Regensburg 2007 – wissenschaftliches Programm
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SYPE: Symposium Polyelectrolytes
SYPE 2: Polyelectrolytes I
SYPE 2.3: Vortrag
Donnerstag, 29. März 2007, 14:45–15:00, H37
Adsorption of Light and Heavy Water Vapours in Polyelectrolyte Multilayer Films — Christophe Delajon1, •Thomas Gutberlet2, Helmuth Möhwald1, and Rumen Krastev1 — 1Max-Planck-Institute of Colloids and Interfaces, Wissenschaftspark Golm, 14424 Potsdam, Germany — 23Paul Scherrer Institute, 5232 Villigen, Switzerland
We studied the swelling and the uptake of water (H2O or D2O) vapours in polyelectrolyte (PE) multilayer (PEM) samples deposited on solid support (Si wafers) as a function of the isotope nature of the vapour and the charge of the last polymer layer. The samples were prepared with deuterated poly(sodium 4-styrenesulfonate) (dPSS) and poly(allylamine hydrochloride) (PAH). Two types of samples were studied. The sample with a structure Si/PEI/(dPSS/PAH)6/dPSS was negatively charged. A positively charged sample was PAH terminated and had the structure Si/PEI/(dPSS/PAH)6. The film thickness and density were estimated from neutron reflectometry experiments and the results were complemented with in-situ QCM measurements. The swelling of PEM in H2O and D2O vapours is the same, but the amount of sorbed water depends on the used water isotope. It is about twice as large in the case of D2O compared to H2O. We attribute the effect to the strength of the hydrogen and deuterium bonds formed between the water molecules and the PEM matrix. We also show that the amount of sorbed water depends on the nature of the last layer which builds the PEM.