polytetrafluoroethylene (PTFE) films have been deposited onto polycarbonate (PC) substrates from the products of PTFE evaporation, activated by a cloud of accelerated electrons. A 40.68 MHz glow discharge was used during the deposition process. The polymer films have been characterised by XPS, FTIR and AFM. The use of the low power plasma during film growth led to the formation of PTFE films with modified structure. Films are amorphous and contain more cross-links, but in general, the structure of their macromolecules is still linear. An increase of RF-power leads to the formation of films with large amount of double bonds and enhanced internal stresses. Deposition of PTFE on PC without plasma treatment led to the formation of PTFE clusters up to 50 nm in diameter. The RMS roughness of the films, deposited without plasma, was about 4 nm, while the films deposited with plasma treatment had a roughness of 1.5 nm. The use of plasma has an additional effect if a PTFE coating is deposited on the PC substrate with submicrometer-sized steps. Without plasma the steps retain a rectangular shape. Deposited with the RF-discharge the PTFE layers resemble plasma-polymerised films. Under certain conditions the deposited films can fill trenches in the substrate like a wetting liquid, while under other conditions they avoid trenches and grow in between them. KW - Polytetrafluoroethylene KW - PTFE KW - Vacuum deposition KW - Plasma KW - Discharge KW - Film PY - 2007 DO - https://doi.org/10.1016/j.msec.2006.09.029 SN - 0928-4931 SN - 1873-0191 VL - 27 IS - 5-8 SP - 1227 EP - 1231 PB - Elsevier CY - Amsterdam AN - OPUS4-14014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -