@article{ZehbeZehbe2016, author = {Zehbe, Rolf and Zehbe, Kerstin}, title = {Strontium doped poly-epsilon-caprolactone composite scaffolds made by reactive foaming}, series = {The European journal of the history of economic thought}, volume = {67}, journal = {The European journal of the history of economic thought}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0928-4931}, doi = {10.1016/j.msec.2016.05.045}, pages = {259 -- 266}, year = {2016}, abstract = {In the reconstruction and regeneration of bone tissue, a primary goal is to initiate bone growth and to stabilize the surrounding bone. In this regard, a potentially useful component in biomaterials for bone tissue engineering is strontium, which acts as cationic active agent, triggering certain intracellular pathways and acting as so called dual action bone agent which inhibits bone resorption while stimulating bone regeneration. In this study we established a novel processing for the foaming of a polymer (poly-epsilon-caprolactone) and simultaneous chemical reaction of a mixture of calcium and strontium hydroxides to the respective carbonates using supercritical carbon dioxide. The resultant porous composite scaffold was optimized in composition and strontium content and was characterized via different spectroscopic (infrared and Raman spectroscopy, energy dispersive X-ray spectroscopy), imaging (SEM, mu CT), mechanical testing and in vitro methods (fluorescence vital staining, MTT-assay). As a result, the composite scaffold showed good in vitro biocompatibility with partly open pore structure and the expected chemistry. First mechanical testing results indicate sufficient mechanical stability to support future in vivo applications. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @article{ThielZehbeRoeseretal.2013, author = {Thiel, Kerstin and Zehbe, Rolf and R{\"o}ser, Jerome and Strauch, Peter and Enthaler, Stephan and Thomas, Arne}, title = {A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks}, series = {Polymer Chemistry}, volume = {4}, journal = {Polymer Chemistry}, number = {6}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/c2py20947k}, pages = {1848 -- 1856}, year = {2013}, abstract = {A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.}, language = {en} } @article{ThielZehbeRoesneretal.2013, author = {Thiel, Kerstin and Zehbe, Rolf and Roesner, Jer{\^o}m{\´e} and Strauch, Peter and Enthaler, Stephan and Thomas, Arne}, title = {A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks}, doi = {10.1039/C2PY20947K}, year = {2013}, abstract = {A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.}, language = {en} } @misc{ThielZehbeRoeseretal.2013, author = {Thiel, Kerstin and Zehbe, Rolf and Roeser, Jer{\^o}m{\´e} and Strauch, Peter and Enthaler, Stephan and Thomas, Arne}, title = {A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-95118}, pages = {1848 -- 1856}, year = {2013}, abstract = {A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.}, language = {en} }