@article{UgwujaAdelowoOgunlajaetal.2019, author = {Ugwuja, Chidinma G. and Adelowo, Olawale O. and Ogunlaja, Aemere and Omorogie, Martins O. and Olukanni, Olumide D. and Ikhimiukor, Odion O. and Iermak, Ievgeniia and Kolawole, Gabriel A. and G{\"u}nter, Christina and Taubert, Andreas and Bodede, Olusola and Moodley, Roshila and Inada, Natalia M. and Camargo, Andrea S.S. de and Unuabonah, Emmanuel Iyayi}, title = {Visible-Light-Mediated Photodynamic Water Disinfection @ Bimetallic-Doped Hybrid Clay Nanocomposites}, series = {ACS applied materials \& interfaces}, volume = {11}, journal = {ACS applied materials \& interfaces}, number = {28}, publisher = {American Chemical Society}, address = {Washington, DC}, issn = {1944-8244}, doi = {10.1021/acsami.9b01212}, pages = {25483 -- 25494}, year = {2019}, abstract = {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.}, language = {en} } @article{ShkilnyyGraefHiebletal.2009, author = {Shkilnyy, Andriy and Gr{\"a}f, Ralph and Hiebl, Bernhard and Neffe, Axel T. and Friedrich, Alwin and Hartmann, Juergen and Taubert, Andreas}, title = {Unprecedented, low cytotoxicity of spongelike calcium phosphate/poly(ethylene imine) hydrogel composites}, issn = {1616-5187}, doi = {10.1002/mabi.200800266}, year = {2009}, abstract = {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.}, language = {en} } @article{LerouxRabuSommerdijketal.2015, author = {Leroux, Fabrice and Rabu, Pierre and Sommerdijk, Nico A. J. M. and Taubert, Andreas}, title = {Two-Dimensional Hybrid Materials: Transferring Technology from Biology to Society}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, number = {7}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201500153}, pages = {1089 -- 1095}, year = {2015}, abstract = {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.}, language = {en} } @article{XieJelicicWangetal.2010, author = {Xie, Zai-Lai and Jelicic, Aleksandra and Wang, Feipeng and Rabu, Pierre and Friedrich, Alwin and Beuermann, Sabine and Taubert, Andreas}, title = {Transparent, flexible, and paramagnetic ionogels based on PMMA and the iron-based ionic liquid 1-butyl-3- methylimidazolium tetrachloroferrate(III) [Bmim][FeCl4]}, issn = {0959-9428}, doi = {10.1039/C0jm01733g}, year = {2010}, abstract = {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.}, language = {en} } @article{DraudeGallaPelsteretal.2013, author = {Draude, F. and Galla, S. and Pelster, Axel and Tentschert, J. and Jungnickel, H. and Haase, Alfred and Mantion, Alexandre and Thuenemann, Andreas F. and Taubert, Andreas and Luch, A. and Arlinghaus, H. F.}, title = {ToF-SIMS and Laser-SNMS analysis of macrophages after exposure to silver nanoparticles}, series = {Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films}, volume = {45}, journal = {Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films}, number = {1}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0142-2421}, doi = {10.1002/sia.4902}, pages = {286 -- 289}, year = {2013}, abstract = {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.}, language = {en} } @article{TentschertDraudeJungnickeletal.2013, author = {Tentschert, J. and Draude, F. and Jungnickel, H. and Haase, A. and Mantion, Alexandre and Galla, S. and Thuenemann, Andreas F. and Taubert, Andreas and Luch, A. and Arlinghaus, H. F.}, title = {TOF-SIMS analysis of cell membrane changes in functional impaired human macrophages upon nanosilver treatment}, series = {Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films}, volume = {45}, journal = {Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films}, number = {1}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0142-2421}, doi = {10.1002/sia.5155}, pages = {483 -- 485}, year = {2013}, abstract = {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.}, language = {en} } @article{XieTaubert2011, author = {Xie, Zai-Lai and Taubert, Andreas}, title = {Thermomorphic behavior of the ionic liquids [C(4)mim][FeCl4] and [C(12)mim][FeCl4]}, series = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, volume = {12}, journal = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, number = {2}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4235}, doi = {10.1002/cphc.201000808}, pages = {364 -- 368}, year = {2011}, abstract = {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.}, language = {en} } @article{LehmannFranzToebbensetal.2019, author = {Lehmann, Frederike and Franz, Alexandra and Toebbens, Daniel M. and Levcenco, Sergej and Unold, Thomas and Taubert, Andreas and Schorr, Susan}, title = {The phase diagram of a mixed halide (Br, I) hybrid perovskite obtained by synchrotron X-ray diffraction}, series = {RSC Advances}, volume = {9}, journal = {RSC Advances}, number = {20}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c8ra09398a}, pages = {11151 -- 11159}, year = {2019}, abstract = {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.}, language = {en} } @article{BalischewskiBhattacharyyaSperlichetal.2022, author = {Balischewski, Christian and Bhattacharyya, Biswajit and Sperlich, Eric and G{\"u}nter, Christina and Beqiraj, Alkit and Klamroth, Tillmann and Behrens, Karsten and Mies, Stefan and Kelling, Alexandra and Lubahn, Susanne and Holtzheimer, Lea and Nitschke, Anne and Taubert, Andreas}, title = {Tetrahalidometallate(II) ionic liquids with more than one metal}, series = {Chemistry - a European journal}, volume = {28}, journal = {Chemistry - a European journal}, number = {64}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-3765}, doi = {10.1002/chem.202201068}, pages = {13}, year = {2022}, abstract = {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.}, language = {en} } @article{FarraThielWinteretal.2011, author = {Farra, Ramzi and Thiel, Kerstin and Winter, Alette and Klamroth, Tillmann and Poeppl, Andreas and Kelling, Alexandra and Schilde, Uwe and Taubert, Andreas and Strauch, Peter}, title = {Tetrahalidocuprates(II)-structure and EPR spectroscopy Part 1: Tetrabromidocuprates(II)}, series = {New journal of chemistry}, volume = {35}, journal = {New journal of chemistry}, number = {12}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1144-0546}, doi = {10.1039/c1nj20271e}, pages = {2793 -- 2803}, year = {2011}, abstract = {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.}, language = {en} }