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Polyaniline , SECM studies

M.H.T. Frank and G. Denuault, Scanning electrochemical microscope (SECM) study of the relationship between proton concentration and electronic charge as a fimction of ionic-strength during the oxidation of polyaniline. J. Electroanal. Chem., 379, 399 (1994). [Pg.159]

Liljeroth et al. [80] used SECM in the feedback mode to study the electronic conductivity of a film of gold nanoparticles deposited at various pressures on a nonconductive substrate. They were able to observe an insulator-to-metal transition associated with a change in surface pressure. Unwin Whitworth et al. [83] have also developed a method to determine the electronic conductivity of ultrathin films using SECM under steady-state conditions. They obtained analytical approximations for the fitting of approach curves. The usefulness of their approach was demonstrated by investigating the effect of surface pressure on conductivity of a polyaniline monolayer at the water-air interface. [Pg.225]

Lateral charge propagation in a monolayer of polyaniline has been monitored with an SECM [129] kinetic data could be extracted by modeling. The charge transfer between a dissolved redox mediator and polyalkylterthiophene films has been studied [130]. In the oxidized (/ -doped) state of the film, redox reactions proceeded at the film/solution interface, not inside the film. In the reduced state the film behaved like a completely passivating film and penetration of redox mediator ions into the film was obviously completely inhibited. [Pg.267]

Deposition of condncting polymers can be accomplished by either direct or feedback modes of SECM. In an earlier study, SECM was used to deposit polyaniline on a Pt substrate by scanning a UME tip in thin, ionically conductive Nafion films coated on the Pt surface (127). Anilinium ions were incorporated into Nafion films and the Pt substrate was biased positively, which caused the electropolymerization of aniline. The resolution of the polyaniline deposition is controlled by the tip size, the thickness of Nafion films, and the electric field distribution. [Pg.522]

A general approach to fabricating solid-state ion-selective microelectrodes has been described whereby a conducting electroactive polymer, which is both an electronic and an ionic conductor (e.g., polypyrrole, polythiophene, or polyaniline), is used to mediate charge exchange between an ion-selective membrane (an ion conductor) and a metal substrate (an electronic conductor) [28]. These electrodes are reported to be robust and mechanically flexible while exhibiting good potential stability with no redox sensitivity. While applications to potentiometric SECM have been described [28], these electrodes have yet to find use in corrosion studies. [Pg.458]


See other pages where Polyaniline , SECM studies is mentioned: [Pg.123]    [Pg.230]    [Pg.315]    [Pg.230]    [Pg.208]    [Pg.234]    [Pg.644]    [Pg.173]   
See also in sourсe #XX -- [ Pg.230 ]




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