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Redox Controlled Partition and Spatial Distribution of Solvent and Salt in Electroactive Polyvinylferrocene Films†
journal contribution
posted on 2003-06-18, 00:00 authored by Andrew Glidle, Jon Cooper, A. Robert Hillman, Lee Bailey, Angela Jackson, John R. P. WebsterIn situ neutron reflectivity measurements have been made on spin cast polyvinylferrocene (PVF) films
maintained under electrochemical potential control. The data show that the interiors of both oxidized and
reduced films are close to homogeneous. The results show that neutron reflectivity measurements, including
isotopic substitution, can provide novel insights into film composition and structure at the electrode/polymer/solution interface. Isotopic substitution of the solvent has allowed the contributions of the solvent
and the solute to the total film composition to be separated. Responses were determined to variations in
the imposed potential (a constraint at the electrode/polymer interface) and the electrolyte concentration
(a constraint at the polymer/solution interface). Solvent entry occurs upon oxidation, resulting is a more
diffuse polymer/solution interface. Only at very high concentrations is salt permeation into PVF films
sufficiently high to be considered as a possible source of co-ions for redox-driven transfer in order to satisfy
electroneutrality.