@article{HaaseMantionGrafetal.2012, author = {Haase, A. and Mantion, A. and Graf, P. and Plendl, J. and Th{\"u}nemann, Andreas F. and Meier, Wolfgang P. and Taubert, Andreas and Luch, A.}, title = {A novel type of silver nanoparticles and their advantages in toxicity testing in cell culture systems}, series = {Archives of toxicology : official journal of EUROTOX}, volume = {86}, journal = {Archives of toxicology : official journal of EUROTOX}, number = {7}, publisher = {Springer}, address = {Heidelberg}, issn = {0340-5761}, doi = {10.1007/s00204-012-0836-0}, pages = {1089 -- 1098}, year = {2012}, abstract = {Silver nanoparticles (SNPs) are among the most commercialized nanoparticles worldwide. Often SNP are used because of their antibacterial properties. Besides that they possess unique optic and catalytic features, making them highly interesting for the creation of novel and advanced functional materials. Despite its widespread use only little data exist in terms of possible adverse effects of SNP on human health. Conventional synthesis routes usually yield products of varying quality and property. It thus may become puzzling to compare biological data from different studies due to the great variety in sizes, coatings or shapes of the particles applied. Here, we applied a novel synthesis approach to obtain SNP of well-defined colloidal and structural properties. Being stabilized by a covalently linked small peptide, these particles are nicely homogenous, with narrow size distribution, and form monodisperse suspensions in aqueous solutions. We applied these peptide-coated SNP in two different sizes of 20 or 40 nm (Ag20Pep and Ag40Pep) and analyzed responses of THP-1-derived human macrophages while being exposed against these particles. Gold nanoparticles of similar size and coating (Au20Pep) were used for comparison. The cytotoxicity of particles was assessed by WST-1 and LDH assays, and the uptake into the cells was confirmed via transmission electron microscopy. In summary, our data demonstrate that this novel type of SNP is well suited to serve as model system for nanoparticles to be tested in toxicological studies in vitro.}, language = {en} } @article{FokouMeier2010, author = {Fokou, Patrice A. and Meier, Michael A. R.}, title = {Studying and suppressing olefin isomerization side reactions during ADMET polymerizations}, issn = {1022-1336}, doi = {10.1002/marc.200900678}, year = {2010}, abstract = {Olefin isomerization side reactions that occur during ADMET polymerizations were studied by preparing polyesters via ADMET and subsequently degrading these polyesters via transesterification with methanol. The resulting diesters, representing the repeating units of the previously prepared polyesters, were then analyzed by GC-MS. This strategy allowed quantification of the amount of olefin isomerization that took place during ADMET polymerization with second generation ruthenium metathesis catalysts. In a second step, it was shown that the addition of benzoquinone to the polymerization mixture prevented the olefin isomerization. Therefore, second generation ruthenium metathesis catalysts may now be used for the preparation of well-defined polymers via ADMET with very little isomerization, which was not possible before.}, language = {en} } @article{HermanussenLiebermanSchoenfeldJanewaetal.2012, author = {Hermanussen, Michael and Lieberman, L. S. and Sch{\"o}nfeld Janewa, U. and Scheffler, Christiane and Ghosh, A. and Bogin, Barry and Godina, E. and Kaczmarek, M. and El-Shabrawi, M. and Salama, E. E. and R{\"u}hli, F. J. and Staub, K. and Woitek, U. and Blaha, Pawel and vanBuurren, S. and Lehmann, A. and Satake, T. and Thodberg, H. H. and Jopp, E. and Kirchengast, S. and Tutkuviene, J. and McIntyre, M. H. and Wittwer-Backofen, U. and Boldsen, J. L. and Martin, D. D. and Meier, J.}, title = {Diversity in auxology: between theory and practice Proceedings of the 18th Aschauer Soiree, 13th November 2010}, issn = {0003-5548}, year = {2012}, language = {en} } @book{RiemenschneiderSarkowskyStrohetal.2004, author = {Riemenschneider, Dieter and Sarkowsky, K. and Stroh, S. and Schulze-Engler, F. and Matzke, C. and Meier, A. and Wegner, M. and Stein, Mark and Fischer, J. and Riemenschneider, K.}, title = {Postcolonial theory : the emergence of a critical discourse ; a selected and annotated bibliography}, series = {ZAA Studies : language literature culture}, volume = {17}, journal = {ZAA Studies : language literature culture}, publisher = {Stauffenburg-Verl.}, address = {T{\"u}bingen}, isbn = {3-86057-746-8}, pages = {XiV, 211 S.}, year = {2004}, language = {en} } @article{WebsterMeier2010, author = {Webster, Dean C. and Meier, Michael A. R.}, title = {Polymer libraries : preparation and applications}, issn = {0065-3195}, doi = {10.1007/12_2009_15}, year = {2010}, abstract = {Polymer libraries offer straightforward opportunities for the investigation of structure property relationships and for a more thorough understanding of certain research problems. Furthermore, if combined with high-throughput methods for their preparation as well as screening, they offer the additional advantage of time savings and/or the reduction of experimental efforts. Thus, the herein discussed methods of polymer library preparation and selected literature examples of polymer libraries describe efficient and state-of-the-art methods to tackle difficult research challenges in polymer and materials science.}, language = {en} } @article{TueruencMeier2010, author = {T{\"u}r{\"u}nc, Oguz and Meier, Michael A. R.}, title = {Fatty acid derived monomers and related polymers via Thiol-ene (click) additions}, issn = {1022-1336}, doi = {10.1002/marc.201000291}, year = {2010}, abstract = {Thiol-ene additions of methyl 10-undecenoate, a castor oil derived renewable platform chemical, were studied with the goal of preparing a set of renewable monomers. Good to excellent yields were obtained for these solvent and initiator free thiol-ene additions. The resulting monomers were then polymerized using TBD as a catalyst, to linear as well as hyperbranched polyesters that also contain thio-ether linkages. All thus prepared polymers were fully characterized (NMR, GPC, DSC, and TGA) and the results of these investigations will be discussed within this contribution. The thermal analysis of these polymers revealed melting points in the range from 50 to 71 degrees C. Moreover, no significant weight loss was observed below 300 degrees C.}, language = {en} } @article{DjigoueMeier2009, author = {Djigou{\´e}, Guy Bertrand and Meier, Michael A. R.}, title = {Improving the selectivity for the synthesis of two renewable platform chemicals via olefin metathesis}, issn = {0926-860X}, doi = {10.1016/j.apcata.2009.08.025}, year = {2009}, abstract = {The self-metathesis of methyl 10-undecenoate as well as its cross-metathesis with methyl acrylate was investigated in detail by a systematic variation of the reaction conditions. Unsaturated ;,;-diesters with a chain length of 20 and 12 carbon atoms were thus obtained, respectively. Four different metathesis catalysts were investigated under solvent-free conditions at catalyst loadings ranging from 0.05 mol\% to 1 mol\% and at temperatures ranging from 30 °C to 90 °C. In the case of the self-metathesis reactions quantitative conversions were obtained with all catalysts, but the second generation metathesis catalysts revealed high amounts of olefin isomerization side reactions at higher temperatures. Using a small quantity of the hydrogen acceptor 1,4-benzoquinone, the isomerization process was almost completely suppressed. Thus, the second generation catalysts allowed for high conversions at very low catalyst loadings. For the cross-metathesis reaction, an interesting temperature and catalyst loading dependent selectivity was observed with the second generation catalysts. Moreover, due to these optimizations, we were able to run these cross-metathesis reactions with a 1:1 ratio of the reactants and low catalysts loadings. This is an improvement over described literature procedures. Thus, we report on the detailed investigation of the described self- and cross- metathesis reactions leading to practical and optimized reaction conditions for the synthesis of unsaturated ;,;-diesters monomers from renewable raw materials in an efficient catalytic manner.}, language = {en} } @article{Meier2009, author = {Meier, Michael A. R.}, title = {Metathesis with oleochemicals : new approaches for the utilization of plant oils as renewable resources in polymer science}, issn = {1022-1352}, doi = {10.1002/macp.200900168}, year = {2009}, abstract = {Due to depleting fossil resources, the ever increasing emission of greenhouse gases and toxic waste, as well as the inefficient utilization of our available resources, we have to implement the principles of green chemistry whenever and wherever possible. Plant oils are already the most important renewable resource for the chemical industry. Due to their inherent double-bond functionality, they offer the possibility of being transformed via several very efficient catalytic processes. Especially, new developments in olefin metathesis allow the chemist to directly polymerize or introduce a variety of functional groups to these renewable resources in an efficient manner. Therefore, olefin metathesis with plant-oil-derived fatty acids and their derivatives can contribute to a sustainable development of our future, since this approach has great potential for the substitution of currently used petrochemicals and a variety of value-added chemical intermediates, especially for the polymer industry, can be derived from these resources in a straightforward fashion. This contribution will address and discuss the most recent developments in this field of research.}, language = {en} } @article{deEspinosaMeierRondaetal.2010, author = {de Espinosa, Lucas Montero and Meier, Michael A. R. and Ronda, Juan C. and Galiß, Marina and Cßdiz, Virginia}, title = {Phosphorus-containing renewable polyester-polyols via ADMET polymerization : synthesis, functionalization, and radical crosslinking}, issn = {0887-624X}, doi = {10.1002/Pola.23887}, year = {2010}, abstract = {An alpha,omega-diene containing hydroxyl groups was prepared from plant oil-derived platform chemicals. The acyclic diene metathesis copolymerization (ADMET) of this monomer with a phosphorus-containing alpha,omega-cliene (DOPO II), also plant oil derived, afforded a series of phosphorus containing linear polyesters, which have been fully characterized. The backbone hydroxyls of these polyesters have been acrylated and radically polymerized to produce crosslinked polymers. The thermomechanical and mechanical properties, the thermal stability, and the flame retardancy of these phosphorus-based thermosets have been studied. Moreover, methyl 10-undecenoate has been used as chain stopper in selected ADMET polymerizations to study the effect of the prepolymers' molecular weights on the different properties of the final materials.}, language = {en} } @article{BiermannMetzgerMeier2010, author = {Biermann, Ursula and Metzger, Juergen O. and Meier, Michael A. R.}, title = {Acyclic triene metathesis oligo- and polymerization of high oleic sun flower oil}, issn = {1022-1352}, doi = {10.1002/macp.200900615}, year = {2010}, abstract = {High oleic sunflower oil, a renewable raw material consisting of triglycerides with internal C=C-double bonds, was polymerized via acyclic triene metathesis (ATMET) to highly branched and functionalized polyesters. If the Hoveyda- Grubbs second generation catalyst was used and methyl acrylate was introduced as a chain stopper, the molecular weight of the obtained polymers could be tuned by varying the ratio of the triglyceride and methyl acrylate. Using the first generation Grubbs catalyst for the polymerization of high oleic sunflower oil, no cross-linking was observed, even without the use of a chain stopper. The resulting branched materials were characterized by GPC, H-1 and C-13 NMR, and ESI-MS.}, language = {en} }