Dresden 2009 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 39: POSTERS Colloids and Liquids
CPP 39.2: Poster
Donnerstag, 26. März 2009, 17:00–19:30, P3
The volume phase transition of thermoresponsive core-shell microgels investigated by small angle neutron scattering — •Matthias Karg1, Stefan Wellert2, Yvonne Hertle3, and Thomas Hellweg3 — 1TU Berlin, Germany — 2Helmoltz-Zentrum Berlin, Germany — 3Universität Bayreuth, Germany
Organic/inorganic hybrids attracted much interest within the last decade, since they can combine the properties of both components. Such composites can benefit e.g. from the thermoresponsive character of a polymer component and optical, catalytic or magnetic properties stemming from the inorganic material. Of special interest are hybrids with a core-shell structure, because they have a well-defined topology and hence are interesting for different physical investigations and applications like photonic materials.
We present here responsive core-shell microgels, with silica nanoparticles of different sizes as cores. Imaging techniques were used to study the structure of these hybrids regarding their core-shell topology. The volume phase transition (VPT) of the polymer shell was studied by dynamic light scattering and, focussing on the local length-scale, by small angle neutron scattering (SANS). SANS allowed to determine the correlation length of the polymer network. The scaling behavior of the correlation length was studied by SANS measurements in the vicinity of the VPT temperature. By contrast matching experiments the core size and polydispersity was investigated in-situ[1].
[1] M. Karg, S. Wellert, I. Pastoriza-Santos, A. Lapp, L. M. Liz-Marzán, T. Hellweg, Phys. Chem. Chem. Phys., 2008, 10, 6708-6716