TY - CONF A1 - Scherer, Christian A1 - Noskov, S. A1 - Schupp, W. A1 - Maskos, Michael T1 - Influence of Ionic Strength and different Electrolytes on the Retention in AF-FFF T2 - 239th American Chemical Soyciety National Meeting T2 - 239th American Chemical Soyciety National Meeting CY - San Francisco, CA, USA DA - 2010-03-21 PY - 2010 AN - OPUS4-21039 LA - deu 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 JF - Journal of magnetism and magnetic materials 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 - Noskov, S. A1 - Utech, S. A1 - Bantz, C. A1 - Mueller, W. A1 - Krohne, K. A1 - Maskos, M. T1 - Characterization of polymer nanoparticles by asymmetrical flow field flow fractionation (AF-FFF) JF - Journal of nanoscience and nanotechnology KW - Nanoparticles KW - Block copolymersm maghemite KW - Core-shell structure KW - Polyorganosiloxane PY - 2010 DO - https://doi.org/10.1166/jnn.2010.2973 SN - 1533-4880 VL - 10 IS - 10 SP - 6834 EP - 6839 PB - American Scientific Publ. CY - Stevenson Ranch, Calif., USA AN - OPUS4-21979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scherer, Christian A1 - Maskos, Michael A1 - Thünemann, Andreas T1 - Synthesis of hollow poly(organosiloxane) nanoparticles soluble in aqueous media T2 - 238th National Meeting and Exposition (ACS) T2 - 238th National Meeting and Exposition (ACS) CY - Washington, D.C., USA DA - 2009-08-16 PY - 2009 AN - OPUS4-20002 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scherer, Christian A1 - Thünemann, Andreas A1 - Maskos, Michael T1 - Synthesis and Characterization of polyorganosiloxane particles T2 - Frontiers in Polymer Science Anniversary Symposium T2 - Frontiers in Polymer Science Anniversary Symposium CY - Mainz, Germany DA - 2009-06-07 PY - 2009 AN - OPUS4-20001 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noskov, Sergey A1 - Scherer, Christian A1 - Maskos, Michael A1 - Thünemann, Andreas T1 - Determination of Hamaker constants of polymeric nanoparticles in organic solvents by asymmetrical flow field-flow fractionation JF - Journal of chromatography A N2 - Interaction forces between all objects are either of repulsive or attractive nature. Concerning attractive interactions, the determination of dispersion forces are of special interest since they appear in all colloidal systems and have a crucial influence on the properties and processes in these systems. One possibility to link theory and experiment is the description of the London–Van der Waals forces in terms of the Hamaker constant, which leads to the challenging problem of calculating the van der Waals interaction energies between colloidal particles. Hence, the determination of a Hamaker constant for a given material is needed when interfacial phenomena such as adhesion are discussed in terms of the total potential energy between particles and substrates. In this work, the asymmetrical flow field-flow fractionation (AF-FFF) in combination with a Newton algorithm based iteration process was used for the determination of Hamaker constants of different nanoparticles in toluene. KW - Hamaker constant KW - Asymmetrical flow field flow fractionation KW - Lifshitz KW - Van der Waals KW - London KW - Thermodynamic KW - Interaction PY - 2013 DO - https://doi.org/10.1016/j.chroma.2012.12.001 SN - 0021-9673 VL - 1274 SP - 151 EP - 158 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-27625 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 JF - Polymer 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 -