TY - GEN A1 - Lazareva, I. A1 - Koval, Yuri A1 - Müller, P. A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - Interface screening and imprint in pol(vinylidene fluoride/trifluoroethylene) ferroelectric field effect transistors KW - interface KW - screening KW - transistors Y1 - 2009 ER - TY - GEN A1 - Müller, Felix A1 - Torger, Bernhard A1 - Allertz, Peter J. A1 - Jähnichen, Klaus A1 - Keßler, Stefan A1 - Müller, Martin A1 - Simon, Frank A1 - Salchert, Katrin A1 - Mäurer, Haike A1 - Pospiech, Doris T1 - Multifunctional crosslinkable itaconic acid copolymers for enzyme immobilization T2 - European Polymer Journal N2 - UV-Crosslinkable itaconic copolymers are developed to provide new multifunctional materials for coatings which combine crosslinkable functionalities and the possibility to immobilize enzymes. The polymer-immobilized enzymes were used for water treatment to decompose persistent organic molecules. Introduction of suitable comonomers allows tailoring the mechanical and chemical properties for special applications. Copolymers containing MMA and itaconic anhydride were chosen because of the formation of long-term stable anhydride functionalities. These anhydride functionalities are employed to attach enzymes covalently. 4-Benzoylphenyl methacrylate is used as comonomer for UV-initiated crosslinking. Terpolymers are successfully obtained by radical copolymerization in solution. The copolymers are compared to poly(ethylene-alt-maleic anhydride) [P(EMA)] often used with respect to enzyme immobilization, activity and hydrolytic stability. The hydrolysis stability of the copolymers against water is studied by ATR-FTIR spectroscopy. Thin films are prepared on glass substrates in a layer-by-layer procedure by spin-coating. The layer formation is monitored by ATR-FTIR spectroscopy. UV-crosslinking of the copolymer films is performed taking the optimal irradiation dose that avoids polymer degradation. ATR-FTIR spectroscopy verifies the coupling reaction between amino groups of the enzyme and the anhydride groups on the surface of the crosslinked polymer film. The syringaldazine (4-hydroxy-3,5-dimethoxybenzaldehyde azine) test and 2,2´-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay demonstrate that the immobilized enzymes maintain their activities. The functional copolymers showed a significant effect in reduction of persistent organic pollutants in contaminated waste water. KW - ATR-FTIR spectroscopy KW - Crosslinking KW - Enzyme-immobilization KW - Itaconc acid KW - Methacrylate copolymer Y1 - 2018 U6 - https://doi.org/10.1016/j.eurpolymj.2018.03.014 VL - 102 SP - 47 EP - 55 ER - TY - GEN A1 - Koval, Yuri A1 - Lazareva, I. A1 - Müller, P. A1 - Müller, Klaus A1 - Henkel, Karsten A1 - Friedrich, Daniel T1 - Field effect transistors on graphitized polymer surfaces KW - transistors KW - polymer Y1 - 2011 ER - TY - CHAP A1 - Schmeißer, Dieter A1 - Müller, Sebastian A1 - Henkel, Karsten A1 - Müller, Klaus A1 - Wehner, Stefan T1 - In-situ analysis of moving reaction fronts for the bistable CO oxidation reaction on noble metal catalyst T2 - Extended Abstracts Book of First International Conference on Materials for Energy N2 - Experimental data on the reaction kinetics of catalytic processes are prerequisite for modeling of such reactions and their output. We investigate the CO oxidation on some noble metal catalysts, like Iridium(111) and Palladium(111) which is a bistable surface reaction. In a specific range of CO content in the feed gas islands of one or the other adsorbate nucleate and grow, which is recorded with photo electron emission microscopy (PEEM). During these transients the coverage on the surface changes from predominantly oxygen covered to predominantly CO covered resp. vice versa. But the resolution of PEEM and especially its unknown and nonlinear dependence of coverage of the two adsorbates (oxygen and CO) and image intensity make it impossible to extract the changes in coverage. On the other hand the reaction diffusion model based on the Langmuir-Hinshelwood-mechanism delivers the coverage of oxygen and carbon monoxide. The shapeand wall velocity of those islands has been connected perfectly to each other [CPL 423 (2006) 39], but not the absolute coverage and their variation during the reaction. Since the domain wall velocity is small on Iridium(111), this has opened the possibility for a detailed analysis of the changing coverage inside this domain wallutilizing synchrotron radiation and photo electron spectroscopy at BESSY II. The coverage profile of oxygen and CO inside a moving domain wall was measured for both cases using XPS spectra at O1s, C1s and the valence band during thereaction. Comparison with the reaction-diffusion-model and other catalytic surfaces, like Palladium(111) are done. KW - CO oxidation KW - Ir KW - Pd KW - photo electron emission microscopy (PEEM) Y1 - 2010 SN - 978-3-89746-117-8 SP - S. 932 PB - Dechema e.V. CY - Frankfurt ER - TY - GEN A1 - Henkel, Karsten A1 - Lazareva, I. A1 - Mandal, Dipankar A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Koval, Yuri A1 - Müller, P. A1 - Schmeißer, Dieter T1 - Electrical investigations on metal/ferroelectric/insulator/semiconductor structures using Poly[vinylidene fluoride trifluoroethylene] as ferroelectric layer for organic nonvolatile memory applications KW - metal KW - frerroelectric KW - insulator KW - semiconductor Y1 - 2009 ER - TY - CHAP A1 - Lazareva, I. A1 - Koval, Yuri A1 - Müller, P. A1 - Paloumpa, Ioanna A1 - Müller, Klaus A1 - Schmeißer, Dieter T1 - Field effect transistor of graphitized polyimide with P(VDF-TrFE) as gate insulator T2 - Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43 N2 - Surfaces of polyimide films were graphitized by low-energy ion irradiation. The conductivity was between 10−5 to 200 S/cm [1]. We prepared field effect transistors using this material. Ferroelectric P(VDF-TrFE) was used as gate insulator. The thickness of P(VDF-TrFE) varied from 120 nm to 1200 nm. Properties of P(VDF-TrFE) were investigated by current-voltage measurements of metal/ P(VDF-TrFE)/metal capacitors. We have found that at room temperature, the coercive field of P(VDF-TrFE) does not depend on the film thickness. At lower temperatures the coercive field increases proportionally to the reciprocal temperature. Remnant polarization is 9.5 µC/cm2. It slightly rises with decreasing temperature. Our recent results of field effect mobility, carrier concentration and threshold voltage are presented. [1] I. Lazareva, Y. Koval, M. Alam, S. Strömsdörfer, P. Müller, Appl. Phys. Lett. 90, 262108 (2007) Y1 - 2008 UR - http://www.dpg-verhandlungen.de/year/2008/conference/berlin/part/df/session/11/contribution/6 SN - 0420-0195 SP - S. 195 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER - TY - GEN A1 - Neyret, Margot A1 - Le Provost, Gaëtane A1 - Boesing, Andrea Larissa A1 - Schneider, Florian D. A1 - Baulechner, Dennis A1 - Bergmann, Joana A1 - Vries, Franciska T. de A1 - Fiore-Donno, Anna Maria A1 - Geisen, Stefan A1 - Goldmann, Kezia A1 - Merges, Anna A1 - Saifutdinov, Ruslan A. A1 - Simons, Nadja K. A1 - Tobias, Joseph A. A1 - Zaitsev, Andrey S. A1 - Gossner, Martin M. A1 - Jung, Kirsten A1 - Kandeler, Ellen A1 - Krauss, Jochen A1 - Penone, Caterina A1 - Schloter, Michael A1 - Schulz, Stefanie A1 - Staab, Michael A1 - Wolters, Volkmar A1 - Apostolakis, Antonios A1 - Birkhofer, Klaus A1 - Boch, Steffen A1 - Boeddinghaus, Runa S. A1 - Bolliger, Ralph A1 - Bonkowski, Michael A1 - Buscot, François A1 - Dumack, Kenneth A1 - Fischer, Markus A1 - Gan, Huei Ying A1 - Heinze, Johannes A1 - Hölzel, Norbert A1 - John, Katharina A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Marhan, Sven A1 - Müller, Jörg A1 - Renner, Swen C. A1 - Rillig, Matthias C. A1 - Schenk, Noëlle V. A1 - Schöning, Ingo A1 - Schrumpf, Marion A1 - Seibold, Sebastian A1 - Socher, Stephanie A. A1 - Solly, Emily F. A1 - Teuscher, Miriam A1 - Kleunen, Mark van A1 - Wubet, Tesfaye A1 - Manning, Peter T1 - A slow-fast trait continuum at the whole community level in relation to land-use intensification T2 - Nature Communications N2 - AbstractOrganismal functional strategies form a continuum from slow- to fast-growing organisms, in response to common drivers such as resource availability and disturbance. However, whether there is synchronisation of these strategies at the entire community level is unclear. Here, we combine trait data for 2800 above- and belowground taxa from 14 trophic guilds spanning a disturbance and resource availability gradient in German grasslands. The results indicate that most guilds consistently respond to these drivers through both direct and trophically mediated effects, resulting in a ‘slow-fast’ axis at the level of the entire community. Using 15 indicators of carbon and nutrient fluxes, biomass production and decomposition, we also show that fast trait communities are associated with faster rates of ecosystem functioning. These findings demonstrate that ‘slow’ and ‘fast’ strategies can be manifested at the level of whole communities, opening new avenues of ecosystem-level functional classification. KW - General Physics and Astronomy KW - General Biochemistry KW - General Chemistry KW - Multidisciplinary KW - Genetics and Molecular Biology Y1 - 2024 U6 - https://doi.org/10.1038/s41467-024-45113-5 SN - 2041-1723 VL - 15 IS - 1 ER - TY - GEN A1 - Boch, Steffen A1 - Allan, Eric A1 - Birkhofer, Klaus A1 - Bossdorf, Oliver A1 - Blüthgen, Nico A1 - Christ-Breulmann, Sabina A1 - Diekötter, Tim A1 - Dormann, Carsten F. A1 - Gossner, Martin M. A1 - Hallmann, Christine A1 - Hemp, Andreas A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klaus, Valentin H. A1 - Klein, Alexandra M. A1 - Kleinebecker, Till A1 - Lange, Markus A1 - Müller, Jörg A1 - Nacke, Heiko A1 - Prati, Daniel A1 - Renner, Swen C. A1 - Rothenwöhrer, Christoph A1 - Schall, Peter A1 - Schulze, Ernst-Detlef A1 - Socher, Stephanie A. A1 - Tscharntke, Teja A1 - Türke, Manfred A1 - Weiner, Christiane N. A1 - Weisser, Wolfgang W. A1 - Westphal, Catrin A1 - Wolters, Volkmar A1 - Wubet, Tesfaye A1 - Fischer, Markus T1 - Extensive und jährlich wechselnde Nutzungsintensität fördert den Artenreichtum im Grünland T2 - ANLIEGEN NATUR Y1 - 2016 UR - https://www.biom.uni-freiburg.de/mitarbeiter/dormann/boch2016anliegennatur.pdf SN - 1864-0729 VL - 38 IS - 1 SP - 86 EP - 95 ER - TY - GEN A1 - Müller, Klaus A1 - Paloumpa, Ioanna A1 - Henkel, Karsten A1 - Schmeißer, Dieter T1 - A polymer high-k dielectric insulator for organic field effect Transistors T2 - Journal of Applied Physics Y1 - 2005 SN - 0021-8979 VL - 98 IS - 5 SP - S. 056104 ER - TY - GEN A1 - Schmeißer, Dieter A1 - Henkel, Karsten A1 - Müller, Klaus A1 - Tallarida, Massimo T1 - Interface Reactions in Ultrathin Functional Dielectric Films KW - ultrathin KW - dielectric Y1 - 2009 ER -