TY - GEN A1 - Hentrich, Doreen A1 - Junginger, Mathias A1 - Bruns, Michael A1 - Börner, Hans Gerhard A1 - Brandt, Jessica A1 - Brezesinski, Gerald A1 - Taubert, Andreas T1 - Interface-controlled calcium phosphate mineralization BT - effect of oligo(aspartic acid)-rich interfaces N2 - The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air–water and air–buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression–expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 213 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-89540 SP - 6901 EP - 6913 ER - TY - GEN A1 - Xie, Zai-Lai A1 - Huang, Xing A1 - Titirici, Maria-Magdalena A1 - Taubert, Andreas T1 - Mesoporous graphite nanoflakes via ionothermal carbonization of fructose and their use in dye removal N2 - The large-scale green synthesis of graphene-type two-dimensional materials is still challenging. Herein, we describe the ionothermal synthesis of carbon-based composites from fructose in the iron-containing ionic liquid 1-butyl-3-methylimidazolium tetrachloridoferrate(III), [Bmim][FeCl4] serving as solvent, catalyst, and template for product formation. The resulting composites consist of oligo-layer graphite nanoflakes and iron carbide particles. The mesoporosity, strong magnetic moment, and high specific surface area of the composites make them attractive for water purification with facile magnetic separation. Moreover, Fe3Cfree graphite can be obtained via acid etching, providing access to fairly large amounts of graphite material. The current approach is versatile and scalable, and thus opens the door to ionothermal synthesis towards the larger-scale synthesis of materials that are, although not made via a sustainable process, useful for water treatment such as the removal of organic molecules. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 283 Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-99427 ER - TY - GEN A1 - Junginger, Mathias A1 - Kübel, Christian A1 - Schacher, Felix H. A1 - Müller, Axel H. E. A1 - Taubert, Andreas T1 - Crystal structure and chemical composition of biomimetic calcium phosphate nanofibers N2 - Calcium phosphate nanofibers with a diameter of only a few nanometers and a cotton-ball-like aggregate morphology have been reported several times in the literature. Although fiber formation seems reproducible in a variety of conditions, the crystal structure and chemical composition of the fibers have been elusive. Using scanning transmission electron microscopy, low dose electron (nano)diffraction, energy-dispersive X-ray spectroscopy, and energy-filtered transmission electron microscopy, we have assigned crystal structures and chemical compositions to the fibers. Moreover, we demonstrate that the mineralization process yields true polymer/calcium phosphate hybrid materials where the block copolymer template is closely associated with the calcium phosphate. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 244 KW - air-water-interface KW - polycationic monolayer KW - mineralization beneath KW - block-copolymers KW - aqueous-solution KW - morphology KW - orthophosphates KW - biomaterials KW - nucleation KW - clusters Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95176 SP - 11301 EP - 11308 ER - TY - GEN A1 - Kirchhecker, Sarah A1 - Tröger-Müller, Steffen A1 - Bake, Sebastian A1 - Antonietti, Markus A1 - Taubert, Andreas A1 - Esposito, Davido T1 - Renewable pyridinium ionic liquids from the continuous hydrothermal decarboxylation of furfural-amino acid derived pyridinium zwitterions N2 - Fully renewable pyridinium ionic liquids were synthesised via the hydrothermal decarboxylation of pyridinium zwitterions derived from furfural and amino acids in flow. The functionality of the resulting ionic liquid (IL) can be tuned by choice of different amino acids as well as different natural carboxylic acids as the counterions. A representative member of this new class of ionic liquids was successfully used for the synthesis of ionogels and as a solvent for the Heck coupling. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 198 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-81390 ER - TY - JOUR A1 - Pan, Xuefeng A1 - Sarhan, Radwan Mohamed A1 - Kochovski, Zdravko A1 - Chen, Guosong A1 - Taubert, Andreas A1 - Mei, Shilin A1 - Lu, Yan T1 - Template synthesis of dual-functional porous MoS2 nanoparticles with photothermal conversion and catalytic properties JF - Nanoscale N2 - Advanced catalysis triggered by photothermal conversion effects has aroused increasing interest due to its huge potential in environmental purification. In this work, we developed a novel approach to the fast degradation of 4-nitrophenol (4-Nip) using porous MoS2 nanoparticles as catalysts, which integrate the intrinsic catalytic property of MoS2 with its photothermal conversion capability. Using assembled polystyrene-b-poly(2-vinylpyridine) block copolymers as soft templates, various MoS 2 particles were prepared, which exhibited tailored morphologies (e.g., pomegranate-like, hollow, and open porous structures). The photothermal conversion performance of these featured particles was compared under near-infrared (NIR) light irradiation. Intriguingly, when these porous MoS2 particles were further employed as catalysts for the reduction of 4-Nip, the reaction rate constant was increased by a factor of 1.5 under NIR illumination. We attribute this catalytic enhancement to the open porous architecture and light-to-heat conversion performance of the MoS2 particles. This contribution offers new opportunities for efficient photothermal-assisted catalysis. Y1 - 2022 U6 - https://doi.org/10.1039/d2nr01040b SN - 2040-3372 VL - 14 IS - 18 SP - 6888 EP - 6901 PB - RSC Publ. (Royal Society of Chemistry) CY - Cambridge ER - TY - GEN A1 - Figueroa Campos, Gustavo A. A1 - G. K. T. Kruizenga, Johannes A1 - Sagu Tchewonpi, Sorel A1 - Schwarz, Steffen A1 - Homann, Thomas A1 - Taubert, Andreas A1 - Rawel, Harshadrai T1 - Effect of the Post-Harvest Processing on Protein Modification in Green Coffee Beans by Phenolic Compounds T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The protein fraction, important for coffee cup quality, is modified during post-harvest treatment prior to roasting. Proteins may interact with phenolic compounds, which constitute the major metabolites of coffee, where the processing affects these interactions. This allows the hypothesis that the proteins are denatured and modified via enzymatic and/or redox activation steps. The present study was initiated to encompass changes in the protein fraction. The investigations were limited to major storage protein of green coffee beans. Fourteen Coffea arabica samples from various processing methods and countries were used. Different extraction protocols were compared to maintain the status quo of the protein modification. The extracts contained about 4–8 µg of chlorogenic acid derivatives per mg of extracted protein. High-resolution chromatography with multiple reaction monitoring was used to detect lysine modifications in the coffee protein. Marker peptides were allocated for the storage protein of the coffee beans. Among these, the modified peptides K.FFLANGPQQGGK.E and R.LGGK.T of the α-chain and R.ITTVNSQK.I and K.VFDDEVK.Q of β-chain were detected. Results showed a significant increase (p < 0.05) of modified peptides from wet processed green beans as compared to the dry ones. The present study contributes to a better understanding of the influence of the different processing methods on protein quality and its role in the scope of coffee cup quality and aroma. View Full-Text T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1256 KW - Arabica coffee KW - coffee processing KW - protein modification KW - bound phenolic compounds KW - peptide biomarkers KW - LC-MS/MS Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-557643 SN - 1866-8372 VL - 11 SP - 1 EP - 19 PB - Universitätsverlag Potsdam CY - Potsdam ET - 2 ER - TY - GEN A1 - Krüger, Stefanie A1 - Schwarze, Michael A1 - Baumann, Otto A1 - Günter, Christina A1 - Bruns, Michael A1 - Kübel, Christian A1 - Szabó, Dorothée Vinga A1 - Meinusch, Rafael A1 - de Zea Bermudez, Verónica A1 - Taubert, Andreas T1 - Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting BT - combining renewable raw materials with clean fuels T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - The synthesis, structure, and photocatalytic water splitting performance of two new titania (TiO 2 )/gold(Au)/Bombyx mori silk hybrid materials are reported. All materials are monoliths with diameters of up to ca. 4.5 cm. The materials are macroscopically homogeneous and porous with surface areas between 170 and 210 m 2/g. The diameter of the TiO 2 nanoparticles (NPs) – mainly anatase with a minor fraction of brookite – and the Au NPs are on the order of 5 and 7–18 nm, respectively. Addition of poly(ethylene oxide) to the reaction mixture enables pore size tuning, thus providing access to different materials with different photocatalytic activities. Water splitting experiments using a sunlight simulator and a Xe lamp show that the new hybrid materials are effective water splitting catalysts and produce up to 30 mmol of hydrogen per 24 h. Overall the article demonstrates that the combination of a renewable and robust scaffold such as B. mori silk with a photoactive material provides a promising approach to new monolithic photocatalysts that can easily be recycled and show great potential for application in lightweight devices for green fuel production. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 581 KW - Bombyx mori silk KW - gold KW - photocatalytic water splitting KW - titania Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423499 SN - 1866-8372 IS - 581 ER - TY - GEN A1 - Mai, Tobias A1 - Boye, Susanne A1 - Yuan, Jiayin A1 - Völkel, Antje A1 - Gräwert, Marlies A1 - Günter, Christina A1 - Lederer, Albena A1 - Taubert, Andreas T1 - Poly(ethylene oxide)-based block copolymers with very high molecular weights for biomimetic calcium phosphate mineralization N2 - The present article is among the first reports on the effects of poly(ampholyte)s and poly(betaine)s on the biomimetic formation of calcium phosphate. We have synthesized a series of di- and triblock copolymers based on a non-ionic poly(ethylene oxide) block and several charged methacrylate monomers, 2-(trimethylammonium)ethyl methacrylate chloride, 2-((3-cyanopropyl)-dimethylammonium)ethyl methacrylate chloride, 3-sulfopropyl methacrylate potassium salt, and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide. The resulting copolymers are either positively charged, ampholytic, or betaine block copolymers. All the polymers have very high molecular weights of over 106 g mol−1. All polymers are water-soluble and show a strong effect on the precipitation and dissolution of calcium phosphate. The strongest effects are observed with triblock copolymers based on a large poly(ethylene oxide) middle block (nominal Mn = 100 000 g mol−1). Surprisingly, the data show that there is a need for positive charges in the polymers to exert tight control over mineralization and dissolution, but that the exact position of the charge in the polymer is of minor importance for both calcium phosphate precipitation and dissolution. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 208 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-85299 ER - TY - JOUR A1 - Hamed Misbah, Mohamed A1 - Santos, Mercedes A1 - Quintanilla, Luis A1 - Günter, Christina A1 - Alonso, Matilde A1 - Taubert, Andreas A1 - Carlos Rodriguez-Cabello, Jose T1 - Recombinant DNA technology and click chemistry: a powerful combination for generating a hybrid elastin-like-statherin hydrogel to control calcium phosphate mineralization JF - Beilstein journal of nanotechnology N2 - Understanding the mechanisms responsible for generating different phases and morphologies of calcium phosphate by elastin-like recombinamers is supreme for bioengineering of advanced multifunctional materials. The generation of such multifunctional hybrid materials depends on the properties of their counterparts and the way in which they are assembled. The success of this assembly depends on the different approaches used, such as recombinant DNA technology and click chemistry. In the present work, an elastin-like recombinamer bearing lysine amino acids distributed along the recombinamer chain has been cross-linked via Huisgen [2 + 3] cycloaddition. The recombinamer contains the SN(A)15 peptide domains inspired by salivary statherin, a peptide epitope known to specifically bind to and nucleate calcium phosphate. The benefit of using click chemistry is that the hybrid elastin-like-statherin recombinamers cross-link without losing their fibrillar structure. Mineralization of the resulting hybrid elastin-like-statherin recombinamer hydrogels with calcium phosphate is described. Thus, two different hydroxyapatite morphologies (cauliflower- and plate-like) have been formed. Overall, this study shows that crosslinking elastin-like recombinamers leads to interesting matrix materials for the generation of calcium phosphate composites with potential applications as biomaterials. KW - calcium phosphate KW - elastin-like recombinamers KW - hydroxyapatite KW - mineralization KW - SN(A)15 Y1 - 2017 U6 - https://doi.org/10.3762/bjnano.8.80 SN - 2190-4286 VL - 8 SP - 772 EP - 783 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - JOUR A1 - Delahaye, Emilie A1 - Xie, Zailai A1 - Schäfer, Andreas A1 - Douce, Laurent A1 - Rogez, Guillaume A1 - Rabu, Pierre A1 - Günter, Christina A1 - Gutmann, Jochen S. A1 - Taubert, Andreas T1 - Intercalation synthesis of functional hybrid materials based on layered simple hydroxide hosts and ionic liquid guests - a pathway towards multifunctional ionogels without a silica matrix? JF - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry N2 - Functional hybrid materials on the basis of inorganic hosts and ionic liquids (ILs) as guests hold promise for a virtually unlimited number of applications. In particular, the interaction and the combination of properties of a defined inorganic matrix and a specific IL could lead to synergistic effects in property selection and tuning. Such hybrid materials, generally termed ionogels, are thus an emerging topic in hybrid materials research. The current article addresses some of the recent developments and focuses on the question why silica is currently the dominating matrix used for (inorganic) ionogel fabrication. In comparison to silica, matrix materials such as layered simple hydroxides, layered double hydroxides, clay-type substances, magnetic or catalytically active solids, and many other compounds could be much more interesting because they themselves may carry useful functionalities, which could also be exploited for multifunctional hybrid materials synthesis. The current article combines experimental results with some arguments as to how new, advanced functional hybrid materials can be generated and which obstacles will need to be overcome to successfully achieve the synthesis of a desired target material. Y1 - 2011 U6 - https://doi.org/10.1039/c1dt10841g SN - 1477-9226 VL - 40 IS - 39 SP - 9977 EP - 9988 PB - Royal Society of Chemistry CY - Cambridge ER -