@article{WinterThielZabeletal.2014, author = {Winter, Alette and Thiel, Kerstin and Zabel, Andre 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 2: tetrachloridocuprates(II)}, series = {New journal of chemistry}, volume = {38}, journal = {New journal of chemistry}, number = {3}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1144-0546}, doi = {10.1039/c3nj01039b}, pages = {1019 -- 1030}, year = {2014}, abstract = {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.}, language = {en} } @article{PanSarhanKochovskietal.2022, author = {Pan, Xuefeng and Sarhan, Radwan Mohamed and Kochovski, Zdravko and Chen, Guosong and Taubert, Andreas and Mei, Shilin and Lu, Yan}, title = {Template synthesis of dual-functional porous MoS2 nanoparticles with photothermal conversion and catalytic properties}, series = {Nanoscale}, volume = {14}, journal = {Nanoscale}, number = {18}, publisher = {RSC Publ. (Royal Society of Chemistry)}, address = {Cambridge}, issn = {2040-3372}, doi = {10.1039/d2nr01040b}, pages = {6888 -- 6901}, year = {2022}, abstract = {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.}, language = {en} } @article{GoebelHesemannWeberetal.2009, author = {Goebel, Ronald and Hesemann, Peter and Weber, Jens and Moeller, El{\´e}onore and Friedrich, Alwin and Beuermann, Sabine and Taubert, Andreas}, title = {Surprisingly high, bulk liquid-like mobility of silica-confined ionic liquids}, issn = {1463-9076}, doi = {10.1039/B821833a}, year = {2009}, abstract = {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.}, language = {en} } @article{SchweizerSchusterJungingeretal.2010, author = {Schweizer, S. and Schuster, T. and Junginger, Matthias and Siekmeyer, Gerd and Taubert, Andreas}, title = {Surface modification of ickel/Titanium Alloy and Titanium Surfaces via a Polyelectrolyte Multilayer/Calcium Phosphate Hybrid Coating}, issn = {1438-7492}, doi = {10.1002/mame.200900347}, year = {2010}, abstract = {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).}, language = {en} } @article{SchneiderFritzschePuciulMalinowskaetal.2020, author = {Schneider, Matthias and Fritzsche, Nora and Puciul-Malinowska, Agnieszka and Balis, Andrzej and Mostafa, Amr and Bald, Ilko and Zapotoczny, Szczepan and Taubert, Andreas}, title = {Surface etching of 3D printed poly(lactic acid) with NaOH: a systematic approach}, series = {Polymers}, volume = {12}, journal = {Polymers}, number = {8}, publisher = {MDPI}, address = {Basel}, pages = {16}, year = {2020}, abstract = {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.}, language = {en} } @article{SchneiderFritzschePuciulMalinowskaetal.2020, author = {Schneider, Matthias and Fritzsche, Nora and Puciul-Malinowska, Agnieszka and Baliś, Andrzej and Mostafa, Amr and Bald, Ilko and Zapotoczny, Szczepan and Taubert, Andreas}, title = {Surface etching of 3D printed poly(lactic acid) with NaOH}, series = {Polymers}, volume = {12}, journal = {Polymers}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2073-4360}, doi = {10.3390/polym12081711}, pages = {16}, year = {2020}, abstract = {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.}, language = {en} } @article{IhlenburgMaiThuenemannetal.2021, author = {Ihlenburg, Ramona and Mai, Tobias and Th{\"u}nemann, Andreas F. and Baerenwald, Ruth and Saalw{\"a}chter, Kay and Koetz, Joachim and Taubert, Andreas}, title = {Sulfobetaine hydrogels with a complex multilength-scale hierarchical structure}, series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, volume = {125}, journal = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, number = {13}, publisher = {American Chemical Society}, address = {Washington}, issn = {1520-6106}, doi = {10.1021/acs.jpcb.0c10601}, pages = {3398 -- 3408}, year = {2021}, abstract = {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.}, language = {en} } @article{IhlenburgLehnenKoetzetal.2021, author = {Ihlenburg, Ramona and Lehnen, Anne-Catherine and Koetz, Joachim and Taubert, Andreas}, title = {Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions}, series = {Polymers / Molecular Diversity Preservation International}, volume = {13}, journal = {Polymers / Molecular Diversity Preservation International}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2073-4360}, doi = {10.3390/polym13020208}, pages = {11}, year = {2021}, abstract = {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.}, language = {en} } @article{ZehbeLangeTaubert2019, author = {Zehbe, Kerstin and Lange, Alyna and Taubert, Andreas}, title = {Stereolithography Provides Access to 3D Printed lonogels with High Ionic Conductivity}, series = {Energy Fuels}, volume = {33}, journal = {Energy Fuels}, number = {12}, publisher = {American Chemical Society}, address = {Washington}, issn = {0887-0624}, doi = {10.1021/acs.energyfuels.9b03379}, pages = {12885 -- 12893}, year = {2019}, abstract = {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.}, language = {en} } @article{HeroldAignerGrilletal.2019, author = {Herold, Heike M. and Aigner, Tamara Bernadette and Grill, Carolin E. and Kr{\"u}ger, Stefanie and Taubert, Andreas and Scheibel, Thomas R.}, title = {SpiderMAEn}, series = {Bioinspired, Biomimetic and Nanobiomaterials}, volume = {8}, journal = {Bioinspired, Biomimetic and Nanobiomaterials}, number = {1}, publisher = {ICE Publishing}, address = {Westminister}, issn = {2045-9858}, doi = {10.1680/jbibn.18.00007}, pages = {99 -- 108}, year = {2019}, abstract = {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.}, language = {en} } @article{CasseShkilnyyLindersetal.2012, author = {Casse, Olivier and Shkilnyy, Andriy and Linders, J{\"u}rgen and Mayer, Christian and H{\"a}ussinger, Daniel and V{\"o}lkel, Antje and Th{\"u}nemann, Andreas F. and Dimova, Rumiana and C{\"o}lfen, Helmut and Meier, Wolfgang P. and Schlaad, Helmut and Taubert, Andreas}, title = {Solution behavior of double-hydrophilic block copolymers in dilute aqueous solution}, series = {Macromolecules : a publication of the American Chemical Society}, volume = {45}, journal = {Macromolecules : a publication of the American Chemical Society}, number = {11}, publisher = {American Chemical Society}, address = {Washington}, issn = {0024-9297}, doi = {10.1021/ma300621g}, pages = {4772 -- 4777}, year = {2012}, abstract = {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.}, language = {en} } @article{KindPlamperGoebeletal.2009, author = {Kind, Lucy and Plamper, Felix A. and Goebel, Ronald and Mantion, Alexandre and Mueller, Axel H. E. and Pieles, Uwe and Taubert, Andreas and Meier, Wolfgang P.}, title = {Silsesquioxane/polyamine nanoparticle-templated formation of star- or raspberry-like silica nanoparticles}, issn = {0743-7463}, doi = {10.1021/La900229n}, year = {2009}, abstract = {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.}, language = {en} } @article{GrafMantionHaaseetal.2011, author = {Graf, Philipp and Mantion, Alexandre and Haase, Andrea and Thuenemann, Andreas F. and Masic, Admir and Meier, Wolfgang P. and Luch, Andreas and Taubert, Andreas}, title = {Silicification of peptide-coated silver nanoparticles-A biomimetic soft chemistry approach toward chiral hybrid core-shell materials}, series = {ACS nano}, volume = {5}, journal = {ACS nano}, number = {2}, publisher = {American Chemical Society}, address = {Washington}, issn = {1936-0851}, doi = {10.1021/nn102969p}, pages = {820 -- 833}, year = {2011}, abstract = {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.}, language = {en} } @article{DelahayeGoebelLoebbickeetal.2012, author = {Delahaye, Emilie and Goebel, Ronald and Loebbicke, Ruben and Guillot, Regis and Sieber, Christoph and Taubert, Andreas}, title = {Silica ionogels for proton transport}, series = {Journal of materials chemistry}, volume = {22}, journal = {Journal of materials chemistry}, number = {33}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {0959-9428}, doi = {10.1039/c2jm00037g}, pages = {17140 -- 17146}, year = {2012}, abstract = {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.}, language = {en} } @article{UnuabonahOluOwolabiTaubertetal.2013, author = {Unuabonah, Emmanuel Iyayi and Olu-Owolabi, Bamidele I. and Taubert, Andreas and Omolehin, Elizabeth B. and Adebowale, Kayode O.}, title = {SAPK a novel composite resin for water treatment with very high Zn2+, Cd2+, and Pb2+ adsorption capacity}, series = {Industrial \& engineering chemistry research}, volume = {52}, journal = {Industrial \& engineering chemistry research}, number = {2}, publisher = {American Chemical Society}, address = {Washington}, issn = {0888-5885}, doi = {10.1021/ie3024577}, pages = {578 -- 585}, year = {2013}, abstract = {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+.}, language = {en} } @article{KirchheckerTroegerMuellerBakeetal.2015, author = {Kirchhecker, Sarah and Tr{\"o}ger-M{\"u}ller, Steffen and Bake, Sebastian and Antonietti, Markus and Taubert, Andreas and Esposito, Davido}, title = {Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions}, series = {Green chemistry}, volume = {8}, journal = {Green chemistry}, number = {17}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9262}, doi = {10.1039/c5gc00913h}, pages = {4151 -- 4156}, year = {2015}, abstract = {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.}, language = {en} } @article{KirchheckerTroegerMuellerBakeetal.2015, author = {Kirchhecker, Sarah and Tr{\"o}ger-M{\"u}ller, Steffen and Bake, Sebastian and Antonietti, Markus and Taubert, Andreas and Esposito, Davide}, title = {Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions}, series = {Green chemistry : an international journal and green chemistry resource}, volume = {17}, journal = {Green chemistry : an international journal and green chemistry resource}, number = {8}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9262}, doi = {10.1039/c5gc00913h}, pages = {4151 -- 4156}, year = {2015}, abstract = {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.}, language = {en} } @article{NavarroShkilnyyTierschetal.2009, author = {Navarro, Salvador and Shkilnyy, Andriy and Tiersch, Brigitte and Taubert, Andreas and Menzel, Henning}, title = {Preparation, characterization, and thermal gelation of amphiphilic alkyl-poly(ethyleneimine)}, issn = {0743-7463}, doi = {10.1021/La9013569}, year = {2009}, abstract = {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.}, language = {en} } @article{FigueroaCamposPerezBlocketal.2021, author = {Figueroa Campos, Gustavo Adolfo and Perez, Jeffrey Paulo H. and Block, Inga and Sagu Tchewonpi, Sorel and Saravia Celis, Pedro and Taubert, Andreas and Rawel, Harshadrai Manilal}, title = {Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency}, series = {Processes : open access journal}, volume = {9}, journal = {Processes : open access journal}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2227-9717}, doi = {10.3390/pr9081396}, pages = {18}, year = {2021}, abstract = {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.}, language = {en} } @article{ZhangWillaSunetal.2017, author = {Zhang, Weiyi and Willa, Christoph and Sun, Jian-Ke and Guterman, Ryan and Taubert, Andreas and Yuan, Jiayin}, title = {Polytriazolium poly(ionic liquid) bearing triiodide anions: Synthesis, basic properties and electrochemical behaviors}, series = {Polymer : the international journal for the science and technology of polymers}, volume = {124}, journal = {Polymer : the international journal for the science and technology of polymers}, publisher = {Elsevier}, address = {Oxford}, issn = {0032-3861}, doi = {10.1016/j.polymer.2017.07.059}, pages = {246 -- 251}, year = {2017}, abstract = {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.}, language = {en} } @article{LoebbickeChananaSchlaadetal.2011, author = {L{\"o}bbicke, Ruben and Chanana, Munish and Schlaad, Helmut and Pilz-Allen, Christine and G{\"u}nter, Christina and M{\"o}hwald, Helmuth and Taubert, Andreas}, title = {Polymer Brush Controlled Bioinspired Calcium Phosphate Mineralization and Bone Cell Growth}, series = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, volume = {12}, journal = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, number = {10}, publisher = {American Chemical Society}, address = {Washington}, issn = {1525-7797}, doi = {10.1021/bm200991b}, pages = {3753 -- 3760}, year = {2011}, abstract = {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.}, language = {en} } @article{MaiBoyeYuanetal.2015, author = {Mai, Tobias and Boye, Susanne and Yuan, Jiayin and V{\"o}lkel, Antje and Gr{\"a}wert, Marlies and G{\"u}nter, Christina and Lederer, Albena and Taubert, Andreas}, title = {Poly(ethylene oxide)-based block copolymers with very high molecular weights for biomimetic calcium phosphate mineralization}, series = {RSC Advances : an international journal to further the chemical sciences}, journal = {RSC Advances : an international journal to further the chemical sciences}, number = {5}, publisher = {RSC Publishing}, address = {London}, issn = {2046-2069}, doi = {10.1039/c5ra20035k}, pages = {103494 -- 103505}, year = {2015}, abstract = {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.}, language = {en} } @article{MaiBoyeYuanetal.2015, author = {Mai, Tobias and Boye, Susanne and Yuan, Jiayin and Voelkel, Antje and Graewert, Marlies and G{\"u}nter, Christina and Lederer, Albena and Taubert, Andreas}, title = {Poly(ethylene oxide)-based block copolymers with very high molecular weights for biomimetic calcium phosphate mineralization}, series = {RSC Advances}, volume = {5}, journal = {RSC Advances}, number = {125}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c5ra20035k}, pages = {103494 -- 103505}, year = {2015}, abstract = {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.}, language = {en} } @article{MaiRakhmatullinaBleeketal.2014, author = {Mai, Tobias and Rakhmatullina, Ekaterina and Bleek, Katrin and Boye, Susanne and Yuan, Jiayin and Voelkel, Antje and Graewert, Marlies and Cheaib, Zeinab and Eick, Sigrun and G{\"u}nter, Christina and Lederer, Albena and Lussi, Adrian and Taubert, Andreas}, title = {Poly(ethylene oxide)-b-poly(3-sulfopropyl methacrylate) block copolymers for calcium phosphate mineralization and biofilm inhibition}, series = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, volume = {15}, journal = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, number = {11}, publisher = {American Chemical Society}, address = {Washington}, issn = {1525-7797}, doi = {10.1021/bm500888q}, pages = {3901 -- 3914}, year = {2014}, abstract = {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.}, language = {en} } @article{SiTaubertMantionetal.2012, author = {Si, Satyabrata and Taubert, Andreas and Mantion, Alexandre and Rogez, Guillaume and Rabu, Pierre}, title = {Peptide-intercalated layered metal hydroxides effect of peptide chain length and side chain functionality on structural, optical and magnetic properties}, series = {Chemical science}, volume = {3}, journal = {Chemical science}, number = {6}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2041-6520}, doi = {10.1039/c2sc01087a}, pages = {1945 -- 1957}, year = {2012}, abstract = {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.}, language = {en} } @article{GrafMantionFoelskeetal.2009, author = {Graf, Philipp and Mantion, Alexandre and Foelske, Annette and Shkilnyy, Andriy and Ma{\"U}ic, Admir and Thuenemann, Andreas F. and Taubert, Andreas}, title = {Peptide-coated silver nanoparticles : synthesis, surface chemistry, and pH-triggered, reversible assembly into particle assemblies}, issn = {0947-6539}, doi = {10.1002/chem.200802329}, year = {2009}, abstract = {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.}, language = {en} } @article{ThielKlamrothStrauchetal.2011, author = {Thiel, Kerstin and Klamroth, Tillmann and Strauch, Peter and Taubert, Andreas}, title = {On the interaction of ascorbic acid and the tetrachlorocuprate ion [CuCl4](2-) in CuCl nanoplatelet formation from an ionic liquid precursor (ILP)}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {13}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {30}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/c1cp20648f}, pages = {13537 -- 13543}, year = {2011}, abstract = {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.}, language = {en} } @article{AyiKhareStrauchetal.2010, author = {Ayi, Ayi A. and Khare, Varsha and Strauch, Peter and Girard, J{\`e}r{\^o}me and Fromm, Katharina M. and Taubert, Andreas}, title = {On the chemical synthesis of titanium nanoparticles from ionic liquids}, issn = {0026-9247}, doi = {10.1007/s00706-010-0403-4}, year = {2010}, abstract = {We report on attempts towards the synthesis of titanium nanoparticles using a wet chemical approach in imidazolium-based ionic liquids (ILs) under reducing conditions. Transmission electron microscopy finds nanoparticles in all cases. UV/Vis spectroscopy confirms the nanoparticulate nature of the precipitate, as in all cases an absorption band between ca. 280 and 300 nm is visible. IR spectroscopy shows that even after extensive washing and drying, some IL remains adsorbed on the nanoparticles. Raman spectroscopy suggests the formation of anatase nanoparticles, but X-ray diffraction reveals that, possibly, amorphous titania forms or that the nanoparticles are so small that a clear structure assignment is not possible. The report thus shows that (possibly amorphous) titanium oxides even form under reducing conditions and that the chemical synthesis of titanium nanoparticles in ILs remains elusive.}, language = {en} } @article{UnuabonahKolawoleAgunbiadeetal.2017, author = {Unuabonah, Emmanuel Iyayi and Kolawole, Matthew O. and Agunbiade, Foluso O. and Omorogie, Martins O. and Koko, Daniel T. and Ugwuja, Chidinma G. and Ugege, Leonard E. and Oyejide, Nicholas E. and G{\"u}nter, Christina and Taubert, Andreas}, title = {Novel metal-doped bacteriostatic hybrid clay composites for point-of-use disinfection of water}, series = {Journal of Environmental Chemical Engineering}, volume = {5}, journal = {Journal of Environmental Chemical Engineering}, publisher = {Elsevier}, address = {Oxford}, issn = {2213-3437}, doi = {10.1016/j.jece.2017.04.017}, pages = {2128 -- 2141}, year = {2017}, abstract = {This study reports the facile microwave-assisted thermal preparation of novel metal-doped hybrid clay composite adsorbents consisting of Kaolinite clay, Carica papaya seeds and/or plantain peels (Musa paradisiaca) and ZnCl2. Fourier Transformed IR spectroscopy, X-ray diffraction, Scanning Electron Microscopy and Brunauer-Emmett-Teller (BET) analysis are employed to characterize these composite adsorbents. The physicochemical analysis of these composites suggests that they act as bacteriostatic rather than bacteriacidal agents. This bacterostactic action is induced by the ZnO phase in the composites whose amount correlates with the efficacy of the composite. The composite prepared with papaya seeds (PS-HYCA) provides the best disinfection efficacy (when compared with composite prepared with Musa paradisiaca peels-PP-HYCA) against gram-negative enteric bacteria with a breakthrough time of 400 and 700 min for the removal of 1.5 x10(6) cfu/mL S. typhi and V. cholerae from water respectively. At 10(3) cfu/mL of each bacterium in solution, 2 g of both composite adsorbents kept the levels the bacteria in effluent solutions at zero for up to 24 h. Steam regeneration of 2 g of bacteria-loaded Carica papaya prepared composite adsorbent shows a loss of ca. 31\% of its capacity even after the 3rd regeneration cycle of 25 h of service time. The composite adsorbent prepared with Carica papaya seeds will be useful for developing simple point-of-use water treatment systems for water disinfection application. This composite adsorbent is comparatively of good performance and shows relatively long hydraulic contact times and is expected to minimize energy intensive traditional treatment processes.}, language = {en} } @article{UnuabonahNoeskeWeberetal.2019, author = {Unuabonah, Emmanuel Iyayi and N{\"o}ske, Robert and Weber, Jens and G{\"u}nter, Christina and Taubert, Andreas}, title = {New micro/mesoporous nanocomposite material from low-cost sources for the efficient removal of aromatic and pathogenic pollutants from water}, series = {Beilstein journal of nanotechnology}, volume = {10}, journal = {Beilstein journal of nanotechnology}, publisher = {Beilstein-Institut zur F{\"o}rderung der Chemischen Wissenschaften}, address = {Frankfurt, Main}, issn = {2190-4286}, doi = {10.3762/bjnano.10.11}, pages = {119 -- 131}, year = {2019}, abstract = {A new micro/mesoporous hybrid clay nanocomposite prepared from kaolinite clay, Carica papaya seeds, and ZnCl2 via calcination in an inert atmosphere is presented. Regardless of the synthesis temperature, the specific surface area of the nanocomposite material is between approximate to 150 and 300 m(2)/g. The material contains both micro- and mesopores in roughly equal amounts. X-ray diffraction, infrared spectroscopy, and solid-state nuclear magnetic resonance spectroscopy suggest the formation of several new bonds in the materials upon reaction of the precursors, thus confirming the formation of a new hybrid material. Thermogravimetric analysis/differential thermal analysis and elemental analysis confirm the presence of carbonaceous matter. The new composite is stable up to 900 degrees C and is an efficient adsorbent for the removal of a water micropollutant, 4-nitrophenol, and a pathogen, E. coli, from an aqueous medium, suggesting applications in water remediation are feasible.}, language = {en} } @article{BhattacharyyaBalischewskiSperlichetal.2023, author = {Bhattacharyya, Biswajit and Balischewski, Christian and Sperlich, Eric and G{\"u}nter, Christina and Mies, Stefan and Kelling, Alexandra and Taubert, Andreas}, title = {N-Butyl Pyridinium Diiodido Argentate(I)}, series = {Advanced materials interfaces}, volume = {10}, journal = {Advanced materials interfaces}, number = {12}, publisher = {Wiley}, address = {Hoboken}, issn = {2196-7350}, doi = {10.1002/admi.202202363}, pages = {7}, year = {2023}, abstract = {A new solid-state material, N-butyl pyridinium diiodido argentate(I), is synthesized using a simple and effective one-pot approach. In the solid state, the compound exhibits 1D ([AgI2](-))(n) chains that are stabilized by the N-butyl pyridinium cation. The 1D structure is further manifested by the formation of long, needle-like crystals, as revealed from electron microscopy. As the general composition is derived from metal halide-based ionic liquids, the compound has a low melting point of 100-101 degrees C, as confirmed by differential scanning calorimetry. Most importantly, the compound has a conductivity of 10(-6) S cm(-1) at room temperature. At higher temperatures the conductivity increases and reaches to 10(-4 )S cm(-1) at 70 degrees C. In contrast to AgI, however, the current material has a highly anisotropic 1D arrangement of the ionic domains. This provides direct and tuneable access to fast and anisotropic ionic conduction. The material is thus a significant step forward beyond current ion conductors and a highly promising prototype for the rational design of highly conductive ionic solid-state conductors for battery or solar cell applications.}, language = {en} } @article{GoebelHesemannFriedrichetal.2014, author = {Goebel, Ronald and Hesemann, Peter and Friedrich, Alwin and Rothe, Regina and Schlaad, Helmut and Taubert, Andreas}, title = {Modular thiol-ene chemistry approach towards mesoporous silica monoliths with organically modified pore walls}, series = {Chemistry - a European journal}, volume = {20}, journal = {Chemistry - a European journal}, number = {52}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201403982}, pages = {17579 -- 17589}, year = {2014}, abstract = {The surface modification of mesoporous silica monoliths through thiol-ene chemistry is reported. First, mesoporous silica monoliths with vinyl, allyl, and thiol groups were synthesized through a sol-gel hydrolysis-poly-condensation reaction from tetramethyl orthosilicate (TMOS) and vinyltriethoxysilane, allyltriethoxysilane, and (3-mercaptopropyl) trimethoxysilane, respectively. By variation of the molar ratio of the comonomers TMOS and functional silane, mesoporous silica objects containing different amounts of vinyl, allyl, and thiol groups were obtained. These intermediates can subsequently be derivatized through radical photoaddition reactions either with a thiol or an olefin, depending on the initial pore wall functionality, to yield silica monoliths with different pore-wall chemistries. Nitrogen sorption, small-angle X-ray scattering, solid-state NMR spectroscopy, elemental analysis, thermogravimetric analysis, and redox titration demonstrate that the synthetic pathway influences the morphology and pore characteristics of the resulting monoliths and also plays a significant role in the efficiency of functionalization. Moreover, the different reactivity of the vinyl and allyl groups on the pore wall affects the addition reaction, and hence, the degree of the pore-wall functionalization. This report demonstrates that thiol-ene photoaddition reactions are a versatile platform for the generation of a large variety of organically modified silica monoliths with different pore surfaces.}, language = {en} } @article{HeyneArltGessneretal.2020, author = {Heyne, Benjamin and Arlt, Kristin and Geßner, Andr{\´e} and Richter, Alexander F. and D{\"o}blinger, Markus and Feldmann, Jochen and Taubert, Andreas and Wedel, Armin}, title = {Mixed Mercaptocarboxylic Acid Shells Provide Stable Dispersions of InPZnS/ZnSe/ZnS Multishell Quantum Dots in Aqueous Media}, series = {Nanomaterials}, volume = {10}, journal = {Nanomaterials}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2079-4991}, doi = {10.3390/nano10091858}, pages = {24}, year = {2020}, abstract = {Highly luminescent indium phosphide zinc sulfide (InPZnS) quantum dots (QDs), with zinc selenide/zinc sulfide (ZnSe/ZnS) shells, were synthesized. The QDs were modified via a post-synthetic ligand exchange reaction with 3-mercaptopropionic acid (MPA) and 11-mercaptoundecanoic acid (MUA) in different MPA:MUA ratios, making this study the first investigation into the effects of mixed ligand shells on InPZnS QDs. Moreover, this article also describes an optimized method for the correlation of the QD size vs. optical absorption of the QDs. Upon ligand exchange, the QDs can be dispersed in water. Longer ligands (MUA) provide more stable dispersions than short-chain ligands. Thicker ZnSe/ZnS shells provide a better photoluminescence quantum yield (PLQY) and higher emission stability upon ligand exchange. Both the ligand exchange and the optical properties are highly reproducible between different QD batches. Before dialysis, QDs with a ZnS shell thickness of ~4.9 monolayers (ML), stabilized with a mixed MPA:MUA (mixing ratio of 1:10), showed the highest PLQY, at ~45\%. After dialysis, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with a mixed MPA:MUA and a ratio of 1:10 and 1:100, showed the highest PLQYs, of ~41\%. The dispersions were stable up to 44 days at ambient conditions and in the dark. After 44 days, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with only MUA, showed the highest PLQY, of ~34\%.}, language = {en} } @article{BehrensBalischewskiSperlichetal.2022, author = {Behrens, Karsten and Balischewski, Christian and Sperlich, Eric and Menski, Antonia Isabell and Balderas-Valadez, Ruth Fabiola and Pacholski, Claudia and G{\"u}nter, Christina and Lubahn, Susanne and Kelling, Alexandra and Taubert, Andreas}, title = {Mixed chloridometallate(ii) ionic liquids with tunable color and optical response for potential ammonia sensors}, series = {RSC Advances}, volume = {12}, journal = {RSC Advances}, publisher = {RSC}, address = {London}, issn = {2046-2069}, doi = {10.1039/d2ra05581c}, pages = {35072 -- 35082}, year = {2022}, abstract = {Eight d-metal-containing N-butylpyridinium ionic liquids (ILs) with the nominal composition (C4Py)2[Ni0.5M0.5Cl4] or (C4Py)2[Zn0.5M0.5Cl4] (M = Cu, Co, Mn, Ni, Zn; C4Py = N-butylpyridinium) were synthesized, characterized, and investigated for their optical properties. Single crystal and powder X-ray analysis shows that the compounds are isostructural to existing examples based on other d-metal ions. Inductively coupled plasma optical emission spectroscopy measurements confirm that the metal/metal ratio is around 50 : 50. UV-Vis spectroscopy shows that the optical absorption can be tuned by selection of the constituent metals. Moreover, the compounds can act as an optical sensor for the detection of gases such as ammonia as demonstrated via a simple prototype setup.}, language = {en} } @article{MarquardtXieTaubertetal.2011, author = {Marquardt, Dorothea and Xie, Zailai and Taubert, Andreas and Thomann, Ralf and Janiak, Christoph}, title = {Microwave synthesis and inherent stabilization of metal nanoparticles in 1-methyl-3-(3-carboxyethyl)-imidazolium tetrafluoroborate}, series = {Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry}, volume = {40}, journal = {Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry}, number = {33}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1477-9226}, doi = {10.1039/c1dt10795j}, pages = {8290 -- 8293}, year = {2011}, abstract = {The synthesis of Co-NPs and Mn-NPs by microwave-induced decomposition of the metal carbonyls Co-2(CO)(8) and Mn-2(CO)(10), respectively, yields smaller and better separated particles in the functionalized IL 1-methyl-3-(3-carboxyethyl)-imidazolium tetrafluoroborate [EmimCO(2)H][BF4] (1.6 +/- 0.3 nm and 4.3 +/- 1.0 nm, respectively) than in the non-functionalized IL 1-n-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4]. The particles are stable in the absence of capping ligands (surfactants) for more than six months although some variation in particle size could be observed by TEM.}, language = {en} } @article{BalischewskiChoiBehrensetal.2021, author = {Balischewski, Christian and Choi, Hyung-Seok and Behrens, Karsten and Beqiraj, Alkit and K{\"o}rzd{\"o}rfer, Thomas and Gessner, Andre and Wedel, Armin and Taubert, Andreas}, title = {Metal sulfide nanoparticle synthesis with ionic liquids state of the art and future perspectives}, series = {ChemistryOpen}, volume = {10}, journal = {ChemistryOpen}, number = {2}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2191-1363}, doi = {10.1002/open.202000357}, pages = {272 -- 295}, year = {2021}, abstract = {Metal sulfides are among the most promising materials for a wide variety of technologically relevant applications ranging from energy to environment and beyond. Incidentally, ionic liquids (ILs) have been among the top research subjects for the same applications and also for inorganic materials synthesis. As a result, the exploitation of the peculiar properties of ILs for metal sulfide synthesis could provide attractive new avenues for the generation of new, highly specific metal sulfides for numerous applications. This article therefore describes current developments in metal sulfide nano-particle synthesis as exemplified by a number of highlight examples. Moreover, the article demonstrates how ILs have been used in metal sulfide synthesis and discusses the benefits of using ILs over more traditional approaches. Finally, the article demonstrates some technological challenges and how ILs could be used to further advance the production and specific property engineering of metal sulfide nanomaterials, again based on a number of selected examples.}, language = {en} } @article{XieHuangTitiricietal.2014, author = {Xie, Zai-Lai and Huang, Xing and Titirici, Maria-Magdalena and Taubert, Andreas}, title = {Mesoporous graphite nanoflakes via ionothermal carbonization of fructose and their use in dye removal}, series = {RSC Advances}, volume = {4}, journal = {RSC Advances}, number = {70}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c4ra05146g}, pages = {37423 -- 37430}, year = {2014}, abstract = {The large-scale green synthesis of graphene-type two-dimensional materials is still challenging. Herein, we describe the ionothermal synthesis of carbon-based composites from fructose in the iron-containing ionic liquid 1-butyl-3-methylimidazolium tetrachloridoferrate(III), [Bmim][FeCl4] serving as solvent, catalyst, and template for product formation. The resulting composites consist of oligo-layer graphite nanoflakes and iron carbide particles. The mesoporosity, strong magnetic moment, and high specific surface area of the composites make them attractive for water purification with facile magnetic separation. Moreover, Fe3Cfree graphite can be obtained via acid etching, providing access to fairly large amounts of graphite material. The current approach is versatile and scalable, and thus opens the door to ionothermal synthesis towards the larger-scale synthesis of materials that are, although not made via a sustainable process, useful for water treatment such as the removal of organic molecules.}, language = {en} } @article{ZiolkowskiBleekTwamleyetal.2012, author = {Ziolkowski, Bartosz and Bleek, Katrin and Twamley, Brendan and Fraser, Kevin J. and Byrne, Robert and Diamond, Dermot and Taubert, Andreas}, title = {Magnetic ionogels (MagIGs) based on iron oxide nanoparticles, poly(N-isopropylacrylamide), and the ionic liquid trihexyl(tetradecyl)phosphonium dicyanamide}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, number = {32}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201200597}, pages = {5245 -- 5251}, year = {2012}, abstract = {Magnetic ionogels (MagIGs) were prepared from organosilane-coated iron oxide nanoparticles, N-isopropylacrylamide, and the ionic liquid trihexyl(tetradecyl)phosphonium dicyanamide. The ionogels prepared with the silane-modified nanoparticles are more homogeneous than ionogels prepared with unmodified magnetite particles. The silane-modified particles are immobilized in the ionogel and are resistant tonanoparticle leaching. The modified particles also render the ionogels mechanically more stable than the ionogels synthesized with unmodified nanoparticles. The ionogels respond to external permanent magnets and are therefore prototypes of a new soft magnetic actuator.}, language = {en} } @article{TaoLiuWuetal.2020, author = {Tao, Lumi and Liu, Yuchuan and Wu, Dan and Wei, Qiao-Hua and Taubert, Andreas and Xie, Zailai}, title = {Luminescent Ionogels with Excellent Transparency, High Mechanical Strength, and High Conductivity}, series = {Nanomaterials}, volume = {10}, journal = {Nanomaterials}, number = {12}, publisher = {MDPI}, address = {Basel}, issn = {2079-4991}, doi = {10.3390/nano10122521}, pages = {11}, year = {2020}, abstract = {The paper describes a new kind of ionogel with both good mechanical strength and high conductivity synthesized by confining the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Bmim][NTf₂]) within an organic-inorganic hybrid host. The organic-inorganic host network was synthesized by the reaction of methyltrimethoxysilane (MTMS), tetraethoxysilane (TEOS), and methyl methacrylate (MMA) in the presence of a coupling agent, offering the good mechanical strength and rapid shape recovery of the final products. The silane coupling agent 3-methacryloxypropyltrimethoxysilane (KH-570) plays an important role in improving the mechanical strength of the inorganic-organic hybrid, because it covalently connected the organic component MMA and the inorganic component SiO₂. Both the thermal stability and mechanical strength of the ionogel significantly increased by the addition of IL. The immobilization of [Bmim][NTf₂] within the ionogel provided the final ionogel with an ionic conductivity as high as ca. 0.04 S cm⁻¹ at 50 °C. Moreover, the hybrid ionogel can be modified with organosilica-modified carbon dots within the network to yield a transparent and flexible ionogel with strong excitation-dependent emission between 400 and 800 nm. The approach is, therefore, a blueprint for the construction of next-generation multifunctional ionogels.}, language = {en} } @article{KimKimParketal.2022, author = {Kim, Jiyong and Kim, Yohan and Park, Kyoungwon and Boeffel, Christine and Choi, Hyung-Seok and Taubert, Andreas and Wedel, Armin}, title = {Ligand Effect in 1-Octanethiol Passivation of InP/ZnSe/ZnS Quantum Dots-Evidence of Incomplete Surface Passivation during Synthesis}, series = {Small : nano micro}, journal = {Small : nano micro}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1613-6810}, doi = {10.1002/smll.202203093}, pages = {11}, year = {2022}, abstract = {The lack of anionic carboxylate ligands on the surface of InP/ZnSe/ZnS quantum dots (QDs), where zinc carboxylate ligands can be converted to carboxylic acid or carboxylate ligands via proton transfer by 1-octanethiol, is demonstrated. The as-synthesized QDs initially have an under-coordinated vacancy surface, which is passivated by solvent ligands such as ethanol and acetone. Upon exposure of 1-octanethiol to the QD surface, 1-octanethiol effectively induces the surface binding of anionic carboxylate ligands (derived from zinc carboxylate ligands) by proton transfer, which consequently exchanges ethanol and acetone ligands that bind on the incomplete QD surface. These systematic chemical analyses, such as thermogravimetric analysis-mass spectrometry and proton nuclear magnetic resonance spectroscopy, directly show the interplay of surface ligands, and it associates with QD light-emitting diodes (QD-LEDs). It is believed that this better understanding can lead to industrially feasible QD-LEDs.}, language = {en} } @article{BagdahnTaubert2013, author = {Bagdahn, Christian and Taubert, Andreas}, title = {Ionogel fiber mats - functional materials via electrospinning of PMMA and the ionic liquid bis(1-butyl-3-methyl-imidazolium) Tetrachloridocuprate(II), [Bmim](2)[CuCl4]}, series = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences}, volume = {68}, journal = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences}, number = {10}, publisher = {De Gruyter}, address = {T{\"u}bingen}, issn = {0932-0776}, doi = {10.5560/ZNB.2013-3195}, pages = {1163 -- 1171}, year = {2013}, abstract = {Ionogel fiber mats were made by electrospinning poly(methylmethacrylate) (PMMA) and the ionic liquid (IL) bis(1-butyl-3-methyl-imidazolium) tetrachloridocupraten, [Bmim](2)[CuCl4], from acetone. The morphology of the electrospun ionogels strongly depends on the spinning parameters. Dense and uniform fiber mats were only obtained at concentrations of 60 to 70 g of polymer and IL mass combined. Lower concentrations led to a low number of poorly defined fibers. High voltages of 20 to 25 kV led to well-defined and uniform fibers; voltages between 15 and 20 kV again led to less uniform and less dense fibers. At 10 kV and lower, no spinning could be induced. Finally, PMMA fibers electrospun without IL show a less well-defined morphology combining fibers and oblong droplets indicating that the IL has a beneficial effect on the electrospinning process. The resulting materials are prototypes for new functional materials, for example in sterile filtration.}, language = {en} } @article{BalischewskiBehrensZehbeetal.2020, author = {Balischewski, Christian and Behrens, Karsten and Zehbe, Kerstin and G{\"u}nter, Christina and Mies, Stefan and Sperlich, Eric and Kelling, Alexandra and Taubert, Andreas}, title = {Ionic liquids with more than one metal}, series = {Chemistry - a European journal}, volume = {26}, journal = {Chemistry - a European journal}, number = {72}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.202003097}, pages = {17504 -- 17513}, year = {2020}, abstract = {Thirteen N-butylpyridinium salts, including three monometallic [C4Py](2)[MCl4], nine bimetallic [C4Py](2)[(M1-xMxCl4)-M-a-Cl-b] and one trimetallic compound [C4Py](2)[(M1-y-zMyMz (c) Cl4)-M-a-M-b] (M=Co, Cu, Mn; x=0.25, 0.50 or 0.75 and y=z=0.33), were synthesized and their structure and thermal and electrochemical properties were studied. All compounds are ionic liquids (ILs) with melting points between 69 and 93 degrees C. X-ray diffraction proves that all ILs are isostructural. The conductivity at room temperature is between 10(-4) and 10(-8) S cm(-1). Some Cu-based ILs reach conductivities of 10(-2) S cm(-1), which is, however, probably due to IL dec. This correlates with the optical bandgap measurements indicating the formation of large bandgap semiconductors. At elevated temperatures approaching the melting points, the conductivities reach up to 1.47x10(-1) S cm(-1) at 70 degrees C. The electrochemical stability windows of the ILs are between 2.5 and 3.0 V.}, language = {en} } @article{PereiraZehbeGuenteretal.2018, author = {Pereira, Rui F. P. and Zehbe, Kerstin and G{\"u}nter, Christina and dos Santos, Tiago and Nunes, Silvia C. and Almeida Paz, Filipe A. and Silva, Maria M. and Granja, Pedro L. and Taubert, Andreas and de Zea Bermudez, Ver{\´o}nica}, title = {Ionic liquid-assisted synthesis of mesoporous silk fibroin/silica hybrids for biomedical applications}, series = {ACS Omega}, volume = {3}, journal = {ACS Omega}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {2470-1343}, doi = {10.1021/acsomega.8b02051}, pages = {10811 -- 10822}, year = {2018}, abstract = {New mesoporous silk fibroin (SF)/silica hybrids were processed via a one-pot soft and energy-efficient sol-gel chemistry and self-assembly from a silica precursor, an acidic or basic catalyst, and the ionic liquid 1-butyl-3-methylimidazolium chloride, acting as both solvent and mesoporosity-inducer. The as-prepared materials were obtained as slightly transparent-opaque, amorphous monoliths, easily transformed into powders, and stable up to ca. 300 degrees C. Structural data suggest the formation of a hexagonal mesostructure with low range order and apparent surface areas, pore volumes, and pore radii of 205-263 m(2) g(-1), 0.16-0.19 cm(3) g(-1), and 1.2-1.6 nm, respectively. In all samples, the dominating conformation of the SF chains is the beta-sheet. Cytotoxicity/bioactivity resazurin assays and fluorescence microscopy demonstrate the high viability of MC3T3 pre-osteoblasts to indirect (>= 99 +/- 9\%) and direct (78 +/- 2 to 99 +/- 13\%) contact with the SF/silica materials. Considering their properties and further improvements, these systems are promising candidates to be explored in bone tissue engineering. They also offer excellent prospects as electrolytes for solid-state electrochemical devices, in particular for fuel cells.}, language = {en} } @article{SalamaNeumannGuenteretal.2014, author = {Salama, Ahmed and Neumann, Mike and G{\"u}nter, Christina and Taubert, Andreas}, title = {Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials}, series = {Beilstein journal of nanotechnology}, volume = {5}, journal = {Beilstein journal of nanotechnology}, publisher = {Beilstein-Institut zur F{\"o}rderung der Chemischen Wissenschaften}, address = {Frankfurt, Main}, issn = {2190-4286}, doi = {10.3762/bjnano.5.167}, pages = {1553 -- 1568}, year = {2014}, abstract = {Cellulose/calcium phosphate hybrid materials were synthesized via an ionic liquid-assisted route. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis show that, depending on the reaction conditions, cellulose/hydroxyapatite, cellulose/ chlorapatite, or cellulose/monetite composites form. Preliminary studies with MC3T3-E1 pre-osteoblasts show that the cells proliferate on the hybrid materials suggesting that the ionic liquid-based process yields materials that are potentially useful as scaffolds for regenerative therapies.}, language = {en} } @article{AbdouAlonsoBrunetal.2022, author = {Abdou, Nicole and Alonso, Bruno and Brun, Nicolas and Landois, Perine and Taubert, Andreas and Hesemann, Peter and Mehdi, Ahmad}, title = {Ionic guest in ionic host}, series = {Materials chemistry frontiers}, volume = {6}, journal = {Materials chemistry frontiers}, number = {7}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2052-1537}, doi = {10.1039/d2qm00021k}, pages = {939 -- 947}, year = {2022}, abstract = {Ionosilica ionogels, i.e. composites consisting of an ionic liquid (IL) guest confined in an ionosilica host matrix, were synthesized via a non-hydrolytic sol-gel procedure from a tris-trialcoxysilylated amine precursor using the IL [BMIM]NTf2 as solvent. Various ionosilica ionogels were prepared starting from variable volumes of IL in the presence of formic acid. The resulting brittle and nearly colourless monoliths are composed of different amounts of IL guests confined in an ionosilica host as evidenced via thermogravimetric analysis, FT-IR, and C-13 CP-MAS solid-state NMR spectroscopy. In the following, we focused on confinement effects between the ionic host and guest. Special host-guest interactions between the IL guest and the ionosilica host were evidenced by H-1 solid-state NMR, Raman spectroscopy, and broadband dielectric spectroscopy (BDS) measurements. The three techniques indicate a strongly reduced ion mobility in the ionosilica ionogel composites containing small volume fractions of confined IL, compared to conventional silica-based ionogels. We conclude that the ionic ionosilica host stabilizes an IL layer on the host surface; this then results in a strongly reduced ion mobility compared to conventional silica hosts. The ion mobility progressively increases for systems containing higher volume fractions of IL and finally reaches the values observed in conventional silica based ionogels. These results therefore point towards strong interactions and confinement effects between the ionic host and the ionic guest on the ionosilica surface. Furthermore, this approach allows confining high volume fractions of IL into self-standing monoliths while preserving high ionic conductivity. These effects may be of interest in domains where IL phases must be anchored on solid supports to avoid leaching or IL spilling, e.g., in catalysis, in gas separation/sequestration devices or for the elaboration of solid electrolytes for (lithium-ion) batteries and supercapacitors.}, language = {en} } @article{WojnarowskaLangeTaubertetal.2021, author = {Wojnarowska, Zaneta and Lange, Alyna and Taubert, Andreas and Paluch, Marian}, title = {Ion and proton transport in aqueous/nonaqueous acidic tonic liquids for fuel-cell applications-insight from high-pressure dielectric studies}, series = {ACS applied materials \& interfaces / American Chemical Society}, volume = {13}, journal = {ACS applied materials \& interfaces / American Chemical Society}, number = {26}, publisher = {American Chemical Society}, address = {Washington}, issn = {1944-8244}, doi = {10.1021/acsami.1c06260}, pages = {30614 -- 30624}, year = {2021}, abstract = {The use of acidic ionic liquids and solids as electrolytes in fuel cells is an emerging field due to their efficient proton conductivity and good thermal stability. Despite multiple reports describing conducting properties of acidic ILs, little is known on the charge-transport mechanism in the vicinity of liquid-glass transition and the structural factors governing the proton hopping. To address these issues, we studied two acidic imidazolium-based ILs with the same cation, however, different anions-bulk tosylate vs small methanesulfonate. High-pressure dielectric studies of anhydrous and water-saturated materials performed in the close vicinity of T-g have revealed significant differences in the charge-transport mechanism in these two systems being undetectable at ambient conditions. Thereby, we demonstrated the effect of molecular architecture on proton hopping, being crucial in the potential electrochemical applications of acidic ILs.}, language = {en} } @article{HentrichJungingerBrunsetal.2015, author = {Hentrich, Doreen and Junginger, Mathias and Bruns, Michael and Boerner, Hans G. and Brandt, Jessica and Brezesinski, Gerald and Taubert, Andreas}, title = {Interface-controlled calcium phosphate mineralization: effect of oligo(aspartic acid)-rich interfaces}, series = {CrystEngComm}, volume = {17}, journal = {CrystEngComm}, number = {36}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1466-8033}, doi = {10.1039/c4ce02274b}, pages = {6901 -- 6913}, year = {2015}, abstract = {The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air-water and air-buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression-expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH.}, language = {en} } @article{HentrichJungingerBrunsetal.2015, author = {Hentrich, Doreen and Junginger, Mathias and Bruns, Michael and B{\"o}rner, Hans Gerhard and Brandt, Jessica and Brezesinski, Gerald and Taubert, Andreas}, title = {Interface-controlled calcium phosphate mineralization}, series = {CrystEngComm}, journal = {CrystEngComm}, number = {17}, publisher = {Royal Society of Chemistry}, address = {London}, issn = {1466-8033}, doi = {10.1039/C4CE02274B}, pages = {6901 -- 6913}, year = {2015}, abstract = {The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air-water and air-buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression-expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH.}, language = {en} } @article{DelahayeXieSchaeferetal.2011, author = {Delahaye, Emilie and Xie, Zailai and Sch{\"a}fer, Andreas and Douce, Laurent and Rogez, Guillaume and Rabu, Pierre and G{\"u}nter, Christina and Gutmann, Jochen S. and Taubert, Andreas}, title = {Intercalation synthesis of functional hybrid materials based on layered simple hydroxide hosts and ionic liquid guests - a pathway towards multifunctional ionogels without a silica matrix?}, series = {Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry}, volume = {40}, journal = {Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry}, number = {39}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1477-9226}, doi = {10.1039/c1dt10841g}, pages = {9977 -- 9988}, year = {2011}, abstract = {Functional hybrid materials on the basis of inorganic hosts and ionic liquids (ILs) as guests hold promise for a virtually unlimited number of applications. In particular, the interaction and the combination of properties of a defined inorganic matrix and a specific IL could lead to synergistic effects in property selection and tuning. Such hybrid materials, generally termed ionogels, are thus an emerging topic in hybrid materials research. The current article addresses some of the recent developments and focuses on the question why silica is currently the dominating matrix used for (inorganic) ionogel fabrication. In comparison to silica, matrix materials such as layered simple hydroxides, layered double hydroxides, clay-type substances, magnetic or catalytically active solids, and many other compounds could be much more interesting because they themselves may carry useful functionalities, which could also be exploited for multifunctional hybrid materials synthesis. The current article combines experimental results with some arguments as to how new, advanced functional hybrid materials can be generated and which obstacles will need to be overcome to successfully achieve the synthesis of a desired target material.}, language = {en} } @article{UchidaBinetAroraetal.2018, author = {Uchida, Ryusuke and Binet, Silvia and Arora, Neha and Jacopin, Gwenole and Alotaibi, Mohammad Hayal and Taubert, Andreas and Zakeeruddin, Shaik Mohammed and Dar, M. Ibrahim and Graetzel, Michael}, title = {Insights about the Absence of Rb Cation from the 3D Perovskite Lattice}, series = {Small}, volume = {14}, journal = {Small}, number = {36}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1613-6810}, doi = {10.1002/smll.201802033}, pages = {7}, year = {2018}, abstract = {Efficiencies >20\% are obtained from the perovskite solar cells (PSCs) employing Cs+ and Rb+ based perovskite compositions; therefore, it is important to understand the effect of these inorganic cations specifically Rb+ on the properties of perovskite structures. Here the influence of Cs+ and Rb+ is elucidated on the structural, morphological, and photophysical properties of perovskite structures and the photovoltaic performances of resulting PSCs. Structural, photoluminescence (PL), and external quantum efficiency studies establish the incorporation of Cs+ (x < 10\%) but amply rule out the possibility of Rb-incorporation into the MAPbI(3) (MA = CH3NH3+) lattice. Moreover, morphological studies and time-resolved PL show that both Cs+ and Rb+ detrimentally affect the surface coverage of MAPbI(3) layers and charge-carrier dynamics, respectively, by influencing nucleation density and by inducing nonradiative recombination. In addition, differential scanning calorimetry shows that the transition from orthorhombic to tetragonal phase occurring around 160 K requires more thermal energy for the Cs-containing MAPbI(3) systems compared to the pristine MAPbI(3). Investigation including mixed halide (I/Br) and mixed cation A-cation based compositions further confirms the absence of Rb+ from the 3D-perovskite lattice. The fundamental insights gained through this work will be of great significance to further understand highly promising perovskite compositions.}, language = {en} }