TY - INPR A1 - Bühler, Markus J. A1 - Rabu, Pierre A1 - Taubert, Andreas T1 - Advanced hybrid materials - design and applications T2 - European journal of inorganic chemistry : a journal of ChemPubSoc Europe Y1 - 2012 U6 - https://doi.org/10.1002/ejic.201201263 SN - 1434-1948 IS - 32 SP - 5092 EP - 5093 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Casse, Olivier A1 - Shkilnyy, Andriy A1 - Linders, Jürgen A1 - Mayer, Christian A1 - Häussinger, Daniel A1 - Völkel, Antje A1 - Thünemann, Andreas F. A1 - Dimova, Rumiana A1 - Cölfen, Helmut A1 - Meier, Wolfgang P. A1 - Schlaad, Helmut A1 - Taubert, Andreas T1 - Solution behavior of double-hydrophilic block copolymers in dilute aqueous solution JF - Macromolecules : a publication of the American Chemical Society N2 - The self-assembly of double-hydrophilic poly(ethylene oxide)-poly(2-methyl-2-oxazoline) diblock copolymers in water has been studied. Isothermal titration calorimetry, small-angle X-ray scattering, and analytical ultracentrifugation suggest that only single polymer chains are present in solution. In contrast, light scattering and transmission electron microscopy detect aggregates with radii of ca. 100 nm. Pulsed field gradient NMR spectroscopy confirms the presence of aggregates, although only 2% of the polymer chains undergo aggregation. Water uptake experiments indicate differences in the hydrophilicity of the two blocks, which is believed to be the origin of the unexpected aggregation behavior (in accordance with an earlier study by Ke et al. [Macromolecules 2009, 42, 5339-5344]). The data therefore suggest that even in double-hydrophilic block copolymers, differences in hydrophilicity are sufficient to drive polymer aggregation, a phenomenon that has largely been overlooked or ignored so far. Y1 - 2012 U6 - https://doi.org/10.1021/ma300621g SN - 0024-9297 VL - 45 IS - 11 SP - 4772 EP - 4777 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Delahaye, Emilie A1 - Goebel, Ronald A1 - Loebbicke, Ruben A1 - Guillot, Regis A1 - Sieber, Christoph A1 - Taubert, Andreas T1 - Silica ionogels for proton transport JF - Journal of materials chemistry N2 - A number of ionogels - silica-ionic liquid (IL) hybrid materials - were synthesized and studied for their ionic conductivity. The materials are based on a sulfonated IL, 1-methyl-3-(3-sulfopropyl-)-imidazolium p-toluenesulfonate, [PmimSO(3)H][PTS], which contains a sulfonic acid/sulfonate group both in the IL anion and in the side chain of the IL cation. By way of the sulfonate-sulfonic acid proton transfer, the IL imparts the ionogel with a high ionic conductivity of ca. 10(-2) S cm(-1) in the as-synthesized state at 120 degrees C and 10(-3) S cm(-1) in the dry state at 120 degrees C. The ionogels are stable up to ca. 150 degrees C in dynamic thermogravimetric analysis. This suggests that these materials, which are relatively cheap and easily fabricated, could find application in fuel cells in intermediate temperature ranges where many other membrane materials are not suitable. Y1 - 2012 U6 - https://doi.org/10.1039/c2jm00037g SN - 0959-9428 VL - 22 IS - 33 SP - 17140 EP - 17146 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Goebel, Ronald A1 - White, Robin J. A1 - Titirici, Maria-Magdalena A1 - Taubert, Andreas T1 - Carbon-based ionogels tuning the properties of the ionic liquid via carbon-ionic liquid interaction JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - The behavior of two ionic liquids (ILs), 1-ethyl-3-methylimidazolium dicyanamide [Emim][DCA] and 1-ethyl-3-methylimidazolium triflate [Emim][TfO], in (meso) porous carbonaceous hosts was investigated. Prior to IL incorporation into the host, the carbon matrix was thermally annealed between 180 and 900 degrees C to control carbon condensation and surface chemistry. The resulting materials have an increasing "graphitic'' carbon character with increasing treatment temperature, reflected in a modified behavior of the ILs when impregnated into the carbon host. The two ILs show significant changes in the thermal behavior as measured from differential scanning calorimetry; these changes can be assigned to anion-pi interaction between the IL anions and the pore wall surfaces of these flexible carbonaceous support materials. Y1 - 2012 U6 - https://doi.org/10.1039/c2cp23929a SN - 1463-9076 VL - 14 IS - 17 SP - 5992 EP - 5997 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Goebel, Ronald A1 - Xie, Zai-Lai A1 - Neumann, Mike A1 - Günter, Christina A1 - Loebbicke, Ruben A1 - Kubo, Shiori A1 - Titirici, Maria-Magdalena A1 - Giordano, Cristina A1 - Taubert, Andreas T1 - Synthesis of mesoporous carbon/iron carbide hybrids with unusually high surface areas from the ionic liquid precursor [Bmim][FeCl4] JF - CrystEngComm N2 - Mesoporous carbon/iron carbide hybrid materials with surface areas reaching 800 m(2) g(-1) were synthesized via an exotemplating route using monolithic mesoporous silica as template and the ionic liquid 1-butyl-3-methylimidazolium tetrachloridoferrate(III) [Bmim][FeCl4] as carbon and iron source. After heat treatment (750 degrees C under argon) of the [Bmim][FeCl4] precursor confined within the silica matrix, the silica exotemplate was removed with HF leaving the mesoporous C/Fe3C hybrid behind. The surface areas and the pore sizes depend on the exotemplate and the surface areas a significantly larger than any other surface area reported for C/Fe3C hybrid materials so far. The approach is thus a prototype for the synthesis of high-surface area iron carbide-based hybrid materials with potential application in catalysis. Y1 - 2012 U6 - https://doi.org/10.1039/c2ce25064k SN - 1466-8033 VL - 14 IS - 15 SP - 4946 EP - 4951 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Haase, A. A1 - Mantion, A. A1 - Graf, P. A1 - Plendl, J. A1 - Thünemann, Andreas F. A1 - Meier, Wolfgang P. A1 - Taubert, Andreas A1 - Luch, A. T1 - A novel type of silver nanoparticles and their advantages in toxicity testing in cell culture systems JF - Archives of toxicology : official journal of EUROTOX N2 - Silver nanoparticles (SNPs) are among the most commercialized nanoparticles worldwide. Often SNP are used because of their antibacterial properties. Besides that they possess unique optic and catalytic features, making them highly interesting for the creation of novel and advanced functional materials. Despite its widespread use only little data exist in terms of possible adverse effects of SNP on human health. Conventional synthesis routes usually yield products of varying quality and property. It thus may become puzzling to compare biological data from different studies due to the great variety in sizes, coatings or shapes of the particles applied. Here, we applied a novel synthesis approach to obtain SNP of well-defined colloidal and structural properties. Being stabilized by a covalently linked small peptide, these particles are nicely homogenous, with narrow size distribution, and form monodisperse suspensions in aqueous solutions. We applied these peptide-coated SNP in two different sizes of 20 or 40 nm (Ag20Pep and Ag40Pep) and analyzed responses of THP-1-derived human macrophages while being exposed against these particles. Gold nanoparticles of similar size and coating (Au20Pep) were used for comparison. The cytotoxicity of particles was assessed by WST-1 and LDH assays, and the uptake into the cells was confirmed via transmission electron microscopy. In summary, our data demonstrate that this novel type of SNP is well suited to serve as model system for nanoparticles to be tested in toxicological studies in vitro. KW - Silver nanoparticles KW - Peptide coating KW - Nanotoxicity Y1 - 2012 U6 - https://doi.org/10.1007/s00204-012-0836-0 SN - 0340-5761 VL - 86 IS - 7 SP - 1089 EP - 1098 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Haase, Andrea A1 - Rott, Stephanie A1 - Mantion, Alexandre A1 - Graf, Philipp A1 - Plendl, Johanna A1 - Thünemann, Andreas F. A1 - Meier, Wolfgang P. A1 - Taubert, Andreas A1 - Luch, Andreas A1 - Reiser, Georg T1 - Effects of silver nanoparticles on primary mixed neural cell cultures: Uptake, oxidative stress and acute calcium responses JF - Toxicological sciences N2 - In the body, nanoparticles can be systemically distributed and then may affect secondary target organs, such as the central nervous system (CNS). Putative adverse effects on the CNS are rarely investigated to date. Here, we used a mixed primary cell model consisting mainly of neurons and astrocytes and a minor proportion of oligodendrocytes to analyze the effects of well-characterized 20 and 40 nm silver nanoparticles (SNP). Similar gold nanoparticles served as control and proved inert for all endpoints tested. SNP induced a strong size-dependent cytotoxicity. Additionally, in the low concentration range (up to 10 mu g/ml of SNP), the further differentiated cultures were more sensitive to SNP treatment. For detailed studies, we used low/medium dose concentrations (up to 20 mu g/ml) and found strong oxidative stress responses. Reactive oxygen species (ROS) were detected along with the formation of protein carbonyls and the induction of heme oxygenase-1. We observed an acute calcium response, which clearly preceded oxidative stress responses. ROS formation was reduced by antioxidants, whereas the calcium response could not be alleviated by antioxidants. Finally, we looked into the responses of neurons and astrocytes separately. Astrocytes were much more vulnerable to SNP treatment compared with neurons. Consistently, SNP were mainly taken up by astrocytes and not by neurons. Immunofluorescence studies of mixed cell cultures indicated stronger effects on astrocyte morphology. Altogether, we can demonstrate strong effects of SNP associated with calcium dysregulation and ROS formation in primary neural cells, which were detectable already at moderate dosages. KW - silver nanoparticles KW - neurons KW - oxidative stress KW - protein carbonyls KW - calcium Y1 - 2012 U6 - https://doi.org/10.1093/toxsci/kfs003 SN - 1096-6080 VL - 126 IS - 2 SP - 457 EP - 468 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Neumann, Mike A1 - Noeske, Robert A1 - Taubert, Andreas A1 - Tiersch, Brigitte A1 - Strauch, Peter T1 - Highly structured, biomorphous beta-SiC with high specific surface area from Equisetaceae JF - Journal of materials chemistry N2 - Mesoporous, highly structured silicon carbide (beta-SiC) was synthesised from renewable plant materials (two Equisetaceae species) in a one-step carbothermal process at remarkably low temperatures down to 1200 degrees C. The SiC precursor is a silicon-carbon mixture with finely dispersed carbon prepared by pyrolysis of the organic plant matrix. Yields are 3 to 100% (omega(Si/Si) related to the silicon deposited in the plant material), depending on reaction temperature and time. IR spectroscopy, X-ray diffraction, and nitrogen sorption prove the formation of high-purity beta-SiC with minor inorganic impurities after purification and a high specific surface area of up to 660 m(2) g(-1). Scanning electron microscopy shows that the plant morphology is maintained in the final SiC. Sedimentation analysis finds a mean particle size (diameters d(50)) of 20 mu m. Y1 - 2012 U6 - https://doi.org/10.1039/c2jm30253e SN - 0959-9428 VL - 22 IS - 18 SP - 9046 EP - 9051 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Si, Satyabrata A1 - Taubert, Andreas A1 - Mantion, Alexandre A1 - Rogez, Guillaume A1 - Rabu, Pierre T1 - Peptide-intercalated layered metal hydroxides effect of peptide chain length and side chain functionality on structural, optical and magnetic properties JF - Chemical science N2 - New hybrid materials have been prepared by grafting synthetic peptides in the interlayer spacing of Cu(II) and Co(II) layered simple hydroxides (LSHs). The interlayer spacing of the hybrids depends on the peptide chain length; the dependence is specific for the copper and cobalt-based hybrids. This suggests a metal-or LSH-specific interaction of the peptides with the respective inorganic layers. When tyrosine is present in the peptide, its fluorescence is quenched after grafting the peptide to the LSH. Studies of the luminescence vs. pH indicate deprotonation of the tyrosine moieties to tyrosinate at high pH, accompanied by the onset of luminescence. The luminescence increases with increasing OH- concentration, suggesting an application of the hybrids as chemical sensors. Moreover, the peptides influence the magnetic properties of the hybrids. The copper-based hybrids behave antiferromagnetically and the cobalt-based hybrids are ferrimagnets. Y1 - 2012 U6 - https://doi.org/10.1039/c2sc01087a SN - 2041-6520 VL - 3 IS - 6 SP - 1945 EP - 1957 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Taubert, Andreas A1 - Stange, Franziska A1 - Li, Zhonghao A1 - Junginger, Mathias A1 - Günter, Christina A1 - Neumann, Mike A1 - Friedrich, Alwin T1 - CuO nanoparticles from the Strongly Hydrated Ionic Liquid Precursor (ILP) Tetrabutylammonium Hydroxide evaluation of the Ethanol Sensing Activity JF - ACS applied materials & interfaces N2 - The sensing potential of CuO nanoparticles synthesized via. precipitation from a water/ionic liquid precursor (ILP) mixture was investigated. The particles have a moderate surface area of 66 m(2)/g after synthesis, which decreases upon thermal treatment to below 5 m(2)/g. Transmission electron microscopy confirms crystal growth upon annealing, likely due to sintering effects. The as-synthesized particles can be used for ethanol sensing. The respective sensors show fast response and recovery times of below 10 s and responses greater than 2.3 at 100 ppm of ethanol at 200 degrees C, which is higher than any CuO-based ethanol sensor described so far. KW - ionic liquids KW - ionic liquid precursors KW - tetrabutylammonium hydroxide KW - nanoparticles KW - CuO KW - gas sensing Y1 - 2012 U6 - https://doi.org/10.1021/am201427q SN - 1944-8244 VL - 4 IS - 2 SP - 791 EP - 795 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Wang, Feipeng A1 - Lack, Alexander A1 - Xie, Zailai A1 - Frübing, Peter A1 - Taubert, Andreas A1 - Gerhard, Reimund T1 - Ionic-liquid-induced ferroelectric polarization in poly(vinylidene fluoride) thin films JF - Applied physics letters N2 - Thin films of ferroelectric beta-phase poly(vinylidene fluoride) (PVDF) were spin-coated from a solution that contained small amounts of the ionic liquid (IL) 1-ethyl-3-methylimidazolium nitrate. A remanent polarization of 60 mC/m(2) and a quasi-static pyroelectric coefficient of 19 mu C/m(2)K at 30 degrees C were observed in the films. It is suggested that the IL promotes the formation of the beta phase through dipolar interactions between PVDF chain-molecules and the IL. The dipolar interactions are identified as Coulomb attraction between hydrogen atoms in PVDF chains and anions in IL. The strong crystallinity increase is probably caused by the same dipolar interaction as well. KW - dielectric polarisation KW - ferroelectric thin films KW - polymer films KW - pyroelectricity KW - spin coating Y1 - 2012 U6 - https://doi.org/10.1063/1.3683526 SN - 0003-6951 VL - 100 IS - 6 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Xie, Zai-Lai A1 - Xu, Hai-Bing A1 - Gessner, Andre A1 - Kumke, Michael Uwe A1 - Priebe, Magdalena A1 - Fromm, Katharina M. A1 - Taubert, Andreas T1 - A transparent, flexible, ion conductive, and luminescent PMMA ionogel based on a Pt/Eu bimetallic complex and the ionic liquid [Bmim][N(Tf)(2)] JF - Journal of materials chemistry N2 - Transparent, ion-conducting, luminescent, and flexible ionogels based on the room temperature ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl) imide [Bmim][N(Tf)(2)], a PtEu2 chromophore, and poly(methylmethacrylate) (PMMA) have been prepared. The thermal stability of the PMMA significantly increases with IL incorporation. In particular, the onset weight loss observed at ca. 229 degrees C for pure PMMA increases to 305 degrees C with IL addition. The ionogel has a high ionic conductivity of 10(-3) S cm(-1) at 373 K and exhibits a strong emission in the red with a long average luminescence decay time of tau = 890 mu s. The resulting material is a new type of soft hybrid material featuring useful thermal, optical, and ion transport properties. Y1 - 2012 U6 - https://doi.org/10.1039/c2jm15862k SN - 0959-9428 VL - 22 IS - 16 SP - 8110 EP - 8116 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Ziolkowski, Bartosz A1 - Bleek, Katrin A1 - Twamley, Brendan A1 - Fraser, Kevin J. A1 - Byrne, Robert A1 - Diamond, Dermot A1 - Taubert, Andreas T1 - Magnetic ionogels (MagIGs) based on iron oxide nanoparticles, poly(N-isopropylacrylamide), and the ionic liquid trihexyl(tetradecyl)phosphonium dicyanamide JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - Magnetic ionogels (MagIGs) were prepared from organosilane-coated iron oxide nanoparticles, N-isopropylacrylamide, and the ionic liquid trihexyl(tetradecyl)phosphonium dicyanamide. The ionogels prepared with the silane-modified nanoparticles are more homogeneous than ionogels prepared with unmodified magnetite particles. The silane-modified particles are immobilized in the ionogel and are resistant tonanoparticle leaching. The modified particles also render the ionogels mechanically more stable than the ionogels synthesized with unmodified nanoparticles. The ionogels respond to external permanent magnets and are therefore prototypes of a new soft magnetic actuator. KW - Magnetic properties KW - Nanotechnology KW - Iron KW - Ionic liquids KW - Ionogels Y1 - 2012 U6 - https://doi.org/10.1002/ejic.201200597 SN - 1434-1948 IS - 32 SP - 5245 EP - 5251 PB - Wiley-VCH CY - Weinheim ER -