Search results for "Conductive polymer"

Reply to Comment on “Mixed Grotthuss and Vehicle Transport Mechanism in Proton Conducting Polymers from Ab initio Molecular Dynamics Simulations”

2011

A Highly Sensitive Hybrid Colorimetric and Fluorometric Molecular Probe for Cyanide Sensing Based on a Subphthalocyanine Dye

2006

A highly sensitive, selective colorimetric and fluorometric molecular probe based on a subphthalocyanine dye has been developed for cyanide-anion determination in aqueous solution. It has also been shown that a carboxysubphthalocyanine derivative can be covalently anchored to transparent mesoporous nanocrystalline high-surface-area metal oxide films to detect low concentrations of cyanide anion in pure water with no interference from other anionic or cationic species.

Evaluation of the electrochemical anion recognition ofNO3−-imprinted poly(Azure A) inNO3−/Cl−mixed solutions by ac-electrogravimetry

2016

Abstract During the reversible electrochemical reactions of the intrinsically conducting polymer (ICP) films, ions are inserted in them to balance the inner charge site of the polymer. For this reason, doped ICP films with anions or cations can be good candidates for the electrochemical removal of contaminant ions from wastewater. In this work, a polymer of a phenothiazine derivative (poly(Azure A or PAA)) was electrosynthesized by cyclic voltammetry in aqueous solutions using nitrate ions as a structural template. After that, PAA film was repeatedly cycled in identical conditions in a monomer-free solution. The electrochemical anion recognition of the nitrate-imprinted poly(Azure A) ( N O …

Behaviour of Nb2O5/PPy contacts: From Schottky barriers to p-n junctions

2009

In this work, a study of the photoelectrochemical responses of Nb O /PPy contacts fabricated in both organic 2 5 and aqueous solutions is performed. From the comparison between the experimental data of PPy photodeposited on Nb O in organic and in aqueous solutions, it is evident that the medium used for the photodeposition 2 5 influences the absorption coefficient, the band gap and flat band potential values.

Controlling the thermoelectric properties of polymers: application to PEDOT and polypyrrole

2015

Poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy) films have been prepared by an electrochemical method in a three electrode cell. The films have been obtained at different oxidation levels regarded as bipolaron, polaron and neutral states by varying the voltage, as is usually done in conjugated heterocyclic polymers. The voltage (-0.2V1.0 V) has been applied versus a Ag/AgCl reference electrode, producing a variation of one order of magnitude in the electrical conductivity and the Seebeck coefficient of the films. In the voltage range explored, the electrical conductivity increases from 80 to 766 S cm(-1) in PEDOT and from 15 to 160 S cm(-1) in PPy, while the Seebeck coefficie…

Charging process in electron conducting polymers: dimerization model

2001

Abstract Theory of the charging and discharging process in electron-conducting polymer films at an electrode surface has been presented. It is based on the concept of two coexisting subsystems at the polymer matrix, ‘usual’ sites P which can exchange with the electrode by the electronic charge in a quasi-reversible manner, and sites D where intermolecular bonds between neighboring polymer molecules can be formed. The charging and discharging of the latter subsystem may be realized along different reaction pathways, e.g. via the bond formation after the generation of two cation radicals within such site D in the course of the anodic scan while the bond dissociation may take place via a parti…

Electroanalytical chemistry for the analysis of solids: Characterization and classification (IUPAC Technical Report)

2012

Solid state electroanalytical chemistry (SSEAC) deals with studies of the processes, materials, and methods specifically aimed to obtain analytical information (quantitative elemental composition, phase composition, structure information, and reactivity) on solid materials by means of electrochemical methods. The electrochemical characterization of solids is not only crucial for electrochemical applications of materials (e.g., in batteries, fuel cells, corrosion protection, electrochemical machining, etc.) but it lends itself also for providing analytical information on the structure and chemical and mineralogical composition of solid materials of all kinds such as metals and alloys, variou…

A new BEDT-TTF salt and polypyrrole films containing the chiral polyoxometalate [H4Co2Mo10O38]6−

2005

Abstract The chiral polyoxometalate [H4Co2Mo10O38]6− has been used in the preparation of hybrid materials in the form of crystals or polymeric films. A new radical salt of the donor bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) containing the two enantiomers of this polyoxometalate has been obtained by electrocrystallization. This radical salt shows semiconducting behavior with room temperature conductivity of 9 S.cm−1 and activation energy of 40 meV. Polypyrrole films doped with a racemic mixture of polyoxometalates and also the enantiomerically pure (+)589-[H4Co2Mo10O38]6− have been prepared electrochemically. Circular dichroism experiments suggest that the chiral polyoxometalate…

EQCM and Quartz Crystal Impedance Measurements for the Characterization of Thiophene-Based Conducting Polymers

1999

AbstractEQCM was extensively used to investigate ion-transport phenomena during dopingundoping processes of electronically conducting polymers. Several early studies assumed that the polymer films were rigidly coupled to the quartz crystal so as to relate the mass change to the quartz crystal resonant frequency change via the Sauerbrey equation. However, the rigidity of electronically conducting polymer films is doubtful and it has to be demonstrated. Quartz crystal impedance analysis near the resonance is of paramount importance to get insight into the viscoelastic properties of the film [1] and to avoid misleading in the interpretation of EQCM data.This contribution presents and discusses…

A glassy carbon electrode modified by a triply-fused-like Co( ii ) polyporphine and its ability for sulphite oxidation and detection

2018

This article presents a Co(II) polyporphine conductive polymer easily and rapidly obtained (less than 2 h 30 min) on the surface of a glassy carbon electrode from the transformation of an initial Mg(II) porphine solution in a four-step process (including electrochemical and chemical stages). The intimate molecular structure is argued on the basis of the electrochemical response of the modified electrode, as well as its surface characterization. Owing to its apparent stability in water over potential cycling and its high density in active Co(II) centers, the electrosynthesized film shows its ability to catalyze sulphite oxidation in aqueous solutions. The mechanism of this molecular catalysi…