@article{GruberChakravartyBaehtzetal.2011, author = {Gruber, W. and Chakravarty, S. and Baehtz, C. and Leitenberger, Wolfram and Bruns, M. and Kobler, A. and K{\"u}bel, Christian and Schmidt, H.}, title = {Strain relaxation and vacancy creation in thin platinum films}, series = {Physical review letters}, volume = {107}, journal = {Physical review letters}, number = {26}, publisher = {American Physical Society}, address = {College Park}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.107.265501}, pages = {5}, year = {2011}, abstract = {Synchrotron based combined in situ x-ray diffractometry and reflectometry is used to investigate the role of vacancies for the relaxation of residual stress in thin metallic Pt films. From the experimentally determined relative changes of the lattice parameter a and of the film thickness L the modification of vacancy concentration and residual strain was derived as a function of annealing time at 130 degrees C. The results indicate that relaxation of strain resulting from compressive stress is accompanied by the creation of vacancies at the free film surface. This proves experimentally the postulated dominant role of vacancies for stress relaxation in thin metal films close to room temperature.}, language = {en} } @article{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 biomimetric calcium phosphate nanofibers}, doi = {10.1039/c3ra23348k}, 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} } @article{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}, series = {RSC Advances}, volume = {3}, journal = {RSC Advances}, number = {28}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/c3ra23348k}, 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} } @article{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 Szabo, Dorothee Vinga and Meinusch, Rafael and Bermudez, Veronica de Zea and Taubert, Andreas}, title = {Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting}, series = {Beilstein journal of nanotechnology}, volume = {9}, 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.9.21}, pages = {187 -- 204}, year = {2018}, abstract = {The synthesis, structure, and photocatalytic water splitting performance of two new titania (TiO2)/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 TiO2 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{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{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} }