TY  - JOUR
A1  - Zobir, Soraya Hadj
A1  - Altenberger, Uwe
A1  - Günter, Christina
T1  - Geochemistry and petrology of metamorphosed submarine basic ashes in the Edough Massif (Cap de Garde, Annaba, northeastern Algeria)
JF  - Comptes rendus geoscience
N2  - The study presents the first evidence of metamorphosed submarine ashes in the Edough Massif, in northeastern Algeria. It occurs below the greenschist-facies Tellian units that represent the thrusted Mesozoic to Eocene passive paleomargin of northern Africa deposited on thinned continental crust. The metamorphic complex consists of tectonically superposed units composed of gneisses (lower unit) and micaschists (upper unit). At the Cap de Garde, these units enclose an "intermediate unit" composed of micaschists and meter-thick layers of marbles, which are sometimes intercalated with amphibolites. The latter occur as discontinuous small lenses and layers. The amphibolites are parallel to the primary bedding of the marbles and the main foliation. Chemical markers and field observations indicate that they are metamorphic equivalents of basic igneous rocks. The lenticular character, low thickness and multiple intercalations with marine sediments and the unusual high lithium concentrations suggest subaqueous near-source basaltic ash-fall deposits in a marine environment. (C) 2014 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
KW  - Amphibolites
KW  - Submarine sediments
KW  - Basaltic ash-fall deposits
KW  - Edough
KW  - Algeria
Y1  - 2014
U6  - https://doi.org/10.1016/j.crte.2014.09.002
SN  - 1631-0713
SN  - 1778-7025
VL  - 346
IS  - 9-10
SP  - 244
EP  - 254
PB  - Elsevier
CY  - Paris
ER  - 
TY  - JOUR
A1  - Volante, Silvia
A1  - Pourteau, Amaury
A1  - Collins, William J.
A1  - Blereau, Eleanore
A1  - Li, Zheng-Xiang
A1  - Smit, Matthijs Arjen
A1  - Evans, Noreen
A1  - Nordsvan, Adam R.
A1  - Spencer, Chris J.
A1  - McDonald, Brad J.
A1  - Li, Jiangyu
A1  - Günter, Christina
T1  - Multiple P-T-d-t paths reveal the evolution of the final Nuna assembly in northeast Australia
JF  - Journal of metamorphic geology
N2  - The final assembly of the Mesoproterozoic supercontinent Nuna was marked by the collision of Laurentia and Australia at 1.60 Ga, which is recorded in the Georgetown Inlier of NE Australia. Here, we decipher the metamorphic evolution of this final Nuna collisional event using petrostructural analysis, major and trace element compositions of key minerals, thermodynamic modelling, and multi-method geochronology. The Georgetown Inlier is characterised by deformed and metamorphosed 1.70-1.62 Ga sedimentary and mafic rocks, which were intruded byc. 1.56 Ga old S-type granites. Garnet Lu-Hf and monazite U-Pb isotopic analyses distinguish two major metamorphic events (M1 atc. 1.60 Ga and M2 atc. 1.55 Ga), which allows at least two composite fabrics to be identified at the regional scale-c. 1.60 Ga S1 (consisting in fabrics S1a and S1b) andc. 1.55 Ga S2 (including fabrics S2a and S2b). Also, three tectono-metamorphic domains are distinguished: (a) the western domain, with S1 defined by low-P(LP) greenschist facies assemblages; (b) the central domain, where S1 fabric is preserved as medium-P(MP) amphibolite facies relicts, and locally as inclusion trails in garnet wrapped by the regionally dominant low-Pamphibolite facies S2 fabric; and (c) the eastern domain dominated by upper amphibolite to granulite facies S2 foliation. In the central domain, 1.60 GaMP-medium-T(MT) metamorphism (M1) developed within the staurolite-garnet stability field, with conditions ranging from 530-550 degrees C at 6-7 kbar (garnet cores) to 620-650 degrees C at 8-9 kbar (garnet rims), and it is associated with S1 fabric. The onset of 1.55 GaLP-high-T(HT) metamorphism (M2) is marked by replacement of staurolite by andalusite (M2a/D2a), which was subsequently pseudomorphed by sillimanite (M2b/D2b) where granite and migmatite are abundant.P-Tconditions ranged from 600 to 680 degrees C and 4-6 kbar for the M2b sillimanite stage. 1.60 Ga garnet relicts within the S2 foliation highlight the progressive obliteration of the S1 fabric by regional S2 in the central zone during peak M2 metamorphism. In the eastern migmatitic complex, partial melting of paragneiss and amphibolite occurred syn- to post-S2, at 730-770 degrees C and 6-8 kbar, and at 750-790 degrees C and 6 kbar, respectively. The pressure-temperature-deformation-time paths reconstructed for the Georgetown Inlier suggest ac. 1.60 Ga M1/D1 event recorded under greenschist facies conditions in the western domain and under medium-Pand medium-Tconditions in the central domain. This event was followed by the regional 1.56-1.54 Ga low-Pand high-Tphase (M2/D2), extensively recorded in the central and eastern domains. Decompression between these two metamorphic events is ascribed to an episode of exhumation. The two-stage evolution supports the previous hypothesis that the Georgetown Inlier preserves continental collisional and subsequent thermal perturbation associated with granite emplacement.
KW  - continental collision
KW  - Lu-Hf in garnet
KW  - petrostructural analysis
KW  - P-T-d-tpaths
KW  - supercontinent Nuna
Y1  - 2020
U6  - https://doi.org/10.1111/jmg.12532
SN  - 0263-4929
SN  - 1525-1314
VL  - 38
IS  - 6
SP  - 593
EP  - 627
PB  - Wiley-Blackwell
CY  - Oxford [u.a.]
ER  - 
TY  - JOUR
A1  - Unuabonah, Emmanuel
A1  - Nöske, Robert
A1  - Weber, Jens
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - New micro/mesoporous nanocomposite material from low-cost sources for the efficient removal of aromatic and pathogenic pollutants from water
JF  - Beilstein journal of nanotechnology
N2  - 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.
KW  - 4-nitrophenol
KW  - Carica papaya seeds
KW  - clay
KW  - E. coli
KW  - micro/mesoporous
KW  - nanocomposite
KW  - water remediation
Y1  - 2019
U6  - https://doi.org/10.3762/bjnano.10.11
SN  - 2190-4286
VL  - 10
SP  - 119
EP  - 131
PB  - Beilstein-Institut zur Förderung der Chemischen Wissenschaften
CY  - Frankfurt, Main
ER  - 
TY  - GEN
A1  - Unuabonah, Emmanuel I.
A1  - Nöske, Robert
A1  - Weber, Jens
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - New micro/mesoporous nanocomposite material from low-cost sources for the efficient removal of aromatic and pathogenic pollutants from water
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - 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 ≈150 and 300 m2/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 °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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 720 
KW  - 4-nitrophenol
KW  - Carica papaya seeds
KW  - clay
KW  - E. coli
KW  - micro/mesoporous
KW  - nanocomposite
KW  - water remediation
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426214
IS  - 720
SP  - 119
EP  - 131
ER  - 
TY  - JOUR
A1  - Unuabonah, Emmanuel I.
A1  - Kolawole, Matthew O.
A1  - Agunbiade, Foluso O.
A1  - Omorogie, Martins O.
A1  - Koko, Daniel T.
A1  - Ugwuja, Chidinma G.
A1  - Ugege, Leonard E.
A1  - Oyejide, Nicholas E.
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - Novel metal-doped bacteriostatic hybrid clay composites for point-of-use disinfection of water
JF  - Journal of Environmental Chemical Engineering
N2  - 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.
KW  - Kaolinite
KW  - Composites
KW  - Bacteria
KW  - Breakthrough time
KW  - Regeneration
Y1  - 2017
U6  - https://doi.org/10.1016/j.jece.2017.04.017
SN  - 2213-3437
VL  - 5
SP  - 2128
EP  - 2141
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Unuabonah, Emmanuel I.
A1  - Günter, Christina
A1  - Weber, Jens
A1  - Lubahn, Susanne
A1  - Taubert, Andreas
T1  - Hybrid Clay - a new highly efficient adsorbent for water treatment
JF  - ACS sustainable chemistry & engineering
N2  - New hybrid clay adsorbent based on kaolinite clay and Carica papaya seeds with improved cation exchange capacity (CEC), rate of heavy metal ion uptake, and adsorption capacity for heavy metal ions were prepared. The CEC of the new material is ca. 75 meq/100 g in spite of the unexpectedly low surface area (approximate to 19 m(2)/g). Accordingly, the average particle size of the hybrid clay adsorbent decreased from over 200 to 100 pm. The hybrid clay adsorbent is a highly efficient adsorbent for heavy metals. With an initial metal concentration of 1 mg/L, the hybrid clay adsorbent reduces the Cd2+, Ni2+, and Pb2+ concentration in aqueous solution to <= 4, <= 7 and <= 20 mu g/L, respectively, from the first minute to over 300 min using a fixed bed containing 2 g of adsorbent and a flow rate of approximate to 7 mL/min. These values are (with the exception of Pb2+) in line with the WHO permissible limits for heavy metal ions. In a cocktail solution of Cd2+, and Ni2+, the hybrid clay shows a reduced rate of uptake but an increased adsorption capacity. The CEC data suggest that the adsorption of Pb2+, Cd2+, and Ni2+ on the hybrid clay adsorbent is essentially due to ion exchange. This hybrid clay adsorbent is prepared from materials that are abundant and by a simple means that is sustainable, easily recovered from aqueous solution, nonbiodegradable (unlike numerous biosorbent), and easily regenerated and is a highly efficient alternative to activated carbon for water treatment.
KW  - Kaolinite
KW  - Hybrid clay
KW  - Water treatment
KW  - Cation exchange Capacity
KW  - Adsorbent
KW  - Kinetics
Y1  - 2013
U6  - https://doi.org/10.1021/sc400051y
SN  - 2168-0485
VL  - 1
IS  - 8
SP  - 966
EP  - 973
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Ugwuja, Chidinma G.
A1  - Adelowo, Olawale O.
A1  - Ogunlaja, Aemere
A1  - Omorogie, Martins O.
A1  - Olukanni, Olumide D.
A1  - Ikhimiukor, Odion O.
A1  - Iermak, Ievgeniia
A1  - Kolawole, Gabriel A.
A1  - Günter, Christina
A1  - Taubert, Andreas
A1  - Bodede, Olusola
A1  - Moodley, Roshila
A1  - Inada, Natalia M.
A1  - Camargo, Andrea S.S. de
A1  - Unuabonah, Emmanuel Iyayi
T1  - Visible-Light-Mediated Photodynamic Water Disinfection @ Bimetallic-Doped Hybrid Clay Nanocomposites
JF  - ACS applied materials & interfaces
N2  - This study reports a new class of photocatalytic hybrid clay nanocomposites prepared from low-cost sources (kaolinite clay and Carica papaya seeds) doped with Zn and Cu salts via a solvothermal process. X-ray diffraction analysis suggests that Cu-doping and Cu/Zn-doping introduce new phases into the crystalline structure of Kaolinite clay, which is linked to the reduced band gap of kaolinite from typically between 4.9 and 8.2 eV to 2.69 eV for Cu-doped and 1.5 eV for Cu/Zn hybrid clay nanocomposites (Nisar, J.; Arhammar, C.; Jamstorp, E.; Ahuja, R. Phys. Rev. B 2011, 84, 075120). In the presence of solar light irradiation, Cu- and Cu/Zn-doped nanocomposites facilitate the electron hole pair separation. This promotes the generation of singlet oxygen which in turn improves the water disinfection efficiencies of these novel nanocomposite materials. The nanocomposite materials were further characterized using high-resolution scanning electron microscopy, fluorimetry, therrnogravimetric analysis, and Raman spectroscopy. The breakthrough times of the nanocomposites for a fixed bed mode of disinfection of water contaminated with 2.32 x 10(7) cfu/mL E. coli ATCC 25922 under solar light irradiation are 25 h for Zn-doped, 30 h for Cu-doped, and 35 h for Cu/Zn-doped nanocomposites. In the presence of multidrug and multimetal resistant strains of E. coli, the breakthrough time decreases significantly. Zn-only doped nanocomposites are not photocatalytically active. In the absence of light, the nanocomposites are still effective in decontaminating water, although less efficient than under solar light irradiation. Electrostatic interaction, metal toxicity, and release of singlet oxygen (only in the Cu-doped and Cu/Zn-doped nanocomposites) are the three disinfection mechanisms by which these nanocomposites disinfect water. A regrowth study indicates the absence of any living E. coli cells in treated water even after 4 days. These data and the long hydraulic times (under gravity) exhibited by these nanocomposites during photodisinfection of water indicate an unusually high potential of these nanocomposites as efficient, affordable, and sustainable point-of-use systems for the disinfection of water in developing countries.
KW  - disinfection
KW  - nanocomposite material
KW  - multidrug-resistant Escherichia coli
KW  - water
KW  - reactive oxygen species
Y1  - 2019
U6  - https://doi.org/10.1021/acsami.9b01212
SN  - 1944-8244
SN  - 1944-8252
VL  - 11
IS  - 28
SP  - 25483
EP  - 25494
PB  - American Chemical Society
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Taubert, Andreas
A1  - Stange, Franziska
A1  - Li, Zhonghao
A1  - Junginger, Mathias
A1  - Günter, Christina
A1  - Neumann, Mike
A1  - Friedrich, Alwin
T1  - CuO nanoparticles from the Strongly Hydrated Ionic Liquid Precursor (ILP) Tetrabutylammonium Hydroxide evaluation of the Ethanol Sensing Activity
JF  - ACS applied materials & interfaces
N2  - The sensing potential of CuO nanoparticles synthesized via. precipitation from a water/ionic liquid precursor (ILP) mixture was investigated. The particles have a moderate surface area of 66 m(2)/g after synthesis, which decreases upon thermal treatment to below 5 m(2)/g. Transmission electron microscopy confirms crystal growth upon annealing, likely due to sintering effects. The as-synthesized particles can be used for ethanol sensing. The respective sensors show fast response and recovery times of below 10 s and responses greater than 2.3 at 100 ppm of ethanol at 200 degrees C, which is higher than any CuO-based ethanol sensor described so far.
KW  - ionic liquids
KW  - ionic liquid precursors
KW  - tetrabutylammonium hydroxide
KW  - nanoparticles
KW  - CuO
KW  - gas sensing
Y1  - 2012
U6  - https://doi.org/10.1021/am201427q
SN  - 1944-8244
VL  - 4
IS  - 2
SP  - 791
EP  - 795
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - GEN
A1  - Taubert, Andreas
A1  - Balischewski, Christian
A1  - Hentrich, Doreen
A1  - Elschner, Thomas
A1  - Eidner, Sascha
A1  - Günter, Christina
A1  - Behrens, Karsten
A1  - Heinze, Thomas
T1  - Water-soluble cellulose derivatives are sustainable additives for biomimetic calcium phosphate mineralization
N2  - The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer) contents reach 10% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble) cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 354 
KW  - cellulose
KW  - polyamine
KW  - polyammonium salt
KW  - polycarboxylate
KW  - polyzwitterion
KW  - calcium phosphate
KW  - biomineralization
KW  - brushite
KW  - hydroyxapatite
KW  - biomaterial
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400453
ER  - 
TY  - JOUR
A1  - Taubert, Andreas
A1  - Balischewski, Christian
A1  - Hentrich, Doreen
A1  - Elschner, Thomas
A1  - Eidner, Sascha
A1  - Günter, Christina
A1  - Behrens, Karsten
A1  - Heinze, Thomas
T1  - Water-Soluble Cellulose Derivatives Are Sustainable Additives for Biomimetic Calcium Phosphate Mineralization
JF  - Inorganics : open access journal
N2  - The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer) contents reach 10% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble) cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials.
KW  - cellulose
KW  - polyamine
KW  - polyammonium salt
KW  - polycarboxylate
KW  - polyzwitterion
KW  - calcium phosphate
KW  - biomineralization
KW  - brushite
KW  - hydroyxapatite
KW  - biomaterial
Y1  - 2016
U6  - https://doi.org/10.3390/inorganics4040033
SN  - 2304-6740
VL  - 4
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Shkilnyy, Andriy
A1  - Schöne, Stefanie
A1  - Rumplasch, Claudia
A1  - Uhlmann, Annett
A1  - Hedderich, Annett
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - Calcium phosphate mineralization with linear poly(ethylene imine) a time-resolved study
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - We have earlier shown that linear poly(ethylene imine) (LPEI) is an efficient growth modifier for calcium phosphate mineralization from aqueous solution (Shkilnyy et al., Langmuir, 2008, 24 (5), 2102). The current study addresses the growth process and the reason why LPEI is such an effective additive. To that end, the solution pH and the calcium and phosphate concentrations were monitored vs. reaction time using potentiometric, complexometric, and photometric methods. The phase transformations in the precipitates and particle morphogenesis were analyzed by X-ray diffraction and transmission electron microscopy, respectively. All measurements reveal steep decreases of the pH, calcium, and phosphate concentrations along with a rapid precipitation of brushite nanoparticles early on in the reaction. Brushite transforms into hydroxyapatite (HAP) within the first 2 h, which is much faster than what is reported, for example, for calcium phosphate precipitated with poly(acrylic acid). We propose that poly(ethylene imine) acts as a proton acceptor (weak buffer), which accelerates the transformation from brushite to HAP by taking up the protons that are released from the calcium phosphate precipitate during the phase transformation.
KW  - Calcium phosphate
KW  - Polyethylene imine
KW  - Mineralization
KW  - Kinetics
Y1  - 2011
U6  - https://doi.org/10.1007/s00396-011-2403-2
SN  - 0303-402X
VL  - 289
IS  - 8
SP  - 881
EP  - 888
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Scott, James
A1  - Muhling, Janet
A1  - Fletcher, Ian
A1  - Billia, Marco
A1  - Palin, J. Michael
A1  - Elliot, Tim
A1  - Günter, Christina
T1  - The relationship of Palaeozoic metamorphism and S-type magmatism on the paleo-Pacific Gondwana margin
JF  - Lithos : an international journal of mineralogy, petrology, and geochemistry
N2  - A massive pulse of granitic magma was rapidly emplaced into the once contiguous West Antarctic and New Zealand segments of the palaeo-Pacific margin of the Gondwana supercontinent at similar to 371 Ma. In New Zealand, these Late Devonian S-type granitoids cover an areal extent of > 3400 km(2), but the tectonic setting for crustal partial melting has remained unclear because most of the exposure represents either emplacement-level, or rocks that have been reworked during Cretaceous orogenesis. New petrologic data indicate that aluminous paragneisses and orthogneisses in the Bonar Range represent a rare portion of Devonian middle crust that preserves evidence for the initiation of crustal melting. The investigated rocks outline the tail of a clockwise P-T path that involved partial melting at peak conditions (similar to 670 degrees C, 5.1 kb), deformation during the immediately following near-isothermal decompression, and then partial re-equilibration under static conditions. Syn- to post-kinematic growth of zoned monazite establishes the timing of recrystallisation to a similar to 16 Ma period that began at 373.4 +/- 4.1 Ma. This age overlaps with the initiation of regional Karamea S-type granitic magmatism. Although estimated metamorphic conditions were insufficient for large amounts of melt to have been produced from Bonar Range pelites (calculated melt volumes are <10%), they do provide evidence consistent with widespread heating and partial melting in the deeper crust. This heating episode was contemporaneous with partial melting in Fiordland (New Zealand) and West Antarctica, although Mesozoic thermal and deformational events complicate the Palaeozoic record in both those areas. Nevertheless, the apparent 1000 s km of along-strike crustal partial melting indicates that a continental-scale tectonic plate margin re-organisation took place at this time. The cause in the New Zealand segment was most likely, but not unequivocally, an extensional tectonic regime with an elevated geothermal gradient caused by conductive heating from a shallowed lithospheric mantle.
KW  - Geothermobarometric P-T
KW  - Monazite growth
KW  - Palaeozoic metamorphism New Zealand
KW  - Gondwana
Y1  - 2011
U6  - https://doi.org/10.1016/j.lithos.2011.09.008
SN  - 0024-4937
VL  - 127
IS  - 3-4
SP  - 522
EP  - 534
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Scott, James M.
A1  - Konrad-Schmolke, Matthias
A1  - O'Brien, Patrick J.
A1  - Günter, Christina
T1  - High-T, low-P formation of rare olivine-bearing symplectites in variscan eclogite
JF  - Journal of petrology
N2  - Extremely rare veinlets and reaction textures composed of symplectites of olivine (similar to Fo(43-55)) + plagioclase +/- spinel +/- ilmenite, associated with more common pyroxene + plagioclase and amphibole + plagioclase varieties, are preserved within eclogites and garnet pyroxenites in the Moldanubian Zone of the Bohemian Massif. Thermodynamic modelling integrated with conventional geothermometry conducted on an eclogite reveals that the symplectite-forming stage occurred at high T (similar to 850 degrees C) and low P (< 6 and > 2 center dot 5 kbar). The development of the different symplectite types reflects reactions that took place in micro-scale domains. The breakdown of high-P garnet controlled the formation of olivine-bearing and amphibole + plagioclase symplectites, whereas breakdown of high-P omphacite led to formation of pyroxene + plagioclase symplectites. In addition, post-eclogite facies but pre-symplectite stage porphyroblastic amphibole and phlogopite were also replaced by olivine-bearing symplectites. Material transfer calculations and thermodynamic modelling indicate that the formation of different symplectite types was linked despite their different bulk compositions. For example, the olivine-bearing symplectites gained Fe +/- Mg, whereas adjacent amphibole + plagioclase and pyroxene + plagioclase symplectites show losses in Fe and Mg; Al, Si and Ca were also variably exchanged. The olivine-bearing symplectites were particularly sensitive to Na despite the small concentration of this element. In eclogites where Na was readily available, the plagioclase composition in the olivine-bearing symplectites shifted from pure anorthite to bytownite, with the less calcic feldspar partitioning Si and inhibiting the formation of orthopyroxene. This regional high-T, low-P granulite-facies symplectite overprint may have been caused by advective heat loss from rapidly exhumed high-T, high-P granulitic bodies (Gfohl Unit) that were emplaced into and over the middle crust (Monotonous and Varied Series) during Carboniferous continent-continent collision.
KW  - olivine
KW  - symplectite
KW  - eclogite
KW  - thermodynamics
KW  - Variscan
Y1  - 2013
U6  - https://doi.org/10.1093/petrology/egt015
SN  - 0022-3530
SN  - 1460-2415
VL  - 54
IS  - 7
SP  - 1375
EP  - 1398
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - GEN
A1  - Schneider, Matthias
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - Co-deposition of a hydrogel/calcium phosphate hybrid layer on 3D printed poly(lactic acid) scaffolds via dip coating
BT  - Towards automated biomaterials fabrication
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1057 
KW  - 3D printing
KW  - dip-coating
KW  - poly(lactic acid)
KW  - PLA
KW  - calcium phosphate
KW  - gelatin
KW  - chitosan
KW  - hydrogel
KW  - calcium phosphate hybrid material
KW  - biomaterials
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474427
SN  - 1866-8372
IS  - 1057
ER  - 
TY  - JOUR
A1  - Schneider, Matthias
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - Co-deposition of a hydrogel/calcium phosphate hybrid layer on 3D printed poly(lactic acid) scaffolds via dip coating
BT  - Towards Automated Biomaterials Fabrication
JF  - Polymers
N2  - 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.
KW  - 3D printing
KW  - dip-coating
KW  - poly(lactic acid)
KW  - PLA
KW  - calcium phosphate
KW  - gelatin
KW  - chitosan
KW  - hydrogel
KW  - calcium phosphate hybrid material
KW  - biomaterials
Y1  - 2018
U6  - https://doi.org/10.3390/polym10030275
SN  - 2073-4360
VL  - 10
IS  - 3
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Salama, Ahmed
A1  - Neumann, Mike
A1  - Günter, Christina
A1  - Taubert, Andreas
T1  - Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials
JF  - Beilstein journal of nanotechnology
N2  - 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.
KW  - biomineralization
KW  - calcium phosphate
KW  - carbohydrates
KW  - cellulose
KW  - hybrid materials
KW  - ionic liquid
Y1  - 2014
U6  - https://doi.org/10.3762/bjnano.5.167
SN  - 2190-4286
VL  - 5
SP  - 1553
EP  - 1568
PB  - Beilstein-Institut zur Förderung der Chemischen Wissenschaften
CY  - Frankfurt, Main
ER  - 
TY  - JOUR
A1  - Pereira, Rui F. P.
A1  - Zehbe, Kerstin
A1  - Günter, Christina
A1  - dos Santos, Tiago
A1  - Nunes, Silvia C.
A1  - Almeida Paz, Filipe A.
A1  - Silva, Maria M.
A1  - Granja, Pedro L.
A1  - Taubert, Andreas
A1  - de Zea Bermudez, Verónica
T1  - Ionic liquid-assisted synthesis of mesoporous silk fibroin/silica hybrids for biomedical applications
JF  - ACS Omega
N2  - 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.
Y1  - 2018
U6  - https://doi.org/10.1021/acsomega.8b02051
SN  - 2470-1343
VL  - 3
IS  - 9
SP  - 10811
EP  - 10822
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - GEN
A1  - Olatunji, Akinade S.
A1  - Kolawole, Tesleem O.
A1  - Oloruntola, Moroof
A1  - Günter, Christina
T1  - Evaluation of pollution of soils and particulate matter around metal recycling factories in Southwestern Nigeria
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Background. Metal recycling factories (MRFs) have developed rapidly in Nigeria as recycling policies have been increasingly embraced. These MRFs are point sources for introducing potentially toxic elements (PTEs) into environmental media. Objectives. The aim of this study was to determine the constituents (elemental and mineralogy) of the wastes (slag and particulate matter, (PM)) and soils around the MRFs and to determine the level of pollution within the area. Methods. Sixty samples (30 slag samples, 15 soil samples and 15 PM samples) were collected for this study. The soils, slag and PM samples were analyzed for elemental constituents using inductively coupled plasma optical emission spectrometry. Mineralogy of the PM was determined using scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), and soil mineralogy was determined by an X-ray diffractometer (XRD). Results. The results of the soil analyses revealed the following concentrations for the selected metals in mg/kg include lead (Pb) (21.0-2399.0), zinc (Zn) (56.0-4188.0), copper (Cu) (10.0-1470.0), nickel (Ni) (6.0-215.0), chromium (Cr) (921.0-1737.0) and cadmium (Cd) (below detectable limit (Bdl)-18.1).  For the slags the results were Pb (68.0-.333.0), Zn (1364.0-3062), Cu (119.0-1470.0), Ni (12.0-675.0), Cr (297-1737) and Cd (Bdl-15.8). The results in µg/g for the metal analysis in PM were Pb (4.6-160.0), Zn (18.0-471.0), Cu (2.5-11.0), Ni (0.8-4.2), and Cr (2.5-11.0), while Cd was undetected. The slags are currently utilized for filling the foundations of buildings and roads, providing additional pathways for the introduction of PTEs into the environment from the suspended materials generated from mechanical breakdown of the slags. Conclusions. The MRFs were found to have impacted the quality of environmental media through the introduction of PTEs, impairing soil quality, in addition to PM, which can have detrimental health consequences. Further studies on the health implications of these pollutants and their impacts on human health are needed. Competing Interests. The authors declare no competing financial interests
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1074 
KW  - potentially toxic elements
KW  - metal recycling plants
KW  - slags
KW  - pollution indices
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-471560
SN  - 1866-8372
IS  - 1074
SP  - 20
EP  - 30
ER  - 
TY  - JOUR
A1  - Olatunji, Akinade S.
A1  - Kolawole, Tesleem O.
A1  - Oloruntola, Moroof
A1  - Günter, Christina
T1  - Evaluation of pollution of soils and particulate matter around metal recycling factories in Southwestern Nigeria
JF  - Journal of health and pollutuin
N2  - Background. Metal recycling factories (MRFs) have developed rapidly in Nigeria as recycling policies have been increasingly embraced. These MRFs are point sources for introducing potentially toxic elements (PTEs) into environmental media. Objectives. The aim of this study was to determine the constituents (elemental and mineralogy) of the wastes (slag and particulate matter, (PM)) and soils around the MRFs and to determine the level of pollution within the area. Methods. Sixty samples (30 slag samples, 15 soil samples and 15 PM samples) were collected for this study. The soils, slag and PM samples were analyzed for elemental constituents using inductively coupled plasma optical emission spectrometry. Mineralogy of the PM was determined using scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), and soil mineralogy was determined by an X-ray diffractometer (XRD). Results. The results of the soil analyses revealed the following concentrations for the selected metals in mg/kg include lead (Pb) (21.0-2399.0), zinc (Zn) (56.0-4188.0), copper (Cu) (10.0-1470.0), nickel (Ni) (6.0-215.0), chromium (Cr) (921.0-1737.0) and cadmium (Cd) (below detectable limit (Bdl)-18.1). For the slags the results were Pb (68.0-.333.0), Zn (1364.0-3062), Cu (119.0-1470.0), Ni (12.0-675.0), Cr (297-1737) and Cd (Bdl-15.8). The results in mu g/g for the metal analysis in PM were Pb (4.6-160.0), Zn (18.0-471.0), Cu (2.5-11.0), Ni (0.8-4.2), and Cr (2.5-11.0), while Cd was undetected. The slags are currently utilized for filling the foundations of buildings and roads, providing additional pathways for the introduction of PTEs into the environment from the suspended materials generated from mechanical breakdown of the slags. Conclusions. The MRFs were found to have impacted the quality of environmental media through the introduction of PTEs, impairing soil quality, in addition to PM, which can have detrimental health consequences. Further studies on the health implications of these pollutants and their impacts on human health are needed. Competing Interests. The authors declare no competing financial interests
KW  - potentially toxic elements
KW  - metal recycling plants
KW  - slags
KW  - pollution indices
Y1  - 2017
U6  - https://doi.org/10.5696/2156-9614-8.17.20
SN  - 2156-9614
VL  - 8
IS  - 17
SP  - 20
EP  - 30
PB  - Blacksmith Institute and Pure Earth
CY  - New York
ER  - 
TY  - JOUR
A1  - Mai, Tobias
A1  - Rakhmatullina, Ekaterina
A1  - Bleek, Katrin
A1  - Boye, Susanne
A1  - Yuan, Jiayin
A1  - Voelkel, Antje
A1  - Graewert, Marlies
A1  - Cheaib, Zeinab
A1  - Eick, Sigrun
A1  - Günter, Christina
A1  - Lederer, Albena
A1  - Lussi, Adrian
A1  - Taubert, Andreas
T1  - Poly(ethylene oxide)-b-poly(3-sulfopropyl methacrylate) block copolymers for calcium phosphate mineralization and biofilm inhibition
JF  - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences
N2  - 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.
Y1  - 2014
U6  - https://doi.org/10.1021/bm500888q
SN  - 1525-7797
SN  - 1526-4602
VL  - 15
IS  - 11
SP  - 3901
EP  - 3914
PB  - American Chemical Society
CY  - Washington
ER  -