Dresden 2006 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 5: Polyelectrolytes

CPP 5.3: Vortrag

Montag, 27. März 2006, 15:00–15:15, ZEU 160

Polyelectrolytes an polyelectrolytecomplexes in solution — •Ulrich Scheler and Ute Böhme — Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany

Electrostatic interaction determines the properties of polyelectrolytes in solution. Due to the electrostatic repulsion they adopt a more extended conformation than uncharged polymers in a good solvent. When the ionic strength of the solution is increased, polyelectrolytes adopt a more compact conformation which is reflected in an enhanced diffusion coefficient measured by PFG NMR. This effect becomes more prominent for couterions with higher valence. This effect has been studied on the example of poly(styrenesulfonate) of 77 kg/mol with a monovalent salt (NaCl) and a poly(diallyldimethylammonium chloride) PDADMAC of 5 kg/mol. Upon the addition of PDADMAC acting as a multivalent counterion, the diffusion coefficient is increased more drastically and a primary polyelectrolyte complex is formed. The effective charge of the complexes, measured by electrophoresis NMR, changes according to the composition of the complexes.