TY - CONF A1 - Maskos, Michael T1 - Degradation of Polymers at BAM Federal Institute for Materials Research and Testing, Berlin T2 - 459th WE-Heraeus-Seminar CY - Bad Honnef, Germany DA - 2010-05-30 PY - 2010 AN - OPUS4-21432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kocun, M. A1 - Mueller, W. A1 - Maskos, Michael A1 - Mey, I. A1 - Geil, B. A1 - Steinem, C. A1 - Janshoff, A. T1 - Viscoelasticity of pore-spanning polymer membranes derived from giant polymersomes N2 - We show how the viscoelastic properties of membranes formed from poly(butadiene)-block-poly(ethylene oxide) (PB130-b-PEO66) block copolymers can be locally accessed by atomic force microscopy. Polymer membranes are spread on microstructured porous silicon substrates from PB130-b-PEO66 vesicles by decreasing the osmotic pressure of the solution. Local viscoelastic properties of the pore-spanning polymer membranes were obtained from site-specific indentation experiments. Elastic moduli of these membranes were in the order of few MPa, while the elastic moduli of cross-linked membranes considerably increased to few GPa. Furthermore, the energy dissipation and velocity dependence of the hysteresis between indentation and relaxation were quantified and compared with a modified Kelvin-Voigt model. Relaxation times were in the order of hundreds of milliseconds explaining why the stiffness of the membrane increases with increasing indentation velocity. PY - 2010 DO - https://doi.org/10.1039/b924650a SN - 1744-683X VL - 6 SP - 2508 EP - 2516 PB - RSC Publ. CY - Cambridge AN - OPUS4-21553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maskos, Michael T1 - Polymeric Nanoparticles: Chances and Challenges T2 - Tag der Chemie CY - Berlin, Germany DA - 2010-06-16 PY - 2010 AN - OPUS4-21523 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tonhauser, C. A1 - Wilms, D. A1 - Wurm, F. A1 - Berger-Nicoletti, E. A1 - Maskos, Michael A1 - Löwe, H. A1 - Frey, H. T1 - Multihydroxyl-functional polystyrenes in continuous flow N2 - We describe the synthesis of end-functionalized polystyrenes by living anionic polymerization in a microstructured reactor via termination by acetal-protected functional epoxides. Initiation of styrene polymerization by alkyllithium takes place in a micromixing device with efficient heat and mass transfer properties. A newly developed continuous polymerization-termination sequence enabled quantitative functionalization of the living carbanions by nucleophilic displacement with different, specifically designed glycidyl ethers (ethoxy ethyl glycidyl ether (EEGE), 1,2-isopropylidene glyceryl glycidyl ether (IGG), and trans-2-phenyl-1,3-dioxane glycidyl ether (PDGE)). Upon acidic hydrolysis the end-capped polystyrenes release multiple hydroxyl groups (2-3) at the chain end. Temperature and flow rates have been varied to control molecular weights and to optimize the reaction conditions for maximum polymerization and termination efficiency. The polymers were analyzed in detail using NMR spectroscopy, size exclusion chromatography (SEC), and MALDI-ToF-MS. Molecular weights of the samples prepared ranged between 1800 and 9000 g/mol. For all of the novel termination agents full termination was confirmed by MALDI-ToF MS. The approach presented is applicable for a large variety of monomers that are polymerizable by carbanionic polymerization. PY - 2010 DO - https://doi.org/10.1021/ma902849r SN - 0024-9297 SN - 1520-5835 VL - 43 IS - 13 SP - 5582 EP - 5588 PB - American Chemical Society CY - Washington, DC AN - OPUS4-21710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maskos, Michael T1 - Interaction of Cells with Biologically Functionalized, Multicompartment Polyorganosiloxane Nanoparticles T2 - GKSS Workshop "Structural aspects of biocompatible ferrofluids: stabilization, properties control and application" CY - Geesthacht, Germany DA - 2010-01-28 PY - 2010 AN - OPUS4-20865 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maskos, Michael T1 - Micromixers Offering New Process Windows for the Controlled Synthesis of Polymeric and Polymer-coated Nanoparticles T2 - 11th International Conference on Microreaction Technology (IMRETT 11) CY - Kyoto, Japan DA - 2010-03-08 PY - 2010 AN - OPUS4-21014 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maskos, Michael T1 - Multifunctional, Polymeric Nanoparticles in Biological Environments T2 - Seminarreihe des BCRT CY - Berlin, Germany DA - 2010-05-04 PY - 2010 AN - OPUS4-21273 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maskos, Michael T1 - Topologically controlled Inter-Polyelectrolyte-Complexes T2 - 8th International Symposium on Polyelectrolytes 2010 (ISP 2010) CY - Shanghai, China DA - 2010-11-14 PY - 2010 AN - OPUS4-22443 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krohne, Korinna A1 - Duschner, S. A1 - Störkle, D. A1 - Schmidt, M. A1 - Maskos, Michael T1 - Topologically controlled inter-polyelectrolyte complexes between molecular bottlebrushes and dendrimers N2 - The complexation of a cylindrical polyelectrolyte–brush-surfactant complex (PMMPSS–C12) and an oppositely charged generation-5 PAMAM dendrimer (G5-PAMAM) in methanol (MeOH) leads to kinetically controlled formation of interpolyelectrolyte complexes. In contrast, the complexation of the same starting materials in solvents with higher dielectric constant such as dimethylformamide (DMF) or N-methylformamide (NMF) results in the formation of topologically controlled complexes of cylindrical morphology. The composition of the complexes is analyzed by static and dynamic light scattering (SLS, DLS) in solution and atomic force microscopy (AFM) after spin-casting the complexes onto mica. The analyzed complexes seem to consist of one PMMPSS–C12 molecule and, with increasing G5-PAMAM content, of an increasing number of G5-PAMAM dendrimers. KW - Macromolecules PY - 2010 DO - https://doi.org/10.1021/ma101630h SN - 0024-9297 SN - 1520-5835 VL - 43 IS - 20 SP - 8645 EP - 8650 PB - American Chemical Society CY - Washington, DC AN - OPUS4-22447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Utech, S. A1 - Scherer, Christian A1 - Krohne, K. A1 - Carrella, L. A1 - Rentschler, E. A1 - Gasi, T. A1 - Ksenofontov, V. A1 - Felser, C. A1 - Maskos, Michael T1 - Magnetic polyorganosiloxane core-shell nanoparticles: Synthesis, characterization and magnetic fractionation N2 - Here, we present the synthesis, characterization and magnetic separation of magnetic polyorganosiloxane nanoparticles. Magnetic iron oxide nanoparticles with average particle radii of 3.2 nm had been synthesized by a simple coprecipitation process of iron(II) and iron(III) salt in basic solution. Afterwards, the particles were successfully incorporated into a polyorganosiloxane network via a polycondensation reaction of trimethoxymethylsilane (T), diethoxydimethylsilane (D) and the functional monomer (chloromethylphenyl)trimethoxysilane (ClBz-T) in aqueous dispersion. A core–shell system was chosen to increase the flexibility of the system concerning size, composition and functionalization possibilities. The magnetic nanocapsules with particle radii below 60 nm were separated from non-magnetic material with a high effectiveness by the use of commercially available separation columns which are commonly used for isolation of microbeads and subsequently characterized via transmission electron microscopy (TEM), asymmetrical flow field-flow fractionation (AF-FFF), superconducting quantum interference device (SQUID) and Mössbauer spectroscopy. KW - Nanoparticle KW - Magnetic KW - Encapsulation KW - Polyorganosiloxane KW - Magnetic separation PY - 2010 DO - https://doi.org/10.1016/j.jmmm.2010.06.056 SN - 0304-8853 VL - 322 IS - 21 SP - 3519 EP - 3526 PB - Elsevier CY - Amsterdam AN - OPUS4-22248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scherer, Christian A1 - Utech, S. A1 - Scholz, S. A1 - Noskov, S. A1 - Kindervater, P. A1 - Graf, R. A1 - Thünemann, Andreas A1 - Maskos, Michael T1 - Synthesis, characterization and fine-tuning of bimodal poly(organosiloxane) nanoparticles N2 - The acid catalyzed sol–gel type synthesis of polyorganosiloxane core-shell nanoparticles with removable PDMS core in aqueous dispersion leads to the inherent formation of a bimodal size distribution with smaller spheres having approximately 26 nm radii and larger nanoparticles with 60 nm in radius. The origin of the self-organized bimodality is investigated and finally attributed to a combination of stabilization of the growing particles due to i) a miniemulsion-type stabilization by the ultrahydrophobe PDMS and ii) by surface co-stabilization by the employed surfactant. The significant influence of temperature, pH, stirrer speed and amount of the surfactant on the particle sizes allows for the design and fine-tuning of different nanoparticles sizes and distributions. KW - Nanoparticles KW - Polyorganosiloxane KW - Field-flow fractionation (FFF) PY - 2010 DO - https://doi.org/10.1016/j.polymer.2010.09.065 SN - 0032-3861 SN - 1873-2291 VL - 51 IS - 23 SP - 5432 EP - 5439 PB - Springer CY - Berlin AN - OPUS4-22476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -