Dresden 2009 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 18: Polyelectrolytes
CPP 18.11: Vortrag
Dienstag, 24. März 2009, 12:15–12:30, ZEU 114
Immobile Light Water and Proton-Deuterium Exchange in Polyelectrolyte Multilayers — •Oxana Ivanova1, Olaf Soltwedel1, Roland Steitz2, Ralf Köhler2, and Christiane A. Helm1 — 1Institut für Physik, Uni Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald — 2Leibnitz-Zentrum für Material- und Energieforschung Berlinm
To describe the swelling of polyelectrolyte multilayers (PEMs) on a molecular scale, the PEM architecture is varied. The polyanion is poly(styrenesulfonate) (PSS) and the polycation poly(allylamine hydrochloride) (PAH). PEM either consists of 10 protonated polyelectrolyte bilayers (p_10), 10 deuterated bilayers (d_10), or two different blocks, p_5d_5 or d_5p_5. Prior to the exposure to 100 % relative humidity (RH) D2O or H2O, the PEM is immersed in liquid D2O or H2O, respectively. The obtained scattering length density profiles provide insight into the exchange rates of the constituent molecules: The data indicate that three mobile protons of each PAH monomer are replaced by deuterium ions, yet most of the H2O molecules found in PEM at 0% RH remain bound at 100% RH D2O. This is in consistency with the fact that the core of PEM is in a glassy state. At 0% RH, the amount of bound water in the deuterated layers does not depend on the film architecture, whereas in the protonated layers it does.