TY - GEN A1 - Taubert, Andreas A1 - Balischewski, Christian A1 - Hentrich, Doreen A1 - Elschner, Thomas A1 - Eidner, Sascha A1 - Günter, Christina A1 - Behrens, Karsten A1 - Heinze, Thomas T1 - Water-soluble cellulose derivatives are sustainable additives for biomimetic calcium phosphate mineralization N2 - The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer) contents reach 10% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble) cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 354 KW - cellulose KW - polyamine KW - polyammonium salt KW - polycarboxylate KW - polyzwitterion KW - calcium phosphate KW - biomineralization KW - brushite KW - hydroyxapatite KW - biomaterial Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400453 ER - TY - JOUR A1 - Taubert, Andreas A1 - Balischewski, Christian A1 - Hentrich, Doreen A1 - Elschner, Thomas A1 - Eidner, Sascha A1 - Günter, Christina A1 - Behrens, Karsten A1 - Heinze, Thomas T1 - Water-Soluble Cellulose Derivatives Are Sustainable Additives for Biomimetic Calcium Phosphate Mineralization JF - Inorganics : open access journal N2 - The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer) contents reach 10% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble) cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials. KW - cellulose KW - polyamine KW - polyammonium salt KW - polycarboxylate KW - polyzwitterion KW - calcium phosphate KW - biomineralization KW - brushite KW - hydroyxapatite KW - biomaterial Y1 - 2016 U6 - https://doi.org/10.3390/inorganics4040033 SN - 2304-6740 VL - 4 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ugwuja, Chidinma G. A1 - Adelowo, Olawale O. A1 - Ogunlaja, Aemere A1 - Omorogie, Martins O. A1 - Olukanni, Olumide D. A1 - Ikhimiukor, Odion O. A1 - Iermak, Ievgeniia A1 - Kolawole, Gabriel A. A1 - Günter, Christina A1 - Taubert, Andreas A1 - Bodede, Olusola A1 - Moodley, Roshila A1 - Inada, Natalia M. A1 - Camargo, Andrea S.S. de A1 - Unuabonah, Emmanuel Iyayi T1 - Visible-Light-Mediated Photodynamic Water Disinfection @ Bimetallic-Doped Hybrid Clay Nanocomposites JF - ACS applied materials & interfaces N2 - This study reports a new class of photocatalytic hybrid clay nanocomposites prepared from low-cost sources (kaolinite clay and Carica papaya seeds) doped with Zn and Cu salts via a solvothermal process. X-ray diffraction analysis suggests that Cu-doping and Cu/Zn-doping introduce new phases into the crystalline structure of Kaolinite clay, which is linked to the reduced band gap of kaolinite from typically between 4.9 and 8.2 eV to 2.69 eV for Cu-doped and 1.5 eV for Cu/Zn hybrid clay nanocomposites (Nisar, J.; Arhammar, C.; Jamstorp, E.; Ahuja, R. Phys. Rev. B 2011, 84, 075120). In the presence of solar light irradiation, Cu- and Cu/Zn-doped nanocomposites facilitate the electron hole pair separation. This promotes the generation of singlet oxygen which in turn improves the water disinfection efficiencies of these novel nanocomposite materials. The nanocomposite materials were further characterized using high-resolution scanning electron microscopy, fluorimetry, therrnogravimetric analysis, and Raman spectroscopy. The breakthrough times of the nanocomposites for a fixed bed mode of disinfection of water contaminated with 2.32 x 10(7) cfu/mL E. coli ATCC 25922 under solar light irradiation are 25 h for Zn-doped, 30 h for Cu-doped, and 35 h for Cu/Zn-doped nanocomposites. In the presence of multidrug and multimetal resistant strains of E. coli, the breakthrough time decreases significantly. Zn-only doped nanocomposites are not photocatalytically active. In the absence of light, the nanocomposites are still effective in decontaminating water, although less efficient than under solar light irradiation. Electrostatic interaction, metal toxicity, and release of singlet oxygen (only in the Cu-doped and Cu/Zn-doped nanocomposites) are the three disinfection mechanisms by which these nanocomposites disinfect water. A regrowth study indicates the absence of any living E. coli cells in treated water even after 4 days. These data and the long hydraulic times (under gravity) exhibited by these nanocomposites during photodisinfection of water indicate an unusually high potential of these nanocomposites as efficient, affordable, and sustainable point-of-use systems for the disinfection of water in developing countries. KW - disinfection KW - nanocomposite material KW - multidrug-resistant Escherichia coli KW - water KW - reactive oxygen species Y1 - 2019 U6 - https://doi.org/10.1021/acsami.9b01212 SN - 1944-8244 SN - 1944-8252 VL - 11 IS - 28 SP - 25483 EP - 25494 PB - American Chemical Society CY - Washington, DC ER - TY - JOUR A1 - Shkilnyy, Andriy A1 - Gräf, Ralph A1 - Hiebl, Bernhard A1 - Neffe, Axel T. A1 - Friedrich, Alwin A1 - Hartmann, Juergen A1 - Taubert, Andreas T1 - Unprecedented, low cytotoxicity of spongelike calcium phosphate/poly(ethylene imine) hydrogel composites N2 - Covalently crosslinked PEI hydrogels are efficient templates for calcium phosphate mineralization in SBF. In contrast to the PEI hydrogels, non-crosslinked PEI does not lead to calcium phosphate nucleation and growth in SBF. The precipitate is a mixture of brushite and hydroxyapatite. The PEI/calcium phosphate composite material exhibits a sponge like morphology and a chemical composition that is interesting for implants. Cytotoxicity tests using Dictyostelium discoideum amoebae show that both the non-mineralized and mineralized hydrogels have a very low cytotoxicity. This suggests that next generation PEI hydrogels, where also the degradation products are non-toxic, could be interesting for biomedical applications. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/77002860 U6 - https://doi.org/10.1002/mabi.200800266 SN - 1616-5187 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 - Xie, Zai-Lai A1 - Jelicic, Aleksandra A1 - Wang, Feipeng A1 - Rabu, Pierre A1 - Friedrich, Alwin A1 - Beuermann, Sabine A1 - Taubert, Andreas T1 - Transparent, flexible, and paramagnetic ionogels based on PMMA and the iron-based ionic liquid 1-butyl-3- methylimidazolium tetrachloroferrate(III) [Bmim][FeCl4] N2 - The iron-containing ionic liquid (IL) 1-butyl-3-methylimidazolium tetrachloroferrate(III) [Bmim][FeCl4] has been used as a building block in the synthesis of transparent, ion-conducting, and paramagnetic ionogels. UV/Vis spectroscopy shows that the coordination around the Fe(III) ion does slightly change upon incorporation of the IL into PMMA. The thermal stability of the PMMA increases significantly with IL incorporation. In particular, the onset weight loss observed at ca. 265 degrees C for pure PMMA is completely suppressed. The ionic conductivity shows a strong temperature dependence and increases with increasing IL weight fractions. The magnetic properties are similar to those reported for the pure IL and are not affected by the incorporation into the PMMA matrix. The resulting ionogel is thus an interesting prototype for soft, flexible, and transparent materials combining the mechanical properties of the matrix with the functionality of the metal-containing IL, such as magnetism. Y1 - 2010 UR - http://www.rsc.org/Publishing/Journals/jm/index.asp U6 - https://doi.org/10.1039/C0jm01733g SN - 0959-9428 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 - 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 - 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 - Lehmann, Frederike A1 - Franz, Alexandra A1 - Toebbens, Daniel M. A1 - Levcenco, Sergej A1 - Unold, Thomas A1 - Taubert, Andreas A1 - Schorr, Susan T1 - The phase diagram of a mixed halide (Br, I) hybrid perovskite obtained by synchrotron X-ray diffraction JF - RSC Advances N2 - By using synchrotron X-ray powder diffraction, the temperature dependent phase diagram of the hybrid perovskite tri-halide compounds, methyl ammonium lead iodide (MAPbI3, MA+ = CH3NH3+) and methyl ammonium lead bromide (MAPbBr3), as well as of their solid solutions, has been established. The existence of a large miscibility gap between 0.29 ≤ x ≤ 0.92 (±0.02) for the MAPb(I1−xBrx)3 solid solution has been proven. A systematic study of the lattice parameters for the solid solution series at room temperature revealed distinct deviations from Vegard's law. Furthermore, temperature dependent measurements showed that a strong temperature dependency of lattice parameters from the composition is present for iodine rich compositions. In contrast, the bromine rich compositions show an unusually low dependency of the phase transition temperature from the degree of substitution. Y1 - 2019 U6 - https://doi.org/10.1039/c8ra09398a SN - 2046-2069 VL - 9 IS - 20 SP - 11151 EP - 11159 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Abouserie, Ahed A1 - Schilde, Uwe A1 - Taubert, Andreas T1 - The crystal structure of N-butylpyridinium bis(μ2-dichlorido)-tetrachloridodicopper(II), C₁₈H₂₈N₂Cu₂Cl₆ JF - Zeitschrift für Kristallographie - New Crystal Structures N2 - C₉H₁₄Cl₃CuN, monoclinic, P2₁/n (no. 14), a = 9.6625(6) Å, b = 9.3486(3) Å, c = 14.1168(8) Å, β = 102.288(5)°, V = 1245.97(11) ų, Z = 4, Rgₜ(F) = 0.0182, wRᵣₑf(F²) = 0.0499, T = 210(2) K. KW - Ionic Liquid Precursor KW - Thermochromism KW - Salts KW - Nanostructures KW - Catalysis KW - Solvents KW - Complex KW - Gas Y1 - 2018 U6 - https://doi.org/10.1515/NCRS-2018-0099 SN - 2194-4946 SN - 2196-7105 VL - 233 IS - 4 SP - 743 EP - 746 PB - de Gruyter CY - Berlin und München ER - TY - GEN A1 - Abouserie, Ahed A1 - Schilde, Uwe A1 - Taubert, Andreas T1 - The crystal structure of N-butylpyridinium bis(μ2-dichlorido)-tetrachloridodicopper(II), C₁₈H₂₈N₂Cu₂Cl₆ T2 - Zeitschrift für Kristallographie - New Crystal Structures N2 - C₉H₁₄Cl₃CuN, monoclinic, P2₁/n (no. 14), a = 9.6625(6) Å, b = 9.3486(3) Å, c = 14.1168(8) Å, β = 102.288(5)°, V = 1245.97(11) ų, Z = 4, Rgₜ(F) = 0.0182, wRᵣₑf(F²) = 0.0499, T = 210(2) K. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 465 KW - Ionic Liquid Precursor KW - Thermochromism KW - Salts KW - Nanostructures KW - Catalysis KW - Solvents KW - Complex KW - Gas Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-417310 ER - TY - JOUR A1 - Balischewski, Christian A1 - Bhattacharyya, Biswajit A1 - Sperlich, Eric A1 - Günter, Christina A1 - Beqiraj, Alkit A1 - Klamroth, Tillmann A1 - Behrens, Karsten A1 - Mies, Stefan A1 - Kelling, Alexandra A1 - Lubahn, Susanne A1 - Holtzheimer, Lea A1 - Nitschke, Anne A1 - Taubert, Andreas T1 - Tetrahalidometallate(II) ionic liquids with more than one metal BT - the effect of bromide versus chloride JF - Chemistry - a European journal N2 - Fifteen N-butylpyridinium salts - five monometallic [C4Py](2)[MBr4] and ten bimetallic [C4Py](2)[(M0.5M0.5Br4)-M-a-Br-b] (M=Co, Cu, Mn, Ni, Zn) - were synthesized, and their structures and thermal and electrochemical properties were studied. All the compounds are ionic liquids (ILs) with melting points between 64 and 101 degrees C. Powder and single-crystal X-ray diffraction show that all ILs are isostructural. The electrochemical stability windows of the ILs are between 2 and 3 V. The conductivities at room temperature are between 10(-5) and 10(-6) S cm(-1). At elevated temperatures, the conductivities reach up to 10(-4) S cm(-1) at 70 degrees C. The structures and properties of the current bromide-based ILs were also compared with those of previous examples using chloride ligands, which illustrated differences and similarities between the two groups of ILs. KW - electrochemistry KW - ionic liquids KW - metal-containing ionic liquids; KW - N-butylpyridinium bromide KW - tetrahalidometallates Y1 - 2022 U6 - https://doi.org/10.1002/chem.202201068 SN - 1521-3765 VL - 28 IS - 64 PB - Wiley-VCH CY - Weinheim 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 - GEN A1 - Winter, Alette A1 - Thiel, Kerstin A1 - Zabel, André A1 - Klamroth, Tillmann A1 - Pöppl, Andreas A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Taubert, Andreas A1 - Strauch, Peter T1 - Tetrahalidocuprates(II) – structure and EPR spectroscopy BT - Part 2: tetrachloridocuprates(II) 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∥ and g⊥, 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 240 KW - electron-spin resonance KW - liquid-crystal precursors KW - copper(II) halide salts KW - ionic liquid KW - square planar KW - tetrachlorocuprate(II) salts KW - molecular-structure KW - magnetic-properties KW - paramagnetic-resonance KW - temperature phase Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95012 SP - 1019 EP - 1030 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 - Pan, Xuefeng A1 - Sarhan, Radwan Mohamed A1 - Kochovski, Zdravko A1 - Chen, Guosong A1 - Taubert, Andreas A1 - Mei, Shilin A1 - Lu, Yan T1 - Template synthesis of dual-functional porous MoS2 nanoparticles with photothermal conversion and catalytic properties JF - Nanoscale N2 - Advanced catalysis triggered by photothermal conversion effects has aroused increasing interest due to its huge potential in environmental purification. In this work, we developed a novel approach to the fast degradation of 4-nitrophenol (4-Nip) using porous MoS2 nanoparticles as catalysts, which integrate the intrinsic catalytic property of MoS2 with its photothermal conversion capability. Using assembled polystyrene-b-poly(2-vinylpyridine) block copolymers as soft templates, various MoS 2 particles were prepared, which exhibited tailored morphologies (e.g., pomegranate-like, hollow, and open porous structures). The photothermal conversion performance of these featured particles was compared under near-infrared (NIR) light irradiation. Intriguingly, when these porous MoS2 particles were further employed as catalysts for the reduction of 4-Nip, the reaction rate constant was increased by a factor of 1.5 under NIR illumination. We attribute this catalytic enhancement to the open porous architecture and light-to-heat conversion performance of the MoS2 particles. This contribution offers new opportunities for efficient photothermal-assisted catalysis. Y1 - 2022 U6 - https://doi.org/10.1039/d2nr01040b SN - 2040-3372 VL - 14 IS - 18 SP - 6888 EP - 6901 PB - RSC Publ. (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 - Goebel, Ronald A1 - Hesemann, Peter A1 - Weber, Jens A1 - Moeller, Eléonore A1 - Friedrich, Alwin A1 - Beuermann, Sabine A1 - Taubert, Andreas T1 - Surprisingly high, bulk liquid-like mobility of silica-confined ionic liquids N2 - Mesoporous silica monoliths were prepared by the sol - gel technique and. lled with 1-ethyl-3-methyl imidazolium [Emim]-X (X = dicyanamide [N(CN)(2)], ethyl sulfate [EtSO4], thiocyanate [SCN], and triflate [TfO]) ionic liquids (ILs) using a methanol-IL exchange technique. The structure and behavior of the ILs inside the silica monoliths were studied using X-ray scattering, nitrogen sorption, IR spectroscopy, solid-state NMR, and thermal analysis. DSC finds shifts in both the glass transition temperature and melting points (where applicable) of the ILs. Glass transition and melting occur well below room temperature. There is thus no conflict with the NMR and IR data, which show that the ILs are as mobile at room temperature as the bulk (not confined) ILs. The very narrow line widths of the NMR spectra suggest that the ILs in our materials have the highest mobility reported for confined ILs so far. As a result, our data suggest that it is possible to generate IL/silica hybrid materials (ionogels) with bulk-like properties of the IL. This could be interesting for applications in, e.g., the solar cell or membrane fields. Y1 - 2009 UR - http://xlink.rsc.org/jumptojournal.cfm?journal_code=CP U6 - https://doi.org/10.1039/B821833a SN - 1463-9076 ER - TY - JOUR A1 - Schweizer, S. A1 - Schuster, T. A1 - Junginger, Matthias A1 - Siekmeyer, Gerd A1 - Taubert, Andreas T1 - Surface modification of ickel/Titanium Alloy and Titanium Surfaces via a Polyelectrolyte Multilayer/Calcium Phosphate Hybrid Coating N2 - The report shows that simple LbL deposition of positively charged chitosan and negatively charged heparin can be used to efficiently modify the native surface of both NiTi and Ti without any previous treatments. Moreover, mineralization of the polymer multilayers with calcium phosphate leads to surfaces with low contact angles around 70 and 20 degrees for NiTi and Ti, respectively. This suggests that a polymer multilayer/calcium phosphate hybrid coating could be useful for making NiTi or Ti implants that are at the same time antibacterial (via the chitosan), suppress blood clot formation (via the heparin), and favor fast endothelialization (via the improved surface hydrophilicity compared to the respective neat material). Y1 - 2010 UR - http://onlinelibrary.wiley.com/doi/10.1002/mame.200900347/pdf U6 - https://doi.org/10.1002/mame.200900347 SN - 1438-7492 ER - TY - GEN A1 - Schneider, Matthias A1 - Fritzsche, Nora A1 - Puciul-Malinowska, Agnieszka A1 - Balis, Andrzej A1 - Mostafa, Amr A1 - Bald, Ilko A1 - Zapotoczny, Szczepan A1 - Taubert, Andreas T1 - Surface etching of 3D printed poly(lactic acid) with NaOH: a systematic approach T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The article describes a systematic investigation of the effects of an aqueous NaOH treatment of 3D printed poly(lactic acid) (PLA) scaffolds for surface activation. The PLA surface undergoes several morphology changes and after an initial surface roughening, the surface becomes smoother again before the material dissolves. Erosion rates and surface morphologies can be controlled by the treatment. At the same time, the bulk mechanical properties of the treated materials remain unaltered. This indicates that NaOH treatment of 3D printed PLA scaffolds is a simple, yet viable strategy for surface activation without compromising the mechanical stability of PLA scaffolds. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1212 KW - surface modification KW - sodium hydroxide etching KW - poly(lactic acid) KW - 3D printing KW - roughness KW - wettability KW - erosion Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-525088 SN - 1866-8372 IS - 8 ER - TY - JOUR A1 - Schneider, Matthias A1 - Fritzsche, Nora A1 - Puciul-Malinowska, Agnieszka A1 - Balis, Andrzej A1 - Mostafa, Amr A1 - Bald, Ilko A1 - Zapotoczny, Szczepan A1 - Taubert, Andreas T1 - Surface etching of 3D printed poly(lactic acid) with NaOH: a systematic approach JF - Polymers N2 - The article describes a systematic investigation of the effects of an aqueous NaOH treatment of 3D printed poly(lactic acid) (PLA) scaffolds for surface activation. The PLA surface undergoes several morphology changes and after an initial surface roughening, the surface becomes smoother again before the material dissolves. Erosion rates and surface morphologies can be controlled by the treatment. At the same time, the bulk mechanical properties of the treated materials remain unaltered. This indicates that NaOH treatment of 3D printed PLA scaffolds is a simple, yet viable strategy for surface activation without compromising the mechanical stability of PLA scaffolds. KW - surface modification KW - sodium hydroxide etching KW - poly(lactic acid) KW - 3D printing KW - roughness KW - wettability KW - erosion Y1 - 2020 VL - 12 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schneider, Matthias A1 - Fritzsche, Nora A1 - Puciul-Malinowska, Agnieszka A1 - Baliś, Andrzej A1 - Mostafa, Amr A1 - Bald, Ilko A1 - Zapotoczny, Szczepan A1 - Taubert, Andreas T1 - Surface etching of 3D printed poly(lactic acid) with NaOH BT - a systematic approach JF - Polymers N2 - The article describes a systematic investigation of the effects of an aqueous NaOH treatment of 3D printed poly(lactic acid) (PLA) scaffolds for surface activation. The PLA surface undergoes several morphology changes and after an initial surface roughening, the surface becomes smoother again before the material dissolves. Erosion rates and surface morphologies can be controlled by the treatment. At the same time, the bulk mechanical properties of the treated materials remain unaltered. This indicates that NaOH treatment of 3D printed PLA scaffolds is a simple, yet viable strategy for surface activation without compromising the mechanical stability of PLA scaffolds. KW - surface modification KW - sodium hydroxide etching KW - poly(lactic acid) KW - 3D KW - printing KW - roughness KW - wettability KW - erosion Y1 - 2020 U6 - https://doi.org/10.3390/polym12081711 SN - 2073-4360 VL - 12 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ihlenburg, Ramona A1 - Mai, Tobias A1 - Thünemann, Andreas F. A1 - Baerenwald, Ruth A1 - Saalwächter, Kay A1 - Koetz, Joachim A1 - Taubert, Andreas T1 - Sulfobetaine hydrogels with a complex multilength-scale hierarchical structure JF - The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces & biophysical chemistry N2 - Hydrogels with a hierarchical structure were prepared from a new highly water-soluble crosslinker N,N,N',N'-tetramethyl-N,N'-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and from the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The free radical polymerization of the two compounds is rapid and yields near-transparent hydrogels with sizes up to 5 cm in diameter. Rheology shows a clear correlation between the monomer-to-crosslinker ratio and the storage and loss moduli of the hydrogels. Cryo-scanning electron microscopy, low-field nuclear magnetic resonance (NMR) spectroscopy, and small-angle X-ray scattering show that the gels have a hierarchical structure with features spanning the nanometer to the sub-millimeter scale. The NMR study is challenged by the marked inhomogeneity of the gels and the complex chemical structure of the sulfobetaine monomer. NMR spectroscopy shows how these complications can be addressed via a novel fitting approach that considers the mobility gradient along the side chain of methacrylate-based monomers. KW - Defects KW - Hydrogels KW - Nuclear magnetic resonance spectroscopy KW - Scattering KW - X-ray scattering Y1 - 2021 U6 - https://doi.org/10.1021/acs.jpcb.0c10601 SN - 1520-6106 SN - 1520-5207 VL - 125 IS - 13 SP - 3398 EP - 3408 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Ihlenburg, Ramona A1 - Lehnen, Anne-Catherine A1 - Koetz, Joachim A1 - Taubert, Andreas T1 - Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions JF - Polymers / Molecular Diversity Preservation International N2 - New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further. KW - cryogel KW - water treatment KW - dye removal KW - methyl orange KW - methylene blue KW - dye mixture Y1 - 2020 U6 - https://doi.org/10.3390/polym13020208 SN - 2073-4360 VL - 13 IS - 2 PB - MDPI CY - Basel ER - TY - GEN A1 - Ihlenburg, Ramona A1 - Lehnen, Anne-Catherine A1 - Koetz, Joachim A1 - Taubert, Andreas T1 - Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1093 KW - cryogel KW - water treatment KW - dye removal KW - methyl orange KW - methylene blue KW - dye mixture Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-488987 SN - 1866-8372 IS - 1093 ER - TY - JOUR A1 - Zehbe, Kerstin A1 - Lange, Alyna A1 - Taubert, Andreas T1 - Stereolithography Provides Access to 3D Printed lonogels with High Ionic Conductivity JF - Energy Fuels N2 - New ionogels (IGs) were prepared by combination of a series of sulfonate-based ionic liquids (ILs), 1-methyl-3-(4-sulfobutyl)imidazolium para-toluenesulfonate [BmimSO(3)][pTS], 1-methyl-1-butylpiperidiniumsulfonate para-toluenesul-fonate [BmpipSO(3)] [pTS], and 1-methyl-3-(4-sulfobutyl) imidazolium methylsulfonate [BmimSO(3)H][MeSO3] with a commercial stereolithography photoreactive resin. The article describes both the fundamental properties of the ILs and the resulting IGs. The IGs obtained from the ILs and the resin show high ionic conductivity of up to ca. 0.7.10(-4) S/cm at room temperature and 3.4-10(-3) S/cm at 90 degrees C. Moreover, the IGs are thermally stable to about 200 degrees C and mechanically robust. Finally, and most importantly, the article demonstrates that the IGs can be molded three-dimensionally using stereolithography. This provides, for the first time, access to IGs with complex 3D shapes with potential application in battery or fuel cell technology. Y1 - 2019 U6 - https://doi.org/10.1021/acs.energyfuels.9b03379 SN - 0887-0624 SN - 1520-5029 VL - 33 IS - 12 SP - 12885 EP - 12893 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Herold, Heike M. A1 - Aigner, Tamara Bernadette A1 - Grill, Carolin E. A1 - Krüger, Stefanie A1 - Taubert, Andreas A1 - Scheibel, Thomas R. T1 - SpiderMAEn BT - recombinant spider silk-based hybrid materials for advanced energy technology JF - Bioinspired, Biomimetic and Nanobiomaterials N2 - A growing energy demand requires new and preferably renewable energy sources. The infinite availability of solar radiation makes its conversion into storable and transportable energy forms attractive for research as well as for the industry. One promising example of a transportable fuel is hydrogen (H-2), making research into eco-friendly hydrogen production meaningful. Here, a hybrid system was developed using newly designed recombinant spider silk protein variants as a template for mineralization with inorganic titanium dioxide and gold. These bioinspired organic/inorganic hybrid materials allow for hydrogen production upon light irradiation. To begin with, recombinant spider silk proteins bearing titanium dioxide and gold-binding moieties were created and processed into structured films. These films were modified with gold and titanium dioxide in order to produce a photocatalyst. Subsequent testing revealed hydrogen production as a result of light-induced hydrolysis of water. Therefore, the novel setup presented here provides access to a new principle of generating advanced hybrid materials for sustainable hydrogen production and depicts a promising platform for further studies on photocatalytic production of hydrogen, the most promising future fuel. KW - hybrid materials KW - hydrogen KW - photocatalysts Y1 - 2019 U6 - https://doi.org/10.1680/jbibn.18.00007 SN - 2045-9858 SN - 2045-9866 VL - 8 IS - 1 SP - 99 EP - 108 PB - ICE Publishing CY - Westminister 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 - Kind, Lucy A1 - Plamper, Felix A. A1 - Goebel, Ronald A1 - Mantion, Alexandre A1 - Mueller, Axel H. E. A1 - Pieles, Uwe A1 - Taubert, Andreas A1 - Meier, Wolfgang P. T1 - Silsesquioxane/polyamine nanoparticle-templated formation of star- or raspberry-like silica nanoparticles N2 - Silica is an important mineral in biology and technology, and many protocols have been developed for the synthesis of complex silica architectures. The current report shows that silsesquioxane nanoparticles carrying polymer arms on their surface are efficient templates for the fabrication of silica particles with a star- or raspberry-like morphology. The shape of the resulting particles depends on the chemistry of the polymer arms. With poly(N,N- dimethylaminoethyl methacrylate) (PDMAEMA) arms, spherical particles with a less electron dense core form. With poly {[2- (methacryloyloxy)ethyl] trimethylammonium iodide} (PMETAI), star- or raspberry-like particles form. Electron microscopy, electron tomography, and small-angle X-ray scattering show that the resulting silica particles have a complex structure, where a silsequioxane nanoparticle carrying the polymer arms is in the center. Next is a region that is polymer-rich. The outermost region of the particle is a silica layer, where the outer parts of the polymer arms are embedded. Time- resolved zeta-potential and pH measurements, dynamic light scattering, and electron microscopy reveal that silica formation proceeds differently if PDMAEMA is exchanged for PMETAI. Y1 - 2009 UR - http://pubs.acs.org/journal/langd5 U6 - https://doi.org/10.1021/La900229n SN - 0743-7463 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 - 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 - 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 - 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 - 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 - GEN 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 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 198 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-81390 ER - TY - JOUR A1 - Hamed Misbah, Mohamed A1 - Santos, Mercedes A1 - Quintanilla, Luis A1 - Günter, Christina A1 - Alonso, Matilde A1 - Taubert, Andreas A1 - Carlos Rodriguez-Cabello, Jose T1 - Recombinant DNA technology and click chemistry: a powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization JF - Beilstein journal of nanotechnology N2 - Understanding the mechanisms responsible for generating different phases and morphologies of calcium phosphate by elastin-like recombinamers is supreme for bioengineering of advanced multifunctional materials. The generation of such multifunctional hybrid materials depends on the properties of their counterparts and the way in which they are assembled. The success of this assembly depends on the different approaches used, such as recombinant DNA technology and click chemistry. In the present work, an elastin-like recombinamer bearing lysine amino acids distributed along the recombinamer chain has been cross-linked via Huisgen [2 + 3] cycloaddition. The recombinamer contains the SN(A)15 peptide domains inspired by salivary statherin, a peptide epitope known to specifically bind to and nucleate calcium phosphate. The benefit of using click chemistry is that the hybrid elastin-like-statherin recombinamers cross-link without losing their fibrillar structure. Mineralization of the resulting hybrid elastin-like-statherin recombinamer hydrogels with calcium phosphate is described. Thus, two different hydroxyapatite morphologies (cauliflower- and plate-like) have been formed. Overall, this study shows that crosslinking elastin-like recombinamers leads to interesting matrix materials for the generation of calcium phosphate composites with potential applications as biomaterials. KW - calcium phosphate KW - elastin-like recombinamers KW - hydroxyapatite KW - mineralization KW - SN(A)15 Y1 - 2017 U6 - https://doi.org/10.3762/bjnano.8.80 SN - 2190-4286 VL - 8 SP - 772 EP - 783 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - JOUR A1 - Navarro, Salvador A1 - Shkilnyy, Andriy A1 - Tiersch, Brigitte A1 - Taubert, Andreas A1 - Menzel, Henning T1 - Preparation, characterization, and thermal gelation of amphiphilic alkyl-poly(ethyleneimine) N2 - Amphiphilic alkyl-poly(ethyleneimine)s (alkyl-PEI) with different degrees of polymerization have been produced by alkaline hydrolysis of alkyl-poly(2-methyl-2-oxazoline). Potentiometric titration of the alkyl-PEI shows the influence of the alkyl chain and the degree of polymerization on the titration curves and hence on the polymer conformation. Karl Fischer titration has been used to determine the water content in the polymers. Subsequent X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) measurements prove the existence of different hydration states of the PEI even under dry storage conditions. Upon cooling from hot aqueous Solutions, hydrogels form. The gelation concentration decreases with increasing degree of polymerization of the PEI segment. Scanning electron microscopy (SEM and cryo-SEM) of the hydrogels reveal an alkyl-PEI fibrous network composed of fan-like units. DSC shows that the percentages of bound and free water in the hydrogels depend on the concentration of polar amino groups. Y1 - 2009 UR - http://pubs.acs.org/journal/langd5 U6 - https://doi.org/10.1021/La9013569 SN - 0743-7463 ER - TY - GEN A1 - Figueroa Campos, Gustavo A. A1 - Perez, Jeffrey Paulo H. A1 - Block, Inga A1 - Tchewonpi Sagu, Sorel A1 - Saravia Celis, Pedro A1 - Taubert, Andreas A1 - Rawel, Harshadrai Manilal T1 - Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost adsorbent with prospective to compete with commercial carbons. So far, very few studies have referred to the valorization of coffee parchment into activated carbon. Moreover, low-cost and efficient activation methods need to be more investigated. The aim of this work was to prepare activated carbon from spent coffee grounds and parchment, and to assess their adsorption performance. The co-calcination processing with calcium carbonate was used to prepare the activated carbons, and their adsorption capacity for organic acids, phenolic compounds and proteins was evaluated. Both spent coffee grounds and parchment showed yields after the calcination and washing treatments of around 9.0%. The adsorption of lactic acid was found to be optimal at pH 2. The maximum adsorption capacity of lactic acid with standard commercial granular activated carbon was 73.78 mg/g, while the values of 32.33 and 14.73 mg/g were registered for the parchment and spent coffee grounds activated carbons, respectively. The Langmuir isotherm showed that lactic acid was adsorbed as a monolayer and distributed homogeneously on the surface. Around 50% of total phenols and protein content from coffee wastewater were adsorbed after treatment with the prepared activated carbons, while 44, 43, and up to 84% of hydrophobic compounds were removed using parchment, spent coffee grounds and commercial activated carbon, respectively; the adsorption efficiencies of hydrophilic compounds ranged between 13 and 48%. Finally, these results illustrate the potential valorization of coffee by-products parchment and spent coffee grounds into activated carbon and their use as low-cost adsorbent for the removal of organic compounds from aqueous solutions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1158 KW - coffee by-products KW - spent coffee grounds KW - parchment KW - valorization KW - calcination KW - activated carbon KW - organic compounds adsorption Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-521914 SN - 1866-8372 IS - 8 ER - TY - JOUR A1 - Figueroa Campos, Gustavo Adolfo A1 - Perez, Jeffrey Paulo H. A1 - Block, Inga A1 - Sagu Tchewonpi, Sorel A1 - Saravia Celis, Pedro A1 - Taubert, Andreas A1 - Rawel, Harshadrai Manilal T1 - Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency JF - Processes : open access journal N2 - The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost adsorbent with prospective to compete with commercial carbons. So far, very few studies have referred to the valorization of coffee parchment into activated carbon. Moreover, low-cost and efficient activation methods need to be more investigated. The aim of this work was to prepare activated carbon from spent coffee grounds and parchment, and to assess their adsorption performance. The co-calcination processing with calcium carbonate was used to prepare the activated carbons, and their adsorption capacity for organic acids, phenolic compounds and proteins was evaluated. Both spent coffee grounds and parchment showed yields after the calcination and washing treatments of around 9.0%. The adsorption of lactic acid was found to be optimal at pH 2. The maximum adsorption capacity of lactic acid with standard commercial granular activated carbon was 73.78 mg/g, while the values of 32.33 and 14.73 mg/g were registered for the parchment and spent coffee grounds activated carbons, respectively. The Langmuir isotherm showed that lactic acid was adsorbed as a monolayer and distributed homogeneously on the surface. Around 50% of total phenols and protein content from coffee wastewater were adsorbed after treatment with the prepared activated carbons, while 44, 43, and up to 84% of hydrophobic compounds were removed using parchment, spent coffee grounds and commercial activated carbon, respectively; the adsorption efficiencies of hydrophilic compounds ranged between 13 and 48%. Finally, these results illustrate the potential valorization of coffee by-products parchment and spent coffee grounds into activated carbon and their use as low-cost adsorbent for the removal of organic compounds from aqueous solutions. KW - coffee by-products KW - spent coffee grounds KW - parchment KW - valorization KW - calcination KW - activated carbon KW - organic compounds adsorption Y1 - 2021 U6 - https://doi.org/10.3390/pr9081396 SN - 2227-9717 VL - 9 IS - 8 PB - MDPI CY - Basel 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 - GEN A1 - Jeličić, Aleksandra A1 - Friedrich, Alwin A1 - Jeremić, Katarina A1 - Siekmeyer, Gerd A1 - Taubert, Andreas T1 - Polymer hydrogel/polybutadiene/iron oxide nanoparticle hybrid actuators for the characterization of NiTi implants N2 - One of the main issues with the use of nickel titanium alloy (NiTi) implants in cardiovascular implants (stents) is that these devices must be of very high quality in order to avoid subsequent operations due to failing stents. For small stents with diameters below ca. 2 mm, however, stent characterization is not straightforward. One of the main problems is that there are virtually no methods to characterize the interior of the NiTi tubes used for fabrication of these tiny stents. The current paper reports on a robust hybrid actuator for the characterization of NiTi tubes prior to stent fabrication. The method is based on a polymer/hydrogel/magnetic nanoparticle hybrid material and allows for the determination of the inner diameter at virtually all places in the raw NiTi tubes. Knowledge of the inner structure of the raw NiTi tubes is crucial to avoid regions that are not hollow or regions that are likely to fail due to defects inside the raw tube. The actuator enables close contact of a magnetic polymer film with the inner NiTi tube surface. The magnetic signal can be detected from outside and be used for a direct mapping of the tube interior. As a result, it is possible to detect critical regions prior to expensive and slow stent fabrication processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 161 KW - NiTi KW - inner surface KW - hydrogel KW - polybutadiene KW - magnetic nanoparticles Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-48589 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 - 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 - GEN 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 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 208 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-85299 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 - 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 - 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 - Graf, Philipp A1 - Mantion, Alexandre A1 - Foelske, Annette A1 - Shkilnyy, Andriy A1 - MaÜic, Admir A1 - Thuenemann, Andreas F. A1 - Taubert, Andreas T1 - Peptide-coated silver nanoparticles : synthesis, surface chemistry, and pH-triggered, reversible assembly into particle assemblies N2 - Simple tripeptides are scaffolds for the synthesis and further assembly of peptide/silver nanoparticle composites. Herein, we further explore peptide-con trolled silver nanoparticle assembly processes. Silver nanoparticles with a pH-responsive peptide coating have been synthesized by using a one-step precipitation/coating route. The nature of the peptide/silver interaction and the effect of the peptide oil the formation of the silver particles have been studied via UV/Vis, X-ray photoelectron, and surface-enhanced Raman spectroscopies as well as through electron microscopy, small angle X-ray scattering and powder Xray diffraction with Rietveld refinement. The particles reversibly form aggregates of different sizes in aqueous solution. The state of aggregation call be controlled by the solution pH value. At low pH values, individual particles are present. At neutral pH values, small clusters form and at high pH values, large precipitates are observed. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/26293/ U6 - https://doi.org/10.1002/chem.200802329 SN - 0947-6539 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 -