TY - JOUR A1 - Haase, Andrea A1 - Arlinghaus, Heinrich F. A1 - Tentschert, Jutta A1 - Jungnickel, Harald A1 - Graf, Philipp A1 - Mantion, Alexandre A1 - Draude, Felix A1 - Galla, Sebastian A1 - Plendl, Johanna A1 - Goetz, Mario E. A1 - Masic, Admir A1 - Meier, Wolfgang P. A1 - Thuenemann, Andreas F. A1 - Taubert, Andreas A1 - Luch, Andreas T1 - Application of Laser Postionization Secondary Neutral Mass Spectrometry/Time-of-Flight Secondary Ion Mass Spectrometry in Nanotoxicology: Visualization of Nanosilver in Human Macrophages and Cellular Responses JF - ACS nano N2 - Silver nanoparticles (SNP) are the subject of worldwide commercialization because of their antimicrobial effects. Yet only little data on their mode of action exist. Further, only few techniques allow for visualization and quantification of unlabeled nanoparticles inside cells. To study SNP of different sizes and coatings within human macrophages, we introduce a novel laser postionization secondary neutral mass spectrometry (Laser-SNMS) approach and prove this method superior to the widely applied confocal Raman and transmission electron microscopy. With time-of-flight secondary ion mass spectrometry (TOF-SIMS) we further demonstrate characteristic fingerprints in the lipid pattern of the cellular membrane indicative of oxidative stress and membrane fluidity changes. Increases of protein carbonyl and heme oxygenase-1 levels in treated cells confirm the presence of oxidative stress biochemically. Intriguingly, affected phagocytosis reveals as highly sensitive end point of SNP-mediated adversity In macrophages. The cellular responses monitored are. hierarchically linked, but follow individual kinetics and are partially reversible. KW - nanosilver KW - Laser-SNMS KW - TOF-SIMS KW - confocal Raman microscopy KW - oxidative stress KW - protein carbonyls Y1 - 2011 U6 - https://doi.org/10.1021/nn200163w SN - 1936-0851 VL - 5 IS - 4 SP - 3059 EP - 3068 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Prieto, Susana A1 - Shkilnyy, Andriy A1 - Rumplasch, Claudia A1 - Ribeiro, Artur A1 - Javier Arias, F. A1 - Carlos Rodriguez-Cabello, Jose A1 - Taubert, Andreas T1 - Biomimetic calcium phosphate mineralization with multifunctional elastin-like recombinamers JF - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences N2 - Biomimetic hybrid materials based on a polymeric and an inorganic component such as calcium phosphate are potentially useful for bone repair. The current study reports on a new approach toward biomimetic hybrid materials using a set of recombinamers (recombinant protein materials obtained from a synthetic gene) as crystallization additive for calcium phosphate. The recombinamers contain elements from elastin, an elastic structural protein, and statherin, a salivary protein. Via genetic engineering, the basic elastin sequence was modified with the SN(A)15 domain of statherin, whose interaction with calcium phosphate is well-established. These new materials retain the biocompatibility, "smart" nature, and desired mechanical behavior of the elastin-like recombinamer (ELR) family. Mineralization in simulated body fluid (SBF) in the presence of these recombinamers reveals surprising differences. Two of the polymers inhibit calcium phosphate deposition (although they contain the statherin segment). In contrast, the third polymer, which has a triblock structure, efficiently controls the calcium phosphate formation, yielding spherical hydroxyapatite (HAP) nanoparticles with diameters from 1 to 3 nm after 1 week in SBF at 37 degrees C. However, at lower temperatures, no precipitation is observed with any of the polymers. The data thus suggest that the molecular design of ELRs containing statherin segments and the selection of an appropriate polymer structure are key parameters to obtain functional materials for the development of intelligent systems for hard tissue engineering and subsequent in vivo applications. Y1 - 2011 U6 - https://doi.org/10.1021/bm200287c SN - 1525-7797 VL - 12 IS - 5 SP - 1480 EP - 1486 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Farra, Ramzi A1 - Thiel, Kerstin A1 - Winter, Alette A1 - Klamroth, Tillmann A1 - Poeppl, Andreas A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Taubert, Andreas A1 - Strauch, Peter T1 - Tetrahalidocuprates(II)-structure and EPR spectroscopy Part 1: Tetrabromidocuprates(II) JF - New journal of chemistry N2 - Tetrahalidocuprates(II) show a high degree of structural flexibility. We present the results of crystallographic and electron paramagnetic resonance (EPR) spectroscopic analyses of four new tetrabromidocuprate(II) compounds and compare the results with previously reported data. The cations in the new compounds are the sterically demanding benzyltriphenylphosphonium, methyltriphenylphosphonium, tetraphenylphosphonium, and hexadecyltrimethylammonium ions; they were used to achieve a reasonable separation of the paramagnetic Cu(II) ions for EPR spectroscopy. X-Ray crystallography shows that in all four complexes the [CuBr4](2-) units have a distorted tetrahedral coordination geometry which is in agreement with DFT calculations. The EPR hyperfine structure was not resolved. This is due to the exchange broadening resulting from still incomplete separation of the paramagnetic Cu(II) centres. Nevertheless, the principal values of the electron Zeemann tensor (g(parallel to) and g(perpendicular to)) of the complexes could be determined. A correlation of structural (X-ray) parameters with the spin density at the copper centres (DFT) is well reflected in the EPR spectra of the bromidocuprates. This enables the correlation of X-ray and EPR parameters to predict the structure of tetrabromidocuprates in physical states other than the crystalline state. As a result, we provide a method to structurally characterize [CuBr4](2-) in, for example, ionic liquids or in solution, which has important implications for e.g. catalysis or materials science. Y1 - 2011 U6 - https://doi.org/10.1039/c1nj20271e SN - 1144-0546 VL - 35 IS - 12 SP - 2793 EP - 2803 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Graf, Philipp A1 - Mantion, Alexandre A1 - Haase, Andrea A1 - Thuenemann, Andreas F. A1 - Masic, Admir A1 - Meier, Wolfgang P. A1 - Luch, Andreas A1 - Taubert, Andreas T1 - Silicification of peptide-coated silver nanoparticles-A biomimetic soft chemistry approach toward chiral hybrid core-shell materials JF - ACS nano N2 - Silica and silver nanoparticles are relevant materials for new applications in optics, medicine, and analytical chemistry. We have previously reported the synthesis of pH responsive, peptide-templated, chiral silver nanoparticles. The current report shows that peptide-stabilized nanoparticles can easily be coated with a silica shell by exploiting the ability of the peptide coating to hydrolyze silica precursors such as TEOS or TMOS. The resulting silica layer protects the nanoparticles from chemical etching, allows their inclusion in other materials, and renders them biocompatible. Using electron and atomic force microscopy, we show that the silica shell thickness and the particle aggregation can be controlled simply by the reaction time. Small-angle X ray scattering confirms the Ag/peptide@silica core-shell structure. UV-vis and circular dichroism spectroscopy prove the conservation of the silver nanoparticle chirality upon silicification. Biological tests show that the biocompatibility in simple bacterial systems is significantly improved once a silica layer is deposited on the silver particles. KW - peptide-templated materials KW - silver nanoparticles KW - chiral nanoparticles KW - Ag/peptide@SiO(2) nanostructures KW - core-shell structures Y1 - 2011 U6 - https://doi.org/10.1021/nn102969p SN - 1936-0851 VL - 5 IS - 2 SP - 820 EP - 833 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Xie, Zai-Lai A1 - Taubert, Andreas T1 - Thermomorphic behavior of the ionic liquids [C(4)mim][FeCl4] and [C(12)mim][FeCl4] JF - ChemPhysChem : a European journal of chemical physics and physical chemistry N2 - The iron-containing ionic liquids 1-butyl-3-methylimidazolium tetrachloroferrate(III) [C(4)mim][FeCl4] and 1-dodecyl-3-methylimidazolium tetrachloroferrate(III) [C(12)mim][FeCl4] exhibit a thermally induced demixing with water (thermomorphism). The phase separation temperature varies with IL weight fraction in water and can be tuned between 100 degrees C and room temperature. The reversible lower critical solution temperature (LCST) is only observed at IL weight fractions below ca. 35% in water. UV/Vis, IR, and Raman spectroscopy along with elemental analysis prove that the yellow-brown liquid phase recovered after phase separation is the starting IL [C(4)mim][FeCl4] and [C(12)mim][FeCl4], respectively. Photometry and ICP-OES show that about 40% of iron remains in the water phase upon phase separation. Although the process is thus not very efficient at the moment, the current approach is the first example of an LCST behavior of a metal-containing IL and therefore, although still inefficient, a prototype for catalyst removal or metal extraction. KW - imidazolium KW - ionic liquids KW - phase transitions KW - Raman spectroscopy KW - thermomorphism Y1 - 2011 U6 - https://doi.org/10.1002/cphc.201000808 SN - 1439-4235 VL - 12 IS - 2 SP - 364 EP - 368 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Marquardt, Dorothea A1 - Xie, Zailai A1 - Taubert, Andreas A1 - Thomann, Ralf A1 - Janiak, Christoph T1 - Microwave synthesis and inherent stabilization of metal nanoparticles in 1-methyl-3-(3-carboxyethyl)-imidazolium tetrafluoroborate JF - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry N2 - The synthesis of Co-NPs and Mn-NPs by microwave-induced decomposition of the metal carbonyls Co-2(CO)(8) and Mn-2(CO)(10), respectively, yields smaller and better separated particles in the functionalized IL 1-methyl-3-(3-carboxyethyl)-imidazolium tetrafluoroborate [EmimCO(2)H][BF4] (1.6 +/- 0.3 nm and 4.3 +/- 1.0 nm, respectively) than in the non-functionalized IL 1-n-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4]. The particles are stable in the absence of capping ligands (surfactants) for more than six months although some variation in particle size could be observed by TEM. Y1 - 2011 U6 - https://doi.org/10.1039/c1dt10795j SN - 1477-9226 VL - 40 IS - 33 SP - 8290 EP - 8293 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Mantion, Alexandre A1 - Graf, Philipp A1 - Florea, Ileana A1 - Haase, Andrea A1 - Thuenemann, Andreas F. A1 - Masic, Admir A1 - Ersen, Ovidiu A1 - Rabu, Pierre A1 - Meier, Wolfgang P. A1 - Luch, Andreas A1 - Taubert, Andreas T1 - Biomimetic synthesis of chiral erbium-doped silver/peptide/silica core-shell nanoparticles (ESPN) JF - Nanoscale N2 - Peptide-modified silver nanoparticles have been coated with an erbium-doped silica layer using a method inspired by silica biomineralization. Electron microscopy and small-angle X-ray scattering confirm the presence of an Ag/peptide core and silica shell. The erbium is present as small Er(2)O(3) particles in and on the silica shell. Raman, IR, UV-Vis, and circular dichroism spectroscopies show that the peptide is still present after shell formation and the nanoparticles conserve a chiral plasmon resonance. Magnetic measurements find a paramagnetic behavior. In vitro tests using a macrophage cell line model show that the resulting multicomponent nanoparticles have a low toxicity for macrophages, even on partial dissolution of the silica shell. Y1 - 2011 U6 - https://doi.org/10.1039/c1nr10930h SN - 2040-3364 VL - 3 IS - 12 SP - 5168 EP - 5179 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Xie, Zai-Lai A1 - White, Robin J. A1 - Weber, Jens A1 - Taubert, Andreas A1 - Titirici, Magdalena M. T1 - Hierarchical porous carbonaceous materials via ionothermal carbonization of carbohydrates JF - Journal of materials chemistry N2 - We report on the ionothermal synthesis of porous carbon materials from a variety of carbohydrate precursors (i.e. D-glucose, D-fructose, D-xylose, and starch) using 1-butyl-3-methylimidazolium tetrachloroferrate(III), [Bmim][FeCl(4)] as a reusable solvent and catalyst. The carbon materials derived from these different carbohydrates are similar in terms of particle size and chemical composition, possessing relatively high surface areas from 44 to 155 m(2) g(-1) after ionothermal processing, which can be significantly increased to > 350 m(2) g(-1) by further thermal treatment (e. g. post-carbonization at 750 degrees C). CO(2) and N(2) sorption analysis, combined with Hg intrusion porosimetry, reveals a promising hierarchical pore structuring to these carbon materials. The ionic liquid [Bmim][FeCl(4)] has a triple role: it acts as both a soft template to generate the characterized pore structuring, solvent and as a catalyst resulting in enhanced ionothermal carbon yields. Importantly from a process point of view, the ionic liquid can be successfully recovered and reused. The current work shows that ionothermal synthesis has the potential to be an effective, low cost, and green reusable synthetic route towards sustainable porous carbon materials. Y1 - 2011 U6 - https://doi.org/10.1039/c1jm00013f SN - 0959-9428 VL - 21 IS - 20 SP - 7434 EP - 7442 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Thiel, Kerstin A1 - Klamroth, Tillmann A1 - Strauch, Peter A1 - Taubert, Andreas T1 - On the interaction of ascorbic acid and the tetrachlorocuprate ion [CuCl4](2-) in CuCl nanoplatelet formation from an ionic liquid precursor (ILP) JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - The formation of CuCl nanoplatelets from the ionic liquid precursor (ILP) butylpyridinium tetrachlorocuprate [C4Py](2)[CuCl4] using ascorbic acid as a reducing agent was investigated. In particular, electron paramagnetic resonance (EPR) spectroscopy was used to evaluate the interaction between ascorbic acid and the Cu(II) ion before reduction to Cu(I). EPR spectroscopy suggests that the [CuCl4](2-) ion in the neat IL is a distorted tetrahedron, consistent with DFT calculations. Addition of ascorbic acid leads to the removal of one chloride from the [CuCl4](2-) anion, as shown by DFT and the loss of symmetry by EPR. DFT furthermore suggests that the most stable adduct is formed when only one hydroxyl group of the ascorbic acid coordinates to the Cu(II) ion. Y1 - 2011 U6 - https://doi.org/10.1039/c1cp20648f SN - 1463-9076 VL - 13 IS - 30 SP - 13537 EP - 13543 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Löbbicke, Ruben A1 - Chanana, Munish A1 - Schlaad, Helmut A1 - Pilz-Allen, Christine A1 - Günter, Christina A1 - Möhwald, Helmuth A1 - Taubert, Andreas T1 - Polymer Brush Controlled Bioinspired Calcium Phosphate Mineralization and Bone Cell Growth JF - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences N2 - Polymer brushes on thiol-modified gold surfaces were synthesized by using terminal thiol groups for the surface initiated free radical polymerization of methacrylic acid and dimethylaminotheyl methacrylate, respectively. Atomic force microscopy shows that the resulting poly(methacrylic acid (PMAA) and poly(dimethylaminothyl methacrylate) (PDM- AEMA) brushes are homogeneous. Contact angle measurements show that the brushes are pH responsive and can reversibly be protonated and deprotonated. Mineralization of the brushes with calcium phosphate at different pH yields homogeneously mineralized surfaces, and preosteoblastic cells proliferate-on be number of living cells on the mineralized hybrid surface is ca. 3 times (P corresponding nonmineralized brushes. Y1 - 2011 U6 - https://doi.org/10.1021/bm200991b SN - 1525-7797 VL - 12 IS - 10 SP - 3753 EP - 3760 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Delahaye, Emilie A1 - Xie, Zailai A1 - Schäfer, Andreas A1 - Douce, Laurent A1 - Rogez, Guillaume A1 - Rabu, Pierre A1 - Günter, Christina A1 - Gutmann, Jochen S. A1 - Taubert, Andreas T1 - Intercalation synthesis of functional hybrid materials based on layered simple hydroxide hosts and ionic liquid guests - a pathway towards multifunctional ionogels without a silica matrix? JF - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry N2 - Functional hybrid materials on the basis of inorganic hosts and ionic liquids (ILs) as guests hold promise for a virtually unlimited number of applications. In particular, the interaction and the combination of properties of a defined inorganic matrix and a specific IL could lead to synergistic effects in property selection and tuning. Such hybrid materials, generally termed ionogels, are thus an emerging topic in hybrid materials research. The current article addresses some of the recent developments and focuses on the question why silica is currently the dominating matrix used for (inorganic) ionogel fabrication. In comparison to silica, matrix materials such as layered simple hydroxides, layered double hydroxides, clay-type substances, magnetic or catalytically active solids, and many other compounds could be much more interesting because they themselves may carry useful functionalities, which could also be exploited for multifunctional hybrid materials synthesis. The current article combines experimental results with some arguments as to how new, advanced functional hybrid materials can be generated and which obstacles will need to be overcome to successfully achieve the synthesis of a desired target material. Y1 - 2011 U6 - https://doi.org/10.1039/c1dt10841g SN - 1477-9226 VL - 40 IS - 39 SP - 9977 EP - 9988 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Shkilnyy, Andriy A1 - Schöne, Stefanie A1 - Rumplasch, Claudia A1 - Uhlmann, Annett A1 - Hedderich, Annett A1 - Günter, Christina A1 - Taubert, Andreas T1 - Calcium phosphate mineralization with linear poly(ethylene imine) a time-resolved study JF - Colloid and polymer science : official journal of the Kolloid-Gesellschaft N2 - We have earlier shown that linear poly(ethylene imine) (LPEI) is an efficient growth modifier for calcium phosphate mineralization from aqueous solution (Shkilnyy et al., Langmuir, 2008, 24 (5), 2102). The current study addresses the growth process and the reason why LPEI is such an effective additive. To that end, the solution pH and the calcium and phosphate concentrations were monitored vs. reaction time using potentiometric, complexometric, and photometric methods. The phase transformations in the precipitates and particle morphogenesis were analyzed by X-ray diffraction and transmission electron microscopy, respectively. All measurements reveal steep decreases of the pH, calcium, and phosphate concentrations along with a rapid precipitation of brushite nanoparticles early on in the reaction. Brushite transforms into hydroxyapatite (HAP) within the first 2 h, which is much faster than what is reported, for example, for calcium phosphate precipitated with poly(acrylic acid). We propose that poly(ethylene imine) acts as a proton acceptor (weak buffer), which accelerates the transformation from brushite to HAP by taking up the protons that are released from the calcium phosphate precipitate during the phase transformation. KW - Calcium phosphate KW - Polyethylene imine KW - Mineralization KW - Kinetics Y1 - 2011 U6 - https://doi.org/10.1007/s00396-011-2403-2 SN - 0303-402X VL - 289 IS - 8 SP - 881 EP - 888 PB - Springer CY - New York 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - Draude, F. A1 - Galla, S. A1 - Pelster, Axel A1 - Tentschert, J. A1 - Jungnickel, H. A1 - Haase, Alfred A1 - Mantion, Alexandre A1 - Thuenemann, Andreas F. A1 - Taubert, Andreas A1 - Luch, A. A1 - Arlinghaus, H. F. T1 - ToF-SIMS and Laser-SNMS analysis of macrophages after exposure to silver nanoparticles JF - Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films N2 - Silver nanoparticles (SNPs) are among the most commercialized nanoparticles because of their antibacterial effects. Besides being employed, e. g. as a coatingmaterial for sterile surfaces in household articles and appliances, the particles are also used in a broad range of medical applications. Their antibacterial properties make SNPs especially useful for wound disinfection or as a coating material for prostheses and surgical instruments. Because of their optical characteristics, the particles are of increasing interest in biodetection as well. Despite the widespread use of SNPs, there is little knowledge of their toxicity. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and laser post-ionization secondary neutral mass spectrometry (Laser-SNMS) were used to investigate the effects of SNPs on human macrophages derived from THP-1 cells in vitro. For this purpose, macrophages were exposed to SNPs. The SNP concentration ranges were chosen with regard to functional impairments of the macrophages. To optimize the analysis of the macrophages, a special silicon wafer sandwich preparation technique was employed; ToF-SIMS was employed to characterize fragments originating from macrophage cell membranes. With the use of this optimized sample preparation method, the SNP-exposed macrophages were analyzed with ToF-SIMS and with Laser-SNMS. With Laser-SNMS, the three-dimensional distribution of SNPs in cells could be readily detected with very high efficiency, sensitivity, and submicron lateral resolution. We found an accumulation of SNPs directly beneath the cell membrane in a nanoparticular state as well as agglomerations of SNPs inside the cells. KW - Laser-SNMS KW - ToF-SIMS KW - life sciences KW - imaging KW - nanoparticles KW - three-dimensional depth profiling Y1 - 2013 U6 - https://doi.org/10.1002/sia.4902 SN - 0142-2421 VL - 45 IS - 1 SP - 286 EP - 289 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Junginger, Mathias A1 - Kübel, Christian A1 - Schacher, Felix H. A1 - Müller, Axel H. E. A1 - Taubert, Andreas T1 - Crystal structure and chemical composition of biomimetric calcium phosphate nanofibers N2 - Calcium phosphate nanofibers with a diameter of only a few nanometers and a cotton-ball-like aggregate morphology have been reported several times in the literature. Although fiber formation seems reproducible in a variety of conditions, the crystal structure and chemical composition of the fibers have been elusive. Using scanning transmission electron microscopy, low dose electron (nano)diffraction, energy-dispersive X-ray spectroscopy, and energy- filtered transmission electron microscopy, we have assigned crystal structures and chemical compositions to the fibers. Moreover, we demonstrate that the mineralization process yields true polymer/calcium phosphate hybrid materials where the block copolymer template is closely associated with the calcium phosphate. Y1 - 2013 UR - http://pubs.rsc.org/en/content/articlepdf/2013/ra/c3ra23348k U6 - https://doi.org/10.1039/c3ra23348k ER - TY - JOUR A1 - Bagdahn, Christian A1 - Taubert, Andreas T1 - Ionogel fiber mats - functional materials via electrospinning of PMMA and the ionic liquid bis(1-butyl-3-methyl-imidazolium) Tetrachloridocuprate(II), [Bmim](2)[CuCl4] JF - Zeitschrift für Naturforschung : B, Chemical sciences N2 - Ionogel fiber mats were made by electrospinning poly(methylmethacrylate) (PMMA) and the ionic liquid (IL) bis(1-butyl-3-methyl-imidazolium) tetrachloridocupraten, [Bmim](2)[CuCl4], from acetone. The morphology of the electrospun ionogels strongly depends on the spinning parameters. Dense and uniform fiber mats were only obtained at concentrations of 60 to 70 g of polymer and IL mass combined. Lower concentrations led to a low number of poorly defined fibers. High voltages of 20 to 25 kV led to well-defined and uniform fibers; voltages between 15 and 20 kV again led to less uniform and less dense fibers. At 10 kV and lower, no spinning could be induced. Finally, PMMA fibers electrospun without IL show a less well-defined morphology combining fibers and oblong droplets indicating that the IL has a beneficial effect on the electrospinning process. The resulting materials are prototypes for new functional materials, for example in sterile filtration. KW - Ionic Liquid KW - Ionogel KW - Electrospinning KW - Fiber KW - Hydrogen Production KW - Filtration Y1 - 2013 U6 - https://doi.org/10.5560/ZNB.2013-3195 SN - 0932-0776 SN - 1865-7117 VL - 68 IS - 10 SP - 1163 EP - 1171 PB - De Gruyter CY - Tübingen ER - TY - JOUR A1 - Tentschert, J. A1 - Draude, F. A1 - Jungnickel, H. A1 - Haase, A. A1 - Mantion, Alexandre A1 - Galla, S. A1 - Thuenemann, Andreas F. A1 - Taubert, Andreas A1 - Luch, A. A1 - Arlinghaus, H. F. T1 - TOF-SIMS analysis of cell membrane changes in functional impaired human macrophages upon nanosilver treatment JF - Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films N2 - Silver nanoparticles (SNP) are among the most commercialized nanoparticles. Here, we show that peptide-coated SNP cause functional impairment of human macrophages. A dose-dependent inhibition of phagocytosis is observed after nanoparticle treatment, and pretreatment of cells with N-acetyl cysteine (NAC) can counteract the phagocytosis disturbances caused by SNP. Using the surface-sensitive mode of time-of-flight secondary ion mass spectrometry, in combination with multivariate statistical methods, we studied the composition of cell membranes in human macrophages upon exposure to SNP with and without NAC preconditioning. This method revealed characteristic changes in the lipid pattern of the cellular membrane outer leaflet in those cells challenged by SNP. Statistical analyses resulted in 19 characteristic ions, which can be used to distinguish between NAC pretreated and untreated macrophages. The present study discusses the assignments of surface cell membrane phospholipids for the identified ions and the resulting changes in the phospholipid pattern of treated cells. We conclude that the adverse effects in human macrophages caused by SNP can be partially reversed through NAC administration. Some alterations, however, remained. KW - silver nanoparticles KW - lipidomics KW - N-acetyl cysteine KW - phagocytosis KW - oxidative stress Y1 - 2013 U6 - https://doi.org/10.1002/sia.5155 SN - 0142-2421 VL - 45 IS - 1 SP - 483 EP - 485 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Junginger, Mathias A1 - Kübel, Christian A1 - Schacher, Felix H. A1 - Müller, Axel H. E. A1 - Taubert, Andreas T1 - Crystal structure and chemical composition of biomimetic calcium phosphate nanofibers JF - RSC Advances N2 - Calcium phosphate nanofibers with a diameter of only a few nanometers and a cotton-ball-like aggregate morphology have been reported several times in the literature. Although fiber formation seems reproducible in a variety of conditions, the crystal structure and chemical composition of the fibers have been elusive. Using scanning transmission electron microscopy, low dose electron (nano) diffraction, energy-dispersive X-ray spectroscopy, and energy-filtered transmission electron microscopy, we have assigned crystal structures and chemical compositions to the fibers. Moreover, we demonstrate that the mineralization process yields true polymer/calcium phosphate hybrid materials where the block copolymer template is closely associated with the calcium phosphate. Y1 - 2013 U6 - https://doi.org/10.1039/c3ra23348k SN - 2046-2069 VL - 3 IS - 28 SP - 11301 EP - 11308 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Unuabonah, Emmanuel Iyayi A1 - Günter, Christina A1 - Weber, Jens A1 - Lubahn, Susanne A1 - Taubert, Andreas T1 - Hybrid Clay - a new highly efficient adsorbent for water treatment JF - ACS sustainable chemistry & engineering N2 - New hybrid clay adsorbent based on kaolinite clay and Carica papaya seeds with improved cation exchange capacity (CEC), rate of heavy metal ion uptake, and adsorption capacity for heavy metal ions were prepared. The CEC of the new material is ca. 75 meq/100 g in spite of the unexpectedly low surface area (approximate to 19 m(2)/g). Accordingly, the average particle size of the hybrid clay adsorbent decreased from over 200 to 100 pm. The hybrid clay adsorbent is a highly efficient adsorbent for heavy metals. With an initial metal concentration of 1 mg/L, the hybrid clay adsorbent reduces the Cd2+, Ni2+, and Pb2+ concentration in aqueous solution to <= 4, <= 7 and <= 20 mu g/L, respectively, from the first minute to over 300 min using a fixed bed containing 2 g of adsorbent and a flow rate of approximate to 7 mL/min. These values are (with the exception of Pb2+) in line with the WHO permissible limits for heavy metal ions. In a cocktail solution of Cd2+, and Ni2+, the hybrid clay shows a reduced rate of uptake but an increased adsorption capacity. The CEC data suggest that the adsorption of Pb2+, Cd2+, and Ni2+ on the hybrid clay adsorbent is essentially due to ion exchange. This hybrid clay adsorbent is prepared from materials that are abundant and by a simple means that is sustainable, easily recovered from aqueous solution, nonbiodegradable (unlike numerous biosorbent), and easily regenerated and is a highly efficient alternative to activated carbon for water treatment. KW - Kaolinite KW - Hybrid clay KW - Water treatment KW - Cation exchange Capacity KW - Adsorbent KW - Kinetics Y1 - 2013 U6 - https://doi.org/10.1021/sc400051y SN - 2168-0485 VL - 1 IS - 8 SP - 966 EP - 973 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Unuabonah, Emmanuel Iyayi A1 - Olu-Owolabi, Bamidele I. A1 - Taubert, Andreas A1 - Omolehin, Elizabeth B. A1 - Adebowale, Kayode O. T1 - SAPK a novel composite resin for water treatment with very high Zn2+, Cd2+, and Pb2+ adsorption capacity JF - Industrial & engineering chemistry research N2 - A new sulfonated aniline-modified poly(vinyl alcohol)/K-feldspar (SAPK) composite was prepared. The cation-exchange capacity of the composite was found to be S times that of neat feldspar. The specific surface area and point of zero charge also changed significantly upon modification, from 15.6 +/- 0.1 m(2)/g and 2.20 (K-feldspar) to 73.6 +/- 0.3 m(2)/g and 1.91 (SAPK). Zn2+, Cd2+, and Pb2+ adsorption was found to be largely independent of pH, and the metal adsorption rate on SAPK was higher than that on neat feldspar. This particularly applies to the initial adsorption rates. The adsorption process involves both film and pore diffusion; film diffusion initially controls the adsorption. The Freundlich and Langmuir models were found to fit metal-ion adsorption on SAPK most accurately. Adsorption on neat feldspar was best fitted with a Langmuir model, indicating the formation of adsorbate monolayers. Both pure feldspar and SAPK showed better selectivity for Pb2+ than for Cd2+ or Zn2+. Y1 - 2013 U6 - https://doi.org/10.1021/ie3024577 SN - 0888-5885 VL - 52 IS - 2 SP - 578 EP - 585 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Xie, Zai-Lai A1 - Huang, Xing A1 - Titirici, Maria-Magdalena A1 - Taubert, Andreas T1 - Mesoporous graphite nanoflakes via ionothermal carbonization of fructose and their use in dye removal JF - RSC Advances N2 - The large-scale green synthesis of graphene-type two-dimensional materials is still challenging. Herein, we describe the ionothermal synthesis of carbon-based composites from fructose in the iron-containing ionic liquid 1-butyl-3-methylimidazolium tetrachloridoferrate(III), [Bmim][FeCl4] serving as solvent, catalyst, and template for product formation. The resulting composites consist of oligo-layer graphite nanoflakes and iron carbide particles. The mesoporosity, strong magnetic moment, and high specific surface area of the composites make them attractive for water purification with facile magnetic separation. Moreover, Fe3Cfree graphite can be obtained via acid etching, providing access to fairly large amounts of graphite material. The current approach is versatile and scalable, and thus opens the door to ionothermal synthesis towards the larger-scale synthesis of materials that are, although not made via a sustainable process, useful for water treatment such as the removal of organic molecules. Y1 - 2014 U6 - https://doi.org/10.1039/c4ra05146g SN - 2046-2069 VL - 4 IS - 70 SP - 37423 EP - 37430 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Xie, Zai-Lai A1 - Huang, Xing A1 - Taubert, Andreas T1 - DyeIonogels: proton-responsive ionogels based on a dye-ionic liquid exhibiting reversible color change JF - Advanced functional materials N2 - Transparent, ion-conducting, and flexible ionogels based on the room temperature ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl) imide [Bmim][N(Tf)(2)], the dye-IL (DIL) 1-butyl-3-methylimidazolium methyl orange [Bmim][MO], and poly(methylmethacrylate) (PMMA) are prepared. Upon IL incorporation the thermal stability of the PMMA matrix significantly increases from 220 to 280 degrees C. The ionogels have a relatively high ionic conductivity of 10(-4) S cm(-1) at 373 K. Most importantly, the ionogels exhibit a strong and reversible color change when exposed to aqueous or organic solutions containing protons or hydroxide ions. The resulting material is thus a prototype of soft multifunctional matter featuring ionic conductivity, easy processability, response to changes in the environment, and a strong readout signal, the color change, that could be used in optical data storage or environmental sensing. Y1 - 2014 U6 - https://doi.org/10.1002/adfm.201303016 SN - 1616-301X SN - 1616-3028 VL - 24 IS - 19 SP - 2837 EP - 2843 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Tentschert, Jutta A1 - Jungnickel, Harald A1 - Reichardt, Philipp A1 - Leube, Peter A1 - Kretzschmar, Bernd A1 - Taubert, Andreas A1 - Luch, A. T1 - Identification of nano clay in composite polymers JF - Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films N2 - Industrialized food production is in urgent search for alternative packaging materials, which can serve the requirements of a globalized world in terms of longer product shelf lives, reduced freight weight to decrease transport costs, and better barrier functionality to preserve its freshness. Polymer materials containing organically modified nano clay particles as additives are one example for a new generation of packaging materials with specific barrier functionality to actually hit the market. Clay types used for these applications are aluminosilicates, which belong to the mineral group of phyllosilicates. These consist of nano-scaled thin platelets, which are organically modified with quaternary ammonium compounds acting as spacers between the different clay layers, thereby increasing the hydrophobicity of the mineral additive. A variety of different organically modified clays are already available, and the use as additive for food packaging materials is one important application. To ensure valid risk assessments of emerging nano composite polymers used in the food packaging industry, exact analytical characterization of the organically modified clay within the polymer matrix is of paramount importance. Time-of-flight SIMS in combination with multivariate statistical analysis was used to differentiate modified clay reference materials from another. Time-of-flight SIMS spectra of a reference polymer plate, which contained one specific nano clay composite, were acquired. For each modified clay additive, a set of characteristic diagnostic ions could be identified, which then was used to successfully assign unknown clay additives to the corresponding reference material. Thus, the described methodology could be used to define and characterize nano clay within polymer matrices. Copyright (c) 2014 John Wiley & Sons, Ltd. KW - ToF-SIMS KW - nanoparticles KW - nano clay KW - polymer KW - food contact material Y1 - 2014 U6 - https://doi.org/10.1002/sia.5546 SN - 0142-2421 SN - 1096-9918 VL - 46 SP - 334 EP - 336 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Goebel, Ronald A1 - Hesemann, Peter A1 - Friedrich, Alwin A1 - Rothe, Regina A1 - Schlaad, Helmut A1 - Taubert, Andreas T1 - Modular thiol-ene chemistry approach towards mesoporous silica monoliths with organically modified pore walls JF - Chemistry - a European journal N2 - The surface modification of mesoporous silica monoliths through thiol-ene chemistry is reported. First, mesoporous silica monoliths with vinyl, allyl, and thiol groups were synthesized through a sol-gel hydrolysis-poly-condensation reaction from tetramethyl orthosilicate (TMOS) and vinyltriethoxysilane, allyltriethoxysilane, and (3-mercaptopropyl) trimethoxysilane, respectively. By variation of the molar ratio of the comonomers TMOS and functional silane, mesoporous silica objects containing different amounts of vinyl, allyl, and thiol groups were obtained. These intermediates can subsequently be derivatized through radical photoaddition reactions either with a thiol or an olefin, depending on the initial pore wall functionality, to yield silica monoliths with different pore-wall chemistries. Nitrogen sorption, small-angle X-ray scattering, solid-state NMR spectroscopy, elemental analysis, thermogravimetric analysis, and redox titration demonstrate that the synthetic pathway influences the morphology and pore characteristics of the resulting monoliths and also plays a significant role in the efficiency of functionalization. Moreover, the different reactivity of the vinyl and allyl groups on the pore wall affects the addition reaction, and hence, the degree of the pore-wall functionalization. This report demonstrates that thiol-ene photoaddition reactions are a versatile platform for the generation of a large variety of organically modified silica monoliths with different pore surfaces. KW - mesoporous materials KW - photochemistry KW - sol-gel processes KW - surface chemistry Y1 - 2014 U6 - https://doi.org/10.1002/chem.201403982 SN - 0947-6539 SN - 1521-3765 VL - 20 IS - 52 SP - 17579 EP - 17589 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Winter, Alette A1 - Thiel, Kerstin A1 - Zabel, Andre A1 - Klamroth, Tillmann A1 - Poeppl, Andreas A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Taubert, Andreas A1 - Strauch, Peter T1 - Tetrahalidocuprates(II) - structure and EPR spectroscopy. Part 2: tetrachloridocuprates(II) JF - New journal of chemistry N2 - We present and discuss the results of crystallographic and electron paramagnetic resonance (EPR) spectroscopic analyses of five tetrachloridocuprate(II) complexes to supply a useful tool for the structural characterisation of the [CuCl4](2-) moiety in the liquid state, for example in ionic liquids, or in solution. Bis(benzyltriethylammonium)-, bis(trimethylphenylammonium)-, bis(ethyltriphenylphosphonium)-, bis(benzyltriphenylphosphonium)-, and bis(tetraphenylarsonium) tetrachloridocuprate(II) were synthesised and characterised by elemental, IR, EPR and X-ray analyses. The results of the crystallographic analyses show distorted tetrahedral coordination geometry of all [CuCl4](2-) anions in the five complexes and prove that all investigated complexes are stabilised by hydrogen bonds of different intensities. Despite the use of sterically demanding ammonium, phosphonium and arsonium cations to obtain the separation of the paramagnetic Cu(II) centres for EPR spectroscopy no hyperfine structure was observed in the EPR spectra but the principal values of the electron Zeeman tensor, g(parallel to) and g(perpendicular to), could be determined. With these EPR data and the crystallographic parameters we were able to carry out a correlation study to anticipate the structural situation of tetrachloridocuprates in different physical states. This correlation is in good agreement with DFT calculations. Y1 - 2014 U6 - https://doi.org/10.1039/c3nj01039b SN - 1144-0546 SN - 1369-9261 VL - 38 IS - 3 SP - 1019 EP - 1030 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Salama, Ahmed A1 - Neumann, Mike A1 - Günter, Christina A1 - Taubert, Andreas T1 - Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials JF - Beilstein journal of nanotechnology N2 - Cellulose/calcium phosphate hybrid materials were synthesized via an ionic liquid-assisted route. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis show that, depending on the reaction conditions, cellulose/hydroxyapatite, cellulose/ chlorapatite, or cellulose/monetite composites form. Preliminary studies with MC3T3-E1 pre-osteoblasts show that the cells proliferate on the hybrid materials suggesting that the ionic liquid-based process yields materials that are potentially useful as scaffolds for regenerative therapies. KW - biomineralization KW - calcium phosphate KW - carbohydrates KW - cellulose KW - hybrid materials KW - ionic liquid Y1 - 2014 U6 - https://doi.org/10.3762/bjnano.5.167 SN - 2190-4286 VL - 5 SP - 1553 EP - 1568 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - JOUR A1 - Mai, Tobias A1 - Rakhmatullina, Ekaterina A1 - Bleek, Katrin A1 - Boye, Susanne A1 - Yuan, Jiayin A1 - Voelkel, Antje A1 - Graewert, Marlies A1 - Cheaib, Zeinab A1 - Eick, Sigrun A1 - Günter, Christina A1 - Lederer, Albena A1 - Lussi, Adrian A1 - Taubert, Andreas T1 - Poly(ethylene oxide)-b-poly(3-sulfopropyl methacrylate) block copolymers for calcium phosphate mineralization and biofilm inhibition JF - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences N2 - Poly(ethylene oxide) (PEO) has long been used as an additive in toothpaste, partly because it reduces biofilm formation on teeth. It does not, however, reduce the formation of dental calculus or support the remineralization of dental enamel or dentine. The present article describes the synthesis of new block copolymers on the basis of PEO and poly(3-sulfopropyl methacrylate) blocks using atom transfer radical polymerization. The polymers have very large molecular weights (over 10(6) g/mol) and are highly water-soluble. They delay the precipitation of calcium phosphate from aqueous solution but, upon precipitation, lead to relatively monodisperse hydroxyapatite (HAP) spheres. Moreover, the polymers inhibit the bacterial colonization of human enamel by Streptococcus gordonii, a pioneer bacterium in oral biofilm formation, in vitro. The formation of well-defined HAP spheres suggests that a polymer-induced liquid precursor phase could be involved in the precipitation process. Moreover, the inhibition of bacterial adhesion suggests that the polymers could be utilized in caries prevention. Y1 - 2014 U6 - https://doi.org/10.1021/bm500888q SN - 1525-7797 SN - 1526-4602 VL - 15 IS - 11 SP - 3901 EP - 3914 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Hentrich, Doreen A1 - Junginger, Mathias A1 - Bruns, Michael A1 - Börner, Hans Gerhard A1 - Brandt, Jessica A1 - Brezesinski, Gerald A1 - Taubert, Andreas T1 - Interface-controlled calcium phosphate mineralization BT - effect of oligo(aspartic acid)-rich interfaces JF - CrystEngComm N2 - The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air–water and air–buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression–expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH. Y1 - 2015 U6 - https://doi.org/10.1039/C4CE02274B SN - 1466-8033 IS - 17 SP - 6901 EP - 6913 PB - Royal Society of Chemistry CY - London ER - TY - JOUR A1 - Kirchhecker, Sarah A1 - Tröger-Müller, Steffen A1 - Bake, Sebastian A1 - Antonietti, Markus A1 - Taubert, Andreas A1 - Esposito, Davido T1 - Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions JF - Green chemistry N2 - Fully renewable pyridinium ionic liquids were synthesised via the hydrothermal decarboxylation of pyridinium zwitterions derived from furfural and amino acids in flow. The functionality of the resulting ionic liquid (IL) can be tuned by choice of different amino acids as well as different natural carboxylic acids as the counterions. A representative member of this new class of ionic liquids was successfully used for the synthesis of ionogels and as a solvent for the Heck coupling. Y1 - 2015 U6 - https://doi.org/10.1039/c5gc00913h SN - 1463-9262 SN - 1463-9270 VL - 8 IS - 17 SP - 4151 EP - 4156 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Leroux, Fabrice A1 - Rabu, Pierre A1 - Sommerdijk, Nico A. J. M. A1 - Taubert, Andreas T1 - Two-Dimensional Hybrid Materials: Transferring Technology from Biology to Society JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - Hybrid materials are at the forefront of modern research and technology; hence a large number of publications on hybrid materials has already appeared in the scientific literature. This essay focuses on the specifics and peculiarities of hybrid materials based on two-dimensional (2D) building blocks and confinements, for two reasons: (1) 2D materials have a very broad field of application, but they also illustrate many of the scientific challenges the community faces, both on a fundamental and an application level; (2) all authors of this essay are involved in research on 2D materials, but their perspective and vision of how the field will develop in the future and how it is possible to benefit from these new developments are rooted in very different scientific subfields. The current article will thus present a personal, yet quite broad, account of how hybrid materials, specifically 2D hybrid materials, will provide means to aid modern societies in fields as different as healthcare and energy. Y1 - 2015 U6 - https://doi.org/10.1002/ejic.201500153 SN - 1434-1948 SN - 1099-0682 IS - 7 SP - 1089 EP - 1095 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Hentrich, Doreen A1 - Junginger, Mathias A1 - Bruns, Michael A1 - Boerner, Hans G. A1 - Brandt, Jessica A1 - Brezesinski, Gerald A1 - Taubert, Andreas T1 - Interface-controlled calcium phosphate mineralization: effect of oligo(aspartic acid)-rich interfaces JF - CrystEngComm N2 - The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air-water and air-buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression-expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH. Y1 - 2015 U6 - https://doi.org/10.1039/c4ce02274b SN - 1466-8033 VL - 17 IS - 36 SP - 6901 EP - 6913 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Kirchhecker, Sarah A1 - Tröger-Müller, Steffen A1 - Bake, Sebastian A1 - Antonietti, Markus A1 - Taubert, Andreas A1 - Esposito, Davide T1 - Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions JF - Green chemistry : an international journal and green chemistry resource N2 - Fully renewable pyridinium ionic liquids were synthesised via the hydrothermal decarboxylation of pyridinium zwitterions derived from furfural and amino acids in flow. The functionality of the resulting ionic liquid (IL) can be tuned by choice of different amino acids as well as different natural carboxylic acids as the counter-ions. A representative member of this new class of ionic liquids was successfully used for the synthesis of ionogels and as a solvent for the Heck coupling. Y1 - 2015 U6 - https://doi.org/10.1039/c5gc00913h SN - 1463-9262 SN - 1463-9270 VL - 17 IS - 8 SP - 4151 EP - 4156 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Mai, Tobias A1 - Boye, Susanne A1 - Yuan, Jiayin A1 - Völkel, Antje A1 - Gräwert, Marlies A1 - Günter, Christina A1 - Lederer, Albena A1 - Taubert, Andreas T1 - Poly(ethylene oxide)-based block copolymers with very high molecular weights for biomimetic calcium phosphate mineralization JF - RSC Advances : an international journal to further the chemical sciences N2 - The present article is among the first reports on the effects of poly(ampholyte)s and poly(betaine)s on the biomimetic formation of calcium phosphate. We have synthesized a series of di- and triblock copolymers based on a non-ionic poly(ethylene oxide) block and several charged methacrylate monomers, 2-(trimethylammonium)ethyl methacrylate chloride, 2-((3-cyanopropyl)-dimethylammonium)ethyl methacrylate chloride, 3-sulfopropyl methacrylate potassium salt, and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide. The resulting copolymers are either positively charged, ampholytic, or betaine block copolymers. All the polymers have very high molecular weights of over 106 g mol−1. All polymers are water-soluble and show a strong effect on the precipitation and dissolution of calcium phosphate. The strongest effects are observed with triblock copolymers based on a large poly(ethylene oxide) middle block (nominal Mn = 100 000 g mol−1). Surprisingly, the data show that there is a need for positive charges in the polymers to exert tight control over mineralization and dissolution, but that the exact position of the charge in the polymer is of minor importance for both calcium phosphate precipitation and dissolution. Y1 - 2015 U6 - https://doi.org/10.1039/c5ra20035k SN - 2046-2069 IS - 5 SP - 103494 EP - 103505 PB - RSC Publishing CY - London ER - TY - JOUR A1 - Mai, Tobias A1 - Boye, Susanne A1 - Yuan, Jiayin A1 - Voelkel, Antje A1 - Graewert, Marlies A1 - Günter, Christina A1 - Lederer, Albena A1 - Taubert, Andreas T1 - Poly(ethylene oxide)-based block copolymers with very high molecular weights for biomimetic calcium phosphate mineralization JF - RSC Advances N2 - The present article is among the first reports on the effects of poly(ampholyte)s and poly(betaine) s on the biomimetic formation of calcium phosphate. We have synthesized a series of di- and triblock copolymers based on a non-ionic poly(ethylene oxide) block and several charged methacrylate monomers, 2-(trimethylammonium) ethyl methacrylate chloride, 2-((3-cyanopropyl)-dimethylammonium)ethyl methacrylate chloride, 3-sulfopropyl methacrylate potassium salt, and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide. The resulting copolymers are either positively charged, ampholytic, or betaine block copolymers. All the polymers have very high molecular weights of over 10(6) g mol(-1). All polymers are water-soluble and show a strong effect on the precipitation and dissolution of calcium phosphate. The strongest effects are observed with triblock copolymers based on a large poly(ethylene oxide) middle block (nominal M-n = 100 000 g mol(-1)). Surprisingly, the data show that there is a need for positive charges in the polymers to exert tight control over mineralization and dissolution, but that the exact position of the charge in the polymer is of minor importance for both calcium phosphate precipitation and dissolution. Y1 - 2015 U6 - https://doi.org/10.1039/c5ra20035k SN - 2046-2069 VL - 5 IS - 125 SP - 103494 EP - 103505 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Göbel, Ronald A1 - Stoltenberg, Marcus A1 - Krehl, Stefan A1 - Biolley, Christine A1 - Rothe, Regina A1 - Schmidt, Bernd A1 - Hesemann, Peter A1 - Taubert, Andreas T1 - A Modular Approach towards Mesoporous Silica Monoliths with Organically Modified Pore Walls: Nucleophilic Addition, Olefin Metathesis, and Cycloaddition JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - We have synthesized mesoporous silica (monoliths) with defined surface chemistry by means of a number of addition reactions: (i) coupling of an isocyanate to a surface-immobilized thiol, (ii) addition of an epoxide to a surface-immobilized thiol, (iii) cross-metathesis between two olefins, and (iv) Huisgen [2+3] cycloaddition of an alkyne-functionalized silica monolith with an azide. Functionalization of the mesopores was observed, but there are significant differences between individual approaches. Isocyanate and epoxide additions lead to high degrees of functionalization, whereas olefin metathesis and [2+3] cycloaddition are less effective. We further show that the efficiency of the modification is about twice as high in mesoporous silica particles than in macroscopic silica monoliths. KW - Mesoporous materials KW - Hybrid materials KW - Surface chemistry KW - Click chemistry KW - Nucleophilic addition Y1 - 2016 U6 - https://doi.org/10.1002/ejic.201500638 SN - 1434-1948 SN - 1099-0682 VL - 6 SP - 2088 EP - 2099 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Zhang, Weiyi A1 - Willa, Christoph A1 - Sun, Jian-Ke A1 - Guterman, Ryan A1 - Taubert, Andreas A1 - Yuan, Jiayin T1 - Polytriazolium poly(ionic liquid) bearing triiodide anions: Synthesis, basic properties and electrochemical behaviors JF - Polymer : the international journal for the science and technology of polymers N2 - 4-Methyl-1-vinyl-1,2,4-triazolium triiodide ionic liquid and its polymer poly(4-methyl-1-vinyl-1,2,4-triazolium) triiodide were prepared for the first time from their iodide precursors via the reaction of iodide (I-) with elemental iodine (I-2). The change from iodide to triiodide (I-3(-)) was found to introduce particular variations in the physical properties of these two compounds, including lower melting point/glass transition temperature and altered solubility. The compounds were characterized by single-crystal X-ray diffraction, elemental analysis, and their electrochemical properties examined in solution and in the solid-state. Compared with their iodide analogues, the triiodide salts exhibited lower electrical impedance and higher current in the cyclic voltammetry. We found that poly(4-methyl-1,2,4-triazolium triiodide) was proven to be a promising solid polymer electrolyte candidate. (C) 2017 Elsevier Ltd. All rights reserved. KW - Poly(ionic liquid) KW - Solid polymer electrolyte KW - Grotthuss mechanism KW - Triiodide "network" Y1 - 2017 U6 - https://doi.org/10.1016/j.polymer.2017.07.059 SN - 0032-3861 SN - 1873-2291 VL - 124 SP - 246 EP - 251 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Hentrich, Doreen A1 - Brezesinski, Gerald A1 - Kuebel, Christian A1 - Bruns, Michael A1 - Taubert, Andreas T1 - Cholesteryl Hemisuccinate Monolayers Efficiently Control Calcium Phosphate Nucleation and Growth JF - Crystal growth & design : integrating the fields of crystal engineering and crystal growth for the synthesis and applications of new materials N2 - The article describes the phase behavior of cholesteryl hemisuccinate at the air-liquid interface and its effect on calcium phosphate (CP) mineralization. The amphiphile forms stable monolayers with phase transitions at the air-liquid interface from a gas to a tilted liquid-condensed (TLC) and finally to an untilted liquid-condensed (ULC) phase. CP mineralization beneath these monolayers leads to crumpled CP layers made from individual plates. The main crystal phase is octacalcium phosphate (OCP) along with a minor fraction of hydroxyapatite (HAP), as confirmed by X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, bright field transmission electron microscopy, and electron diffraction. Y1 - 2017 U6 - https://doi.org/10.1021/acs.cgd.7b00753 SN - 1528-7483 SN - 1528-7505 VL - 17 SP - 5764 EP - 5774 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Peh, Eddie A1 - Liedel, Clemens A1 - Taubert, Andreas A1 - Tauer, Klaus T1 - Composition inversion to form calcium carbonate mixtures JF - CrystEngComm N2 - Composition inversion takes place in equimolar solid mixtures of sodium or ammonium carbonate and calcium chloride with respect to the combination of anions and cations leading to the corresponding chloride and calcite in complete conversion. The transformation takes place spontaneously under a variety of different situations, even in a powdery mixture resting under ambient conditions. Powder X-ray diffraction data and scanning electron microscopy micrographs are presented to describe the course of the reaction and to characterize the reaction products. The incomplete reaction in the interspace between two compressed tablets of pure starting materials leads to an electric potential due to the presence of uncompensated charges. Y1 - 2017 U6 - https://doi.org/10.1039/c7ce00433h SN - 1466-8033 VL - 19 SP - 3573 EP - 3583 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Lutze, Jana A1 - Bañares, Miguel A. A1 - Pita, Marcos A1 - Haase, Andrea A1 - Luch, Andreas A1 - Taubert, Andreas T1 - alpha-((4-Cyanobenzoyl)oxy)-omega-methyl poly(ethylene glycol) BT - a new stabilizer for silver nanoparticles JF - Beilstein journal of nanotechnology N2 - The article describes the synthesis and properties of alpha-((4-cyanobenzoyl)oxy)-omega-methyl poly(ethylene glycol), the first poly(ethylene glycol) stabilizer for metal nanoparticles that is based on a cyano rather than a thiol or thiolate anchor group. The silver particles used to evaluate the effectiveness of the new stabilizer typically have a bimodal size distribution with hydrodynamic diameters of ca. 13 and ca. 79 nm. Polymer stability was evaluated as a function of the pH value both for the free stabilizer and for the polymers bound to the surface of the silver nanoparticles using H-1 NMR spectroscopy and zeta potential measurements. The polymer shows a high stability between pH 3 and 9. At pH 12 and higher the polymer coating is degraded over time suggesting that alpha-((4-cyanobenzoyl) oxy)-omega-methyl poly(ethylene glycol) is a good stabilizer for metal nanoparticles in aqueous media unless very high pH conditions are present in the system. The study thus demonstrates that cyano groups can be viable alternatives to the more conventional thiol/thiolate anchors. KW - cyano anchor group KW - poly(ethylene glycol) KW - polymer coating KW - silver nanoparticles Y1 - 2017 U6 - https://doi.org/10.3762/bjnano.8.67 SN - 2190-4286 VL - 8 SP - 627 EP - 635 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - JOUR A1 - Taubert, Andreas A1 - Löbbicke, Ruben A1 - Kirchner, Barbara A1 - Leroux, Fabrice T1 - First examples of organosilica-based ionogels BT - synthesis and electrochemical behavior JF - Beilstein journal of nanotechnology N2 - The article describes the synthesis and properties of new ionogels for ion transport. A new preparation process using an organic linker, bis(3-(trimethoxysilyl) propyl) amine (BTMSPA), yields stable organosilica matrix materials. The second ionogel component, the ionic liquid 1-methyl-3-(4-sulfobutyl) imidazolium 4-methylbenzenesulfonate, [BmimSO(3)H][PTS], can easily be prepared with near-quantitative yields. [BmimSO(3)H][PTS] is the proton conducting species in the ionogel. By combining the stable organosilica matrix with the sulfonated ionic liquid, mechanically stable, and highly conductive ionogels with application potential in sensors or fuel cells can be prepared. KW - ionic liquids KW - ionogels KW - organosilica KW - proton conductivity Y1 - 2017 U6 - https://doi.org/10.3762/bjnano.8.77 SN - 2190-4286 VL - 8 SP - 736 EP - 751 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - JOUR A1 - Abouserie, Ahed A1 - Zehbe, Kerstin A1 - Metzner, Philipp A1 - Kelling, Alexandra A1 - Günter, Christina A1 - Schilde, Uwe A1 - Strauch, Peter A1 - Körzdörfer, Thomas A1 - Taubert, Andreas T1 - Alkylpyridinium Tetrahalidometallate Ionic Liquids and Ionic Liquid Crystals: Insights into the Origin of Their Phase Behavior JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - Six N-alkylpyridinium salts [CnPy](2)[MCl4] (n = 4 or 12 and M = Co, Cu, Zn) were synthesized, and their structure and thermal properties were studied. The [C4Py](2)[MCl4] compounds are monoclinic and crystallize in the space group P2(1)/n. The crystals of the longer chain analogues [C12Py](2)[MCl4] are triclinic and crystallize in the space group P (1) over bar. Above the melting temperature, all compounds are ionic liquids (ILs). The derivatives with the longer C12 chain exhibit liquid crystallinity and the shorter chain compounds only show a melting transition. Consistent with single-crystal analysis, electron paramagnetic resonance spectroscopy suggests that the [CuCl4](2-) ions in the Cu-based ILs have a distorted tetrahedral geometry. KW - Ionic liquids KW - Alkylpyridinium salts KW - Structure elucidation KW - Phase transitions Y1 - 2017 U6 - https://doi.org/10.1002/ejic.201700826 SN - 1434-1948 SN - 1099-0682 SP - 5640 EP - 5649 PB - Wiley-VCH CY - Weinheim ER -