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1.
Poly(3,4-ethylenedioxythiophene) (PEDOT) films have been electropolymerized from an aqueous micellar solution comprising camphorsulfonic acid (CSA), lithium trifluoromethanesulfonate (LiCF3SO3) and EDOT. The inclusion of the dopants CS and CF3SO3 in the polymer structure and an unusually high doping level of 0.54 have been ascertained by the X-ray photoelectron spectroscopy. Transmission electron microscopy and atomic force microscopy studies show that the micellar effect of CSA leads to a morphology wherein polymer particles link together to form elongated shapes and also endows the film with a surface roughness of 25-30 nm. These nanostructures permit a facile intercalation-deintercalation of anions in the film during redox cycling. Electrochemical impedance spectroscopy show that the charge transfer phenomenon at the PEDOT-electrolyte interface is dominant in the high frequency region and diffusion controlled ionic movement prevails in the low frequency regime. The use of these films as potential cathodes in electrochromic windows is rationalized not only on the basis of their high scalability and ease of processing but also due to their large coloration efficiency (123 cm2 C−1) and transmission modulation (50%) at a photopic wavelength of 550 nm. But further improvement in color-bleach kinetics and reproducibility of redox behavior is desirable to broaden their spectrum of utility.  相似文献   

2.
Poly(3,4‐ethylenedioxythiophene) (PEDOT) nanoparticles were synthesized via chemical oxidation polymerization using 3,4‐ethylenedioxythiophene as the starting monomer and ammonium peroxydisulfate (APS) as the oxidant. The effects of APS concentration, surfactant concentration and type of surfactant, namely dodecylbenzenesulfonic acid and sodium dodecylsulfate, were investigated. Distinct particle shapes were obtained: irregular, raspberry agglomerate, coralliform, orange‐peel, globular and plum shapes. The particle sizes and the electrical conductivity are in the ranges 60 to 900 nm and <1 to 153 S cm?1, respectively, depending on the polymerization conditions. PEDOT synthesis in the absence of a surfactant yields a smaller particle size because a larger amount of initiator induces lower molecular weights and smaller PEDOT particles. The smaller PEDOT particles correspond to higher electrical conductivity because of the larger surface areas for electron transfer and a smaller amount of obstructing surfactant aliphatic segments. Moreover, particle size and shape can be varied, depending on surfactant type and concentration which dictate the micellar shapes in the polymerization reaction. This work is focused on the tailor‐made PEDOT shape and property relationship under synthesis conditions where several shapes have not been previously seen. © 2013 Society of Chemical Industry  相似文献   

3.
Immobilization of ascorbate oxidase (AO) in poly(3,4‐ethylenedioxythiophene) (PEDOT)/multiwalled carbon nanotubes (MWCNTs) composite films was achieved by one‐step electrochemical polymerization. The PEDOT/MWCNTs/AO modified electrode was fabricated by the entrapment of enzyme in conducting matrices during electrochemical polymerization. The PEDOT/MWCNTs modified electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The experimental results showed that the composite films exhibited better mechanical integrity, electrochemical activity, higher electronic and ionic conductivity, and larger redox capacitance compared with pure PEDOT films, which would be beneficial to the fabrication of PEDOT/MWCNTs/AO electrochemical biosensors. The scanning electron microscopy studies revealed that MWCNTs served as backbone for 3,4‐ethylenedioxythiophene (EDOT) electropolymerization. Furthermore, the resulting enzyme electrode could be used to determine L ‐ascorbic acid successfully, which demonstrated the good bioelectrochemical catalytic activity of the immobilized AO. The results indicated that the PEDOT/MWCNTs composite are a good candidate material for the immobilization of AO in the fabrication of enzyme‐based biosensor. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

4.
Poly(3,4‐ethylenedioxythiophene) (PEDOT) was in situ polymerized on nylon 6, poly(ethylene terephthalate) (PET), and poly(trimethylene terephthalate) (PTT) fabrics using ferric p‐toluenesulfonic acid (FepTS) and ferric chloride (FeCl3) as oxidants. The effect of the organic solvents used in the polymerization bath was investigated. Prepared PEDOT/nylon 6 composite fabrics have superior electrical conductivity (0.75 S/cm, in ethanol solvent) compared to those of the other PEDOT composite fabrics. In particular, after five cycles of polymerization, the electrical conductivity of the composite fabric reached about 2 S/cm. However, the nylon 6 fabric was damaged by EDOT radical cations and the strong acidity of FepTS during the polymerization process. It was concluded that PTT fabric, which has excellent elastic recovery and acid resistance, is a suitable substrate for in situ polymerization of PEDOT, because the PEDOT/PTT composite fabric was hardly damaged during the polymerization process and its electrical conductivity is comparatively good (0.36 S/cm, in butanol solvent). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1326–1332, 2005  相似文献   

5.
Poly(3,4-dialkoxythiophene) films with different length of alkyl chain (1,3 and 8 carbon atoms) were obtained on Pt and ITO electrodes from the monomer solutions in acetonitrile by cyclic voltammetry (CV). The properties of the resulting films were studied by electrochemical methods, UV-Vis, FTIR and NMR spectra. The CVs were correlated with differential cyclic voltabsorptograms (DCVA) recorded at the absorption maxima to explain the shape of the voltammograms of the polymers studied, dependent on the alkyl-chain length in alkoxy group. The presence of the zones of different crystallinity in the polymer film was postulated. Significant influence of the type of the solvent on asymmetry of the cyclic voltammograms for the polymer doping-undoping has been discussed in terms of the solvent interaction with radical cation (polaron) delocalized on the alkoxy side groups. The polaron delocalization was proved by 1H-NMR spectra. Appearance of infrared activated vibrations (IRAVs) in the range 1500-600 cm−1 and a characteristic electronic band at 3300 cm−1 at the polarization potential +0.25 V versus Ag/Ag+ and their gradual changes upon further polymer oxidation were interpreted in terms of evolution of different charge carriers in lightly and heavily doped polymer.  相似文献   

6.
Electrochemical response of regio-random and regio-controlled poly(3-hexylthiophene), P3HexTh, was investigated by cyclic voltammetry. P3HexTh underwent electrochemical oxidation at about 0.4 V vs. Ag+/Ag in a THF solution, and the peak anode electric current, ipa, was proportional to the sweeping rate v; ipa=const×v1/2. These data indicated that diffusion of the P3HexTh molecule in the solution was important to determine ipa. Application of a Matsuda's equation with assumptions gave a diffusion coefficient, D, of about 1×10−7 cm2 s−1 at molecular weight of about 5000, and the D value steeply decreased with increase in the molecular weight.  相似文献   

7.
Li Chen 《Electrochimica acta》2009,54(8):2335-2341
A noncovalent method was used to functionalize multiwalled carbon nanotubes with poly (sodium 4-styrene sulfonate). And then, the core-shell poly (3,4-ethylenedioxythiophene)/functionalized multiwalled carbon nanotubes (PEDOT/PSS-CNTs) nanocomposite was successfully realized via in situ polymerization under the hydrothermal condition. In the process, PSS served for not only solubilizing and dispersing CNTs well into an aqueous solution, but also tethering EDOT monomer onto the surface of CNTs to facilitate the formation of a uniform PEDOT coating. Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM) were used to characterize the resultant PEDOT/PSS-CNTs. In addition, the PEDOT/PSS-CNTs nanocomposite (50 wt.% PEDOT) had a specific capacitance (SC) of 198.2 F g−1 at a current density of 0.5 A g−1 and a capacitance degradation of 26.9% after 2000 cycles, much better than those of pristine PEDOT and PEDOT/CNTs (50 wt.% PEDOT). The enhanced electrochemical performance of the PEDOT/PSS-CNTs nanocomposite (50 wt.% PEDOT) should be attributed to the high uniform system of the nanocomposite, resulting in the large surface easily contacted by abundant electrolyte ions through the three-dimensional conducting matrix.  相似文献   

8.
The effects of alcoholic solvents on the charge transport properties of tosylate‐doped poly(3,4‐ethylenedioxythiophene) (PEDOT‐OTs) are investigated. The use of different alcoholic solvents in the oxidative chemical polymerization of 3,4‐ethylenedioxythiophene (EDOT) with iron(III)‐p‐tosylate led to a change in the electrical conductivity of PEDOT‐OTs. For example, PEDOT‐OTs prepared from methanol shows a conductivity of 20.1 S cm?1 which is enhanced by a factor of 200 as compared to PEDOT‐OTs prepared from hexanol. The variation of charge transport properties on the use of different alcoholic solvents is consistent with the data recorded by UV‐visible and electrospin resonance (ESR) measurements. From XPS experiments, the PEDOT‐OTs samples prepared from different alcoholic solvents were found to have almost the same doping level, suggesting that the number of charge carriers is not responsible for the change in conductivity. Supported by XRD results, it was found that the use of alcoholic solvents with shorter chain length induces more efficient packing of PEDOT chains. It is proposed that the alcoholic solvents associated with the counter ion of PEDOT via hydrogen bonding give rise to a change in the molecular ordering of PEDOT chains during the polymerization step, hence enhancing or depressing the inter‐chain hopping rate of the resulting PEDOT‐OTs. Copyright © 2005 Society of Chemical Industry  相似文献   

9.
The understanding of the redox behavior of conducting polymers is essential for a successful application of these so-called synthetic metals as functional coatings. The redox process involves the exchange of ions and solvent molecules. This so called doping/dedoping process involves changes of the mechanical and the electronic structure of the polymer. This paper discusses investigations at poly(3,4-ethylenedioxythiophene (PEDOT) and poly(pyrrole) (Ppy) by the electrochemical quartz crystal microbalance (EQCM) technique and electrochemical impedance spectroscopy (EIS). In the case of PEDOT a determination of the anion and the solvent fluxes was possible, and it was found that most anions replace solvent molecules upon their incorporation. The doping/dedoping mechanism of Ppy is more complicated. Here, the first redox cycles are characterized by a complex interplay of cation, anion and solvent fluxes with irreversible changes of the polymer structure. However, in combination with EIS new insights of the ion and solvent exchange and its influence on the electronic properties can be achieved.  相似文献   

10.
The electrochemical behaviors of poly(ferrocenylsilane) (PFS) films in organic solutions were investigated by means of cyclic voltammetry (CV) and electrochemical quartz crystals microbalance (EQCM). The influences of solvent on the electrochemical behavior of the films were discussed. In “good” solvents, the supporting electrolytes dissociated completely, the films were solvent-swollen moderately which provided a favorable condition for the electrolyte ions penetrating through, and the CV behavior of the films exhibited reversible or nearly reversible features. With increasing the carbon chain length of solvent molecule, however, the polarity of solvent reduced, which conduced to decrease the dissociation of electrolyte and the swelling of the polymer film. The efficiency of electrochemical reaction in the film was depressed, and the CV behavior of the film exhibited low reversibility. The solvent effects on the oxidation process of films exhibited more noticeable than the reduction process. The results supported the viewpoint that penetration of the electrolyte anions played an important role on the charge balance and transfer in the films during the CV process. The different electrochemical behaviors of the two PFS films in various organic solutions indicated that molecular structure of polymer had important influence on the electrochemical properties of the PFS.  相似文献   

11.
The initial stages of poly(3,4-ethylenedioxythiophene) (PEDOTh) film growth on platinum electrodes from TBAClO4/acetonitrile solution are investigated by means of current-time transient measurements and tapping mode atomic force microscopy. It is shown that, for growth potentials in the range 1.17-1.29 V vs. SCE, the deposition process involves the formation of oligomers in the solution, progressive nucleation of centres of the new phase and three-dimensional growth of a first compact layer followed by a non-uniform distribution of granular-like clusters, whose number and size increase with the synthesis potential and charge. The obtained results reveal that PEDOTh films prepared at distinct potentials but with the same growth charge (Qg) display similar electroactivities. They also depict that the electrochemical behaviour of the films is a function of the charge used for the synthesis, namely the reduction of tick PEDOTh layers (Qg > 20 mC cm−2) includes more that one step, as a consequence of the formation of a two-layered polymer film.  相似文献   

12.
Poly(5-cyano indole) or PCIND and poly(3,4-ethylenedioxy pyrrole) or PEDOP films have been electro-synthesized for the first time in a hydrophobic ionic liquid: trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate. PCIND, is an anodically coloring electrochrome, and exhibited a reversible switching between a transmissive yellow and a saturated green hue, with an absorption maximum at 650 nm in the fully oxidized state. Conducting atomic force microscopy studies revealed the PCIND film to be composed of an ensemble of segregated high current islands with a nanoscale electronic conductivity of 0.1 S cm−1 and a band gap of 1.41 eV. The cathodically coloring PEDOP film comprised of uniformly distributed and inter-connected high current carrying domains with a band gap of 1.82 eV and a conductivity of 5.4 S cm−1. Prototype electrochromic devices were fabricated using PEDOP and PCIND as cathode and anode with a thermally stable ionic liquid based, free standing polymeric gel film with a high ionic conductivity of 1.19 × 10−3 S cm−1 as the electrolyte. The device showed large coloration efficiencies of 480 and 796 cm2 C−1 at visible and NIR wavelengths of 475 and 1100 nm respectively which far exceeded the coloration efficiencies of the individual electrochromes, thereby demonstrating the synergy between the two colorants. The performance attributes of the device, which switched reversibly between red, green and blue hues, are an outcome of an interplay between the high nanolevel electron conduction capabilities (enable fast charge transport) and high ion storage capacities (increase optical contrast as more number of electrochemically addressable sites are accessed by the electrolyte ions) of the PEDOP and PCIND films. Our studies demonstrate the applicability of PCIND films as anodic electrochromes in energy efficient windows.  相似文献   

13.
Sulfonated thiophenes, sodium 2-(3-thienyloxy)ethanesulfonate (C6H7S2O4Na) and sodium 6-(3-thienyloxy)hexanesulfonate (C10H15S2O4Na), were synthesized and used in the fabrication of ion-selective electrodes (ISEs) sensitive and selective to Ag+. The Ag+-ISEs were prepared by galvanostatic electropolymerization of 3,4-ethylenedioxythiophene (EDOT) on glassy carbon (GC) electrodes, with either C6H7S2O4 or C10H15S2O4 as the charge compensator (doping ion) for p-doped poly(3,4-ethylenedioxythiophene) (PEDOT). Potentiometric measurements were carried out with these sensors, GC/PEDOT(C6H7S2O4) and GC/PEDOT(C10H15S2O4), to study and compare their sensitivity and selectivity to silver ions. PEDOT(C6H7S2O4) and PEDOT(C10H15S2O4) films were also studied by using other techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), electrochemical quartz crystal microbalance (EQCM) and Fourier transform infrared spectroscopy (FTIR).Results from the potentiometric measurements showed that the difference in length of the alkyl chain of the doping ions C6H7S2O4 and C10H15S2O4 has no significant effect on the sensitivity or selectivity of GC/PEDOT(C6H7S2O4) and GC/PEDOT(C10H15S2O4) sensors to Ag+. More differences can be seen in the cyclic voltammograms and EIS spectra of the sensors. FTIR spectra confirmed that both C6H7S2O4 and C10H15S2O4 act as doping ions in the electrosynthesis of PEDOT-based films and they are not irreversibly immobilized in the polymer backbone.  相似文献   

14.
The organic–inorganic material consisted of poly(3,4-ethylenedioxythiophene) (pEDOT) and copper hexacyanoferrate (Cuhcf) was synthesized. The pEDOT film with Fe(CN)63−/4− as counter-ions potentiodynamically polarized in aqueous CuCl2 electrolyte brings about stable hybrid material (pEDOT/Cuhcf) performing single redox activity of FeII/III at a formal potential Ef = 0.61 V (vs. Ag/AgCl/0.1 M KCl) and less clearly shaped two redox coming from copper ions entrapped inside the film. XPS ex situ measurements show three different binding energies for copper (Cu 2p3/2: 932.2, 934.8 and 936.3 eV) and two for iron (Fe 2p3/2: 708.2 and 709.0 eV). Spectroelectrochemical measurements allowed to establish an order in the energy band gap (Eg) for the investigated hybrids pEDOT/Mehcf (Me = Fe, Co, Ni, Cu) as follows: Eg(pEDOT/Fehcf) = 1.40 eV < Eg(pEDOT/Cohcf) = 1.48 eV < Eg(pEDOT/Nihcf) = 1.52 eV < Eg(pEDOT/Cuhcf) = 1.6 eV. The hybrid materials were examined as electrodes for electrocatalytic reduction of H2O2. Copper centres in pEDOT/Cuhcf as well as high spin iron centres in pEDOT/Fehcf were found to be electrocatalytically active towards hydrogen peroxide reduction.  相似文献   

15.
The ability of 4-(pyrrole-1-yl) benzoic acid (PyBA) to form monolayer-type carboxylate-derivatized ultra-thin organic films on solid electrode surfaces was explored here to attract coordinatively and immobilize Ni2+ ions at the electrode/electrolyte interface. In the next step, the system was exposed to Fe(CN)63− or Fe(CN)64− solution to form a robust nickel hexacyanoferrate (NiHCF) layer. By repeated and alternate treatments in solutions of PyBA, Ni2+ cations, and Fe(CN)63− or Fe(CN)64− anions, the amount of the material could be increased systematically in a controlled fashion to form three-dimensional multilayered NiHCF-based assemblies. The layer-by-layer method was also extended to the growth of hybrid conducting polymer stabilized NiHCF films in which the initial PyBA-anchored NiHCF layer (formed on glassy carbon) was subsequently exposed (a desired number of times) through alternate immersions to the monomer (3,4-ethylenedioxythiophene), Fe(CN)63− and Ni2+ solutions. During voltammetric potential cycling (electropolymerization) in the external supporting electrolyte solution, poly(3,4-ethylenedioxythiophene) or PEDOT linked NiHCF-based multilayered films were produced. They were characterized by good stability and high dynamics of charge transport.  相似文献   

16.
Bilayers of drop casted C60 fullerene films and electrochemically synthesized poly(3,4-ethylenedioxythiophene) (PEDOT) films have been studied. The PEDOT film was polymerised by cyclic voltammetry on top of the drop casted C60 fullerene film. The bilayer films were produced and characterized in three different electrolytes; tetrabutylammoniumhexafluorophosphate (TBAPF6) and lithium hexafluorophosphate (LiPF6) in acetonitrile (ACN) and in the ionic liquid 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMIMBF4). The bilayers were studied by cyclic voltammetry and in situ Fourier transform infrared attenuated total reflection (FTIR-ATR) spectroscopy. Both p- and n-doping of the bilayer films were studied and compared with PEDOT films prepared in organic media.  相似文献   

17.
Electrochemical properties of poly(3,4-ethylenedioxythiophene) doped with hexacyanoferrate(II,III) ions (PEDOT(HCF)) were studied in the presence of Cu2+ ions. Voltammetric and EDAX studies revealed retention of hexacyanoferrate anions in the polymer film and accumulation of Cu(II) cations, as well as formation of solid copper hexacyanoferrate near the polymer surface.Accumulation of Cu2+ ions was found to be advantageous from the point of view of PEDOT(HCF) applications as a solid contact (ion-to-electron transducer) in all-solid-state Cu2+-selective electrodes with solvent polymeric polyvinyl chloride (PVC) based membrane, containing Cu2+-selective ionophore. Binding of Cu2+ ions in the conducting polymer layer results in analyte ions flux into the transducer phase. Thus, pronounced enhancement of selectivity of the all-solid-state Cu2+-selective electrode or lower detection limit of the potentiometric response range was achieved, reaching under optimised conditions 10−7 M CuSO4.  相似文献   

18.
CdS-poly(3,4-dioctyloxythiophene) (CdS-PDOT) hybrid electrode has been prepared by electrosynthesis of PDOT on Au substrate followed by electrodeposition of Cd and its chemical transformation into CdS. The polymer and semiconductor obtained by this method form hemispherical structures dispersed on the substrate. The synthesized composites were characterized by UV-vis absorption spectra and energy dispersive X-ray spectra (EDS). The AFM images of the electrodes covered with different amounts of each component were correlated with photoactivity of the hybrid electrodes. Photoresponses of Au/PDOT-CdS electrodes under illumination in aqueous solution of Na2S were also compared with those of CdS without polymer. Enhancement of the photocurrent achieved for some polymer-to-semiconductor ratio is discussed in terms of the hybrid electrode morphology and hole-mediating properties of PDOT. The power conversion efficiency of the device based on CdS-PDOT hybrid electrode was determined from photocurrent-potential behavior of two electrode system, Au/CdS-PDOT/0.1 M Na2S/Pt with a variable resistance in series in the external circuit.  相似文献   

19.
导电聚合物PEDOT/PSS-MPEG的制备及性能   总被引:1,自引:1,他引:0       下载免费PDF全文
刘书英  李坚  李玉玲 《化工学报》2012,63(4):1321-1327
引言导电高分子既有导体材料的光电学特性,又有良好的力学性能和可加工性[1],这使得导电高分子材料具有广泛的应用前景。聚噻吩类有机导电材料[2]就是这类材料中的一种。聚噻吩的室温电导率  相似文献   

20.
Synthesis of a titanocene dichloride derivative functionalized with 3,4-etylenedioxythiophene group, Tc1EDOT (Cl2TiCpC5H4(CH2) (3,4-ethylenedioxythiophene)) has been described. Redox behavior of the monomer in tetrahydrofuran (THF), dichloromethane (DCM) and acetonitrile (AN) at different scan rates has been discussed in terms of different ability of these solvents to coordination with the reduced titanocene (Tc) complex and the solvation of Cl anions. Electrooxidation of Tc1EDOT to get a conducting polymer film with immobilized titanocene dichloride centers and electrochemical properties of its polymer matrix in background acetonitrile solution have been compared with those of non-substituted PEDOT and PEDOT-methanol derivative (PEDOTMet), to elucidate the effect of substituents both on polymerization and redox potentials of the matrix. STM and AFM images of p(Tc1EDOT) films obtained with potentiodynamic and potentiostatic regimes are compared to illustrate that the films deposited at constant potential are better ordered and more compact than those obtained by cyclic voltammetry. A comparison of the cyclic voltammograms of p(Tc1EDOT) and poly(titanocene-propyl-pyrrole) (p(Tc3Py)) films in 0.1 TBAPF6 in THF has shown that the electroactivity of the polymer matrix of p(Tc1EDOT) is extended to more negative potentials in comparison to that of p(Tc3Py). This results in the anodic shift of redox potential of Tc centers immobilized in p(Tc1EDOT) film with respect to that of the centers fixed in p(Tc3Py).  相似文献   

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