Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 25: Polyelectrolytes
CPP 25.1: Vortrag
Mittwoch, 27. Februar 2008, 14:30–14:45, C 230
Effect of preparation parameters on the D2O/H2O uptake of polyelectrolyte multilayers — •Samuel Dodoo1, Roland Steitz2, and Regine von Klitzing1 — 1Stranski-Laboratorium für Physikalische & Theoretische Chemie, Institut für Chemie, TU Berlin, Strasse des 17. Juni 124, D-10623 Berlin — 2Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin
Polyelectrolyte multilayers (PEM) present a novel material of increasing interest. Their preparation via the layer-by-layer adsorption method1 offers a wide range of applications. We have investigated PEM of poly(styrene sulfonate) (PSS) and poly(diallyldimethyl ammoniumchloride) (PDADMAC) prepared at different NaCl concentrations, against water of different isotopes by neutron reflectometry2,3. The study addresses the effect of ionic strength and polymer charge on the water uptake by the multilayers. Increasing ionic strength increases thickness and swelling of the multilayers. The PEM swelled more in D2O than in H2O but this could not be attributed to replacement of H by D at the polymer. Two types of water were observed, "void water" about 10 vol-% which goes to fill the voids in the multilayers and "free water" about 40 vol-% which directly contributes to swelling of the multilayers. Measurements of effect of type of ions (Hoffmeister effect) are underway.
[1] Decher, G Science 1997, 277, 1232. [2] Steitz, R.; Leiner, V.; Siebrecht, R.; v. Klitzing, R. Colloids and Surfaces A 2000, 163, 63-70. [3] Steitz, R.; Leiner, V.; Tauer, K.; Khrenov, V.; v. Klitzing, R. Applied Physics A 2002, 74, S519-S521.