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 -