INVESTIGADORES
TAGLIAZUCCHI Mario Eugenio
congresos y reuniones científicas
Título:
Electron, Ions and Solvent Exchange in Redox Polyelectrolytes Self-Assembled Multilayers
Autor/es:
TAGLIAZUCCHI, MARIO; WILLIAMS, FEDERICO J.; SZLEIFER, IGAL; CALVO, ERNESTO J.
Lugar:
Philadelphia
Reunión:
Conferencia; Amer. Chem. Soc., Division of Polymeric Materials: Science and Engineering; 2008
Institución organizadora:
American Chemical Society
Resumen:
We describe recent results with multilayers of poly(allyl-amine) modified covalently with Os(bpy)2PyCl+
(PAH-Os) and poly(vinyl sulfonate) by sequential adsorption
layer-by-layer. The intrinsic osmium redox PEMs were subject to cycles
of oxidation and reduction. A ?break in? first cycle effect was observed
due to the exchange of soluble ions in the electrolyte compensating
charge and the break of intrinsic polyion-polyion electrostatic bonds
with the formation of polyion-mobile ion bonds in the film. Upon
oxidation/ reduction intake of anions or release of cations into the
electrolyte has been detected with quartz crystal microbalance,
ellipsometry, probe beam deflection and cyclic voltammetry. FTIR
reflection-absorption spectroscopy confirmed the exchange of water
during redox switch of the films with simultaneous swelling. A molecular
theory that explicitly accounts for all the shape and size of all
species, the interactions and the acido base and redox equilibria
describes the complex system with strong local and non local coupling.