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Hamburg, Germany

The Hamburg University of Technology is one of the youngest universities in Germany as well as among those who have achieved popularity in a short time.The university was founded in 1978 and in 1982/83 lecturing followed. Around 100 senior lecturers/professors and 1,150 members of staff work at the TUHH. With an average of 5,000 students the TUHH offers a high ratio of staff to students.It is located in Harburg, a district in the south of Hamburg. Wikipedia.

Schneider G.A.,TU Hamburg - Harburg
Journal of the Mechanics and Physics of Solids | Year: 2013

An energy release rate based fracture model is presented, which is able to describe unstable dielectric breakdown of ceramic and polymer insulators. The electric field and electrostatic energy of an electrically conducting filament within a spheroidal surface electrode is calculated. As space charge injection is allowed the electric field singularity at the electrical conducting filament is reduced. As a consequence it is possible to solve the electrostatic problem even for filaments where the diameter is reduced to zero and the energy release rate can be formulated only as a function of the filament length. The presented energy release rate together with the formulation of a dielectric breakdown criterion allows understanding the experimentally measured one over square root sample thickness dependence and the pronounced scatter of the measured dielectric breakdown strength. © 2012 Elsevier Ltd. All rights reserved.

Kakuchi R.,TU Hamburg - Harburg
Angewandte Chemie - International Edition | Year: 2014

More participants, yet efficient reactions: Multicomponent reactions (MCRs) have found application in polymer chemistry both in the synthesis of multifunctional monomers and in post-polymerization modification. Examples include the Passerini three-component reaction, the Ugi four-component reaction, and the copper-catalyzed MCR (see scheme). Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

It is commonly accepted that the combination of the anisotropic shape and nanoscale dimensions of the mineral constituents of natural biological composites underlies their superior mechanical properties when compared to those of their rather weak mineral and organic constituents. Here, we show that the self-assembly of nearly spherical iron oxide nanoparticles in supercrystals linked together by a thermally induced crosslinking reaction of oleic acid molecules leads to a nanocomposite with exceptional bending modulus of 114 GPa, hardness of up to 4 GPa and strength of up to 630 MPa. By using a nanomechanical model, we determined that these exceptional mechanical properties are dominated by the covalent backbone of the linked organic molecules. Because oleic acid has been broadly used as nanoparticle ligand, our crosslinking approach should be applicable to a large variety of nanoparticle systems. © 2016 Nature Publishing Group

Kaminsky W.,TU Hamburg - Harburg
Macromolecules | Year: 2012

The discovery of methylaluminoxane (MAO) was the start for investigations and innovations of new classes of highly active olefin polymerization catalysts. Different transition metal complexes together with MAO as cocatalyst allow the synthesis of polymers with a highly defined microstructure, tacticity, and stereoregularity as well as new cycloolefin, long chain branched, or blocky copolymers with excellent properties. These new polyolefins could not be obtaind with such a purity before by Ziegler-Natta catalysts. The single site catalyst character of metallocene and other transition metal complexes activated by MAO leads to a better understanding of the mechanism of the olefin polymerization. © 2012 American Chemical Society.

Jochum F.D.,University of Mainz | Jochum F.D.,Catholic University of Louvain | Theato P.,Seoul National University | Theato P.,TU Hamburg - Harburg
Chemical Society Reviews | Year: 2013

Stimuli-responsive polymers have been attracting great interest within the scientific community for several decades. The unique feature to respond to small changes in the environmental conditions has made this class of materials very promising for several applications in the field of nanoscience, nanotechnology and nanomedicine. So far, several different chemical, physical or biochemical stimuli have been investigated within natural or synthetic polymers. Very interesting and appealing seems to be the combination of several stimuli to tune the properties of these materials in manifold ways. Within this present review, we want to highlight the recent progress in the field of synthetic stimuli-responsive polymers combining temperature and light responsiveness. © 2013 The Royal Society of Chemistry.

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