Dresden 2011 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 36: Poster: Nanoparticles and Composite Materials
CPP 36.7: Poster
Mittwoch, 16. März 2011, 17:00–19:00, P2
Segment density and coil dimensions of polymer chains anchored to solid surfaces — •Chang Jong Kim1, Tinka Spehr1, Bernd Stühn1, Markus Mazurowski2, Katrin Sondergeld2, Roland Klein2, and Matthias Rehahn2 — 1TU Darmstadt,Experimental Condensed Matter Physics — 2TU Darmstadt,Ernst-Berl-Institute for Technical and Macromolecular Chemistry
Polymer chains tethered onto curved substrates show different conformation compared to the bulk case. We study two model systems of spherical silica (SI) and polystyrene (PS) nanoparticles, onto which PS chains are attached by grafting from process. These grafted nanoparticles are dispersed either in good solvent (THF) or in matrix (PS). By means of small angle x-ray scatering, the structure of bare and surface modified particles in solution is determined. We also use dynamic light scattering to estimate the hydrodynamic radii of bare, surface modified and PS grafted SI/PS particles in solution. Finally by contrast matching of core and solvent, small angle neutron scattering allows to investigate the conformation of PS chains grafted on the surface of SI and PS in solution or both PS grafted SI and PS in a PS matrix. This is achieved by varying grafting density and molecular weight of PS in solution, and by varying the molecular weight of PS matrix at constant grafted PS molecular weight in the matrix case.
In the latter situation, a decrease of the thickness of the grafted layer with increasing molecular weight of the matrix is found, contrary to PS grafted SI in PS matrix where no change is observed.