@misc{AbouserieSchildeTaubert2018, author = {Abouserie, Ahed and Schilde, Uwe and Taubert, Andreas}, title = {The crystal structure of N-butylpyridinium bis(μ2-dichlorido)-tetrachloridodicopper(II), C₁₈H₂₈N₂Cu₂Cl₆}, series = {Zeitschrift f{\"u}r Kristallographie - New Crystal Structures}, journal = {Zeitschrift f{\"u}r Kristallographie - New Crystal Structures}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417310}, pages = {4}, year = {2018}, abstract = {C₉H₁₄Cl₃CuN, monoclinic, P2₁/n (no. 14), a = 9.6625(6) {\AA}, b = 9.3486(3) {\AA}, c = 14.1168(8) {\AA}, β = 102.288(5)°, V = 1245.97(11) {\AA}³, Z = 4, Rgₜ(F) = 0.0182, wRᵣₑf(F²) = 0.0499, T = 210(2) K.}, language = {en} } @misc{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 = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1316}, issn = {1866-8372}, doi = {10.25932/publishup-58751}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-587512}, 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} } @misc{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 = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1341}, issn = {1866-8372}, doi = {10.25932/publishup-60487}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-604874}, 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} } @misc{BlockGuenterRodriguesetal.2021, author = {Block, Inga and G{\"u}nter, Christina and Rodrigues, Alysson Duarte and Paasch, Silvia and Hesemann, Peter and Taubert, Andreas}, title = {Carbon Adsorbents from Spent Coffee for Removal of Methylene Blue and Methyl Orange from Water}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {14}, issn = {1866-8372}, doi = {10.25932/publishup-52165}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-521653}, pages = {20}, year = {2021}, abstract = {Activated carbons (ACs) were prepared from dried spent coffee (SCD), a biological waste product, to produce adsorbents for methylene blue (MB) and methyl orange (MO) from aqueous solution. Pre-pyrolysis activation of SCD was achieved via treatment of the SCD with aqueous sodium hydroxide solutions at 90 °C. Pyrolysis of the pretreated SCD at 500 °C for 1 h produced powders with typical characteristics of AC suitable and effective for dye adsorption. As an alternative to the rather harsh base treatment, calcium carbonate powder, a very common and abundant resource, was also studied as an activator. Mixtures of SCD and CaCO3 (1:1 w/w) yielded effective ACs for MO and MB removal upon pyrolysis needing only small amounts of AC to clear the solutions. A selectivity of the adsorption process toward anionic (MO) or cationic (MB) dyes was not observed.}, language = {en} } @misc{FigueroaCamposGKTKruizengaSaguTchewonpietal.2022, author = {Figueroa Campos, Gustavo A. and G. K. T. Kruizenga, Johannes and Sagu Tchewonpi, Sorel and Schwarz, Steffen and Homann, Thomas and Taubert, Andreas and Rawel, Harshadrai}, title = {Effect of the Post-Harvest Processing on Protein Modification in Green Coffee Beans by Phenolic Compounds}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, volume = {11}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, edition = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8372}, doi = {10.25932/publishup-55764}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-557643}, pages = {1 -- 19}, year = {2022}, abstract = {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}, language = {en} } @misc{FigueroaCamposPerezBlocketal.2021, author = {Figueroa Campos, Gustavo A. and Perez, Jeffrey Paulo H. and Block, Inga and Tchewonpi Sagu, 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 = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {8}, issn = {1866-8372}, doi = {10.25932/publishup-52191}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-521914}, pages = {20}, 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} } @misc{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}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89540}, 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} } @misc{HentrichTauerEspanoletal.2017, author = {Hentrich, Doreen and Tauer, Klaus and Espanol, Montserrat and Ginebra, Maria-Pau and Taubert, Andreas}, title = {EDTA and NTA effectively tune the mineralization of calcium phosphate from bulk aqueous solution}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1095}, issn = {1866-8372}, doi = {10.25932/publishup-46918}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-469186}, pages = {23}, year = {2017}, abstract = {This study describes the effects of nitrilotriacetic acid (NTA) and ethylenediaminotetraacetic acid (EDTA) on themineralization of calciumphosphate from bulk aqueous solution. Mineralization was performed between pH 6 and 9 and with NTA or EDTA concentrations of 0, 5, 10, and 15 mM. X-ray diffraction and infrared spectroscopy show that at low pH, mainly brushite precipitates and at higher pH, mostly hydroxyapatite forms. Both additives alter the morphology of the precipitates. Without additive, brushite precipitates as large plates. With NTA, the morphology changes to an unusual rod-like shape. With EDTA, the edges of the particles are rounded and disk-like particles form. Conductivity and pH measurements suggest that the final products form through several intermediate steps.}, language = {en} } @misc{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 = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1026}, issn = {1866-8372}, doi = {10.25932/publishup-48603}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-486032}, pages = {26}, 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} } @misc{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 = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1093}, issn = {1866-8372}, doi = {10.25932/publishup-48898}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-488987}, pages = {13}, 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} } @misc{JeličićFriedrichJeremićetal.2009, author = {Jeličić, Aleksandra and Friedrich, Alwin and Jeremić, Katarina and Siekmeyer, Gerd and Taubert, Andreas}, title = {Polymer hydrogel/polybutadiene/iron oxide nanoparticle hybrid actuators for the characterization of NiTi implants}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-48589}, year = {2009}, abstract = {One of the main issues with the use of nickel titanium alloy (NiTi) implants in cardiovascular implants (stents) is that these devices must be of very high quality in order to avoid subsequent operations due to failing stents. For small stents with diameters below ca. 2 mm, however, stent characterization is not straightforward. One of the main problems is that there are virtually no methods to characterize the interior of the NiTi tubes used for fabrication of these tiny stents. The current paper reports on a robust hybrid actuator for the characterization of NiTi tubes prior to stent fabrication. The method is based on a polymer/hydrogel/magnetic nanoparticle hybrid material and allows for the determination of the inner diameter at virtually all places in the raw NiTi tubes. Knowledge of the inner structure of the raw NiTi tubes is crucial to avoid regions that are not hollow or regions that are likely to fail due to defects inside the raw tube. The actuator enables close contact of a magnetic polymer film with the inner NiTi tube surface. The magnetic signal can be detected from outside and be used for a direct mapping of the tube interior. As a result, it is possible to detect critical regions prior to expensive and slow stent fabrication processes.}, language = {en} } @misc{JungingerKuebelSchacheretal.2013, author = {Junginger, Mathias and K{\"u}bel, Christian and Schacher, Felix H. and M{\"u}ller, Axel H. E. and Taubert, Andreas}, title = {Crystal structure and chemical composition of biomimetic calcium phosphate nanofibers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-95176}, pages = {11301 -- 11308}, year = {2013}, abstract = {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.}, language = {en} } @misc{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}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81390}, 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} } @misc{KruegerSchwarzeBaumannetal.2018, author = {Kr{\"u}ger, Stefanie and Schwarze, Michael and Baumann, Otto and G{\"u}nter, Christina and Bruns, Michael and K{\"u}bel, Christian and Szab{\´o}, Doroth{\´e}e Vinga and Meinusch, Rafael and de Zea Bermudez, Ver{\´o}nica and Taubert, Andreas}, title = {Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {581}, issn = {1866-8372}, doi = {10.25932/publishup-42349}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423499}, pages = {18}, year = {2018}, abstract = {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.}, language = {en} } @misc{LiTaubert2009, author = {Li, Zhonghao and Taubert, Andreas}, title = {Cellulose/gold nanocrystal hybrids via an ionic liquid/aqueous precipitation route}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45046}, year = {2009}, abstract = {Injection of a mixture of HAuCl4 and cellulose dissolved in the ionic liquid (IL) 1-butyl-3-methylimidazolium chloride [Bmim]Cl into aqueous NaBH4 leads to colloidal gold nanoparticle/cellulose hybrid precipitates. This process is a model example for a very simple and generic approach towards (noble) metal/cellulose hybrids, which could find applications in sensing, sterile filtration, or as biomaterials.}, language = {en} } @misc{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}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85299}, 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} } @misc{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 = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {8}, issn = {1866-8372}, doi = {10.25932/publishup-52508}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-525088}, pages = {18}, 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} } @misc{SchneiderGuenterTaubert2018, author = {Schneider, Matthias and G{\"u}nter, Christina and Taubert, Andreas}, title = {Co-deposition of a hydrogel/calcium phosphate hybrid layer on 3D printed poly(lactic acid) scaffolds via dip coating}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1057}, issn = {1866-8372}, doi = {10.25932/publishup-47442}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-474427}, pages = {21}, year = {2018}, abstract = {The article describes the surface modification of 3D printed poly(lactic acid) (PLA) scaffolds with calcium phosphate (CP)/gelatin and CP/chitosan hybrid coating layers. The presence of gelatin or chitosan significantly enhances CP co-deposition and adhesion of the mineral layer on the PLA scaffolds. The hydrogel/CP coating layers are fairly thick and the mineral is a mixture of brushite, octacalcium phosphate, and hydroxyapatite. Mineral formation is uniform throughout the printed architectures and all steps (printing, hydrogel deposition, and mineralization) are in principle amenable to automatization. Overall, the process reported here therefore has a high application potential for the controlled synthesis of biomimetic coatings on polymeric biomaterials.}, language = {en} } @misc{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 = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1058}, issn = {1866-8372}, doi = {10.25932/publishup-48733}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-487334}, pages = {13}, 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} } @misc{TaubertBalischewskiHentrichetal.2017, author = {Taubert, Andreas and Balischewski, Christian and Hentrich, Doreen and Elschner, Thomas and Eidner, Sascha and G{\"u}nter, Christina and Behrens, Karsten and Heinze, Thomas}, title = {Water-soluble cellulose derivatives are sustainable additives for biomimetic calcium phosphate mineralization}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-400453}, pages = {17}, year = {2017}, abstract = {The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer) contents reach 10\% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble) cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials.}, language = {en} }