Berlin 2005 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 9: SYMPOSIUM: Polymer networks and beyond: From molecular structure to materials and biological functions POSTER

CPP 9.9: Poster

Samstag, 5. März 2005, 16:45–18:45, Poster TU D

Preparation and Structure of Polystyrene Gels — •Ruigang Liu and Wilhelm Oppermann — Institute of Physical Chemistry, Technical University of Clausthal, Arnold-Sommerfeld Strasse 4, 38678 Clausthal-Zellerfeld, Germany

Static and dynamic light scattering measurements were performed on polystyrene gels prepared by crosslinking poly(styrene-co-aminomethylstyrene) with terephthalaldehyde in toluene. Static light scattering results show that the spatial inhomogeneities strongly decrease with increasing polymer concentration and grow stronger with cross-linker concentration. The analysis of the angular dependence of the excess scattering intensity by the Debye-Bueche method results in correlation lengths of some 10-50 nm. Relative mean-square concentration fluctuations on this length scale are about 8% for gels containing 5% PS and rise up to 75% when the PS concentration drops to 2%. Dynamic light scattering results show that the fluctuation component of the scattering intensity decreases with increasing polymer concentration while there is no obvious change with increasing crosslinker concentration. The cooperative diffusion coefficient Dc increases with increasing polymer concentration and crosslinker concentration.