Preparation and spectroelectrochemical characterization of composite films of poly(3,4-ethylenedioxythiophene) with 4-(pyrrole-1-yl) benzoic acid (original) (raw)
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The Electrochemical Behaviour of PEDOT Film Electrosynthesized in Presence of Some Dopants
Open Journal of Organic Polymer Materials, 2015
Electropolymerization and characterization of poly(3,4-ethylene dioxythiophene) (PEDOT) doped with functionalized single-walled carbon nanotubes (SWANTs) polyaminobenzene sulfonic acid (PABS) and different dopants were studied. It was fabricated by a simple oxidative electropolymerization method. The nanocomposite coatings have been prepared by using electrochemical methods from aqueous solutions, such that the components were deposited onto platinum electrode substrate. The morphology of composite films was analyzed by scanning electron microscopy (SEM). The electrochemical and physical properties of the resulting composites were evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FT-IR) techniques in 0.1 M LiClO4 aqueous solutions. The value of specific electrochemical capacitance of the composite films is considerably higher than that of the pure polymers films. The improved properties of the electrodes were obtained by using these composite films. The dopant substances used were sodium dodecyl sulfate (SDS) and 1,2-Dihydroxy-benzene-3,5-disulfonic acid disodium salt hydrate (tiron).
Synthesis, electropolymerization and characterization of a cross-linked PEDOT derivative
Journal of Materials Chemistry, 2012
The synthesis of a novel electropolymerizable monomer, 2,2 0 ,3,3 0 -tetrahydro-2,2 0 -bithieno [3,4-b][1,4] dioxine (THBTD), based on two 3,4-ethylenedioxythiophene (EDOT) moieties connected through the ethylenedioxy bridge is reported. The new monomer paves the way for the development of cross-linked networks based on the EDOT moiety. Polymer films were electrogenerated from monomeric solutions by consecutive potential sweeps or by flow of constant anodic currents and the polymer structure was studied using FTIR. The relationship between the mass of the electrogenerated polymer (after reduction) and the polymerization charge gives the productivity of the consumed charge (mg C À1 ) while the charge stored and delivered by the films was determined by cyclic voltammetry getting the specific charge (C g À1 ). Simultaneously with the electroinitiated polymerization a chemical polymerization occurs around the electrode by monomer protonation giving protonated and no electroactive polymer chains. This chemical polymerization was followed in solution by UV-Vis spectroscopy using different conditions. Productivities and specific charges change with the conditions of synthesis in opposite directions. The voltammetric control presents a main redox couple (0.54/0.50 V) and a strong reduction process at À2.89 V that only can be reoxidized at more anodic potentials than 0.3 V as usual for charge trapping effects. EQCM studies indicate a remarkable difference between PEDOT and poly(THBTD). While poly(THBTD) shows a predominantly reversible anionic exchange during oxidation from the neutral state, the parent pristine PEDOT presents a mixed anionic and cationic exchange. Electrochromic color changes from an intense blue color of the oxidized film to a clear orange color in the reduced films as observed by in situ UV-Vis spectroscopy. Interestingly, the electrochromic changes in poly(THBTD) are opposed to those of PEDOT. Both thiophene derivative polymers present a similar thermal degradation at 305 and 314 C, respectively.
The Journal of Physical Chemistry B, 2010
The performance of different poly(3,4-ethylenedioxythiophene) (PEDOT) films was compared by electrochemical, spectroelectrochemical, and time-derivative measurements of absorbance versus potential (linear potentialscan voltabsorptometry) for an overall spectroelectrochemical characterization of the electrochromic properties in ionic liquids such as 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMITFSI). The timederivative signals were monitored at different wavelengths, and information obtained therefrom was complementary to that obtained from conventional cyclic voltammetry. PEDOT films prepared via in situ chemical oxidative polymerization appeared to be much more efficient than electropolymerized and PEDOT-poly(styrenesulfonate) (PSS) reference films, in terms of both contrast ratio and coloration efficiency, which was the case even for PEDOT films deposited on less conductive flexible plastic substrates.
Journal of Solid State Electrochemistry, 2008
Poly(3,4-ethylenedioxythiophene) (PEDOTh) films were deposited on platinum electrodes by consecutive potential scanning from acetonitrile solutions with 50 mM EDOTh. The effect of the supporting electrolyte used during electropolymerisation, namely LiClO 4 , TBAClO 4 and TBAPF 6 , in the redox behaviour, surface morphology and degree of crystallinity of the films has been investigated by cyclic voltammetry, X-ray diffraction analysis and scanning electron microscopy, respectively. The use of LiClO 4 leads to a higher electropolymerisation efficiency and an increase of electroactivity and crystallinity of the polymers. This electrolyte promotes the formation of a more compact morphology with clusters of different sizes. The film porosity increases when Li + is substituted by a larger cation, TBA +. The PEDOTh layer obtained with PF À 6 as counter ion is more porous than the obtained with CIO À 4 and presents a fibrillar aspect. The influence of the scan rate was also studied for films obtained in TBAClO 4 , and high electropolymerisation efficiency and an increase of crystallinity were observed for a low scan rate. PEDOTh films with different number of growing cycles were obtained in LiClO 4 , pointing their redox behaviour to structural rearrangement during thickening; the thicker film presents higher structural organization. It was possible to prepare films in different conditions, but with the same electroactivity, showing the same structural arrangement.
Morphology and conductivity of PEDOT layers produced by different electrochemical routes
Synthetic Metals, 2014
The electrochemical polymerization of 3,4-ethylenedioxythiophene (EDOT) in a polyanion, sodium poly(styrene-4-sulfonate)(NaPSS), has been performed through three different oxidative electropolymerizations on flexible electrodes. These electrodes have been fully characterized both at a macroscopic and microscopic scale. The morphology, characterized by Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) reveals a tendency of PEDOT:PSS to arrange in cauliflower-like shape. Homogeneity, grain dimension and electrical properties of the PEDOT layers can be tuned by choosing different polymerization routes and different parameters of electropolymerization. At the macroscopic level, we achieved a significant decrease of the impedance of the whole electrode after the electropolymerization thanks to an increase of both the intrinsic conductivity and the roughness of the electrode surface. Moreover Conductive Atomic Force Microscopy (C-AFM) study shows for the first time a clear relation between surface topography and local conductivity of the deposed film and help to clarify the conduction mechanism in electrodeposited PEDOT:PSS layers. The deposition was also shown to be very stable and resistant through thermal accelerated ageing tests that can mimic the behaviour of an implanted electrode after several months at human body temperature. The long term stability coupled with the low impedance make these electrodes suitable candidates for long-term neural probe applications.
International Journal of Polymer Science, 2016
Poly(3,4-ethylenedioxyhiophene) (PEDOT), polyaniline (PANI), and polypyrrole (PPy) were prepared on indium tin oxide (ITO) substrate via potentiostatic from aqueous solutions containing monomer and lithium perchlorate. The concentration of monomers was varied between 1 and 10 mM. The effects of monomer concentration on the polymers formation were investigated and compared by using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements. FTIR and Raman spectra showed no changes in the peaks upon the increment of the concentration. Based on the SEM images, the increment in monomer concentration gives significant effect on morphologies and eventually affects the electrochemical properties. PEDOT electrodeposited from 10 mM solution showed excellent electrochemical properties with the highest specific capacitance value of 12.8 mF/cm2.
Organic electrochemical transistors based on PEDOT with different anionic polyelectrolyte dopants
Journal of Polymer Science Part B, 2015
Recent applications of organic electrochemical transistors (OECTs) in bioelectronics motivate the search for new materials with mixed electronic and ionic conductivity. We investigate the characteristics of a series of poly(3,4-ethylenedioxythiophene) (PEDOT)-based materials with a new class of anionic polyelectrolytes used as dopants and stabilizers, replacing the traditionally used poly(styrene sulfonate) (PSS). We show that the backbone of the polyanion plays a major role in determining device performance, while its molecular weight and the counter ion used during PEDOT synthesis play a less important role. We find that transconductance increases with the degree of swelling of the film, consistent with enhanced ion transport. Finally, we identify a polymer that offers performance close to the state-of-the-art. This work highlights the importance of the polyanion phase as a means to control OECT performance. V
Electrochimica Acta, 2012
PEDOT layers were electrodeposited from aqueous solutions in the presence of various solubilizing agents. A systematic study involving a large number of solubilizers was conducted. The six surfactants used were sodium dodecyl sulfate (SDS) and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) (both anionic), Tween 80 and Triton X-100 (both non-ionic), hexadecyltrimethylammonium p-toluenesulfonate (HDTMA) and hexadecyl(2-hydroxyethyl)dimethylammonium dihydrogen phosphate (HDHEDMA) (both cationic). Two polyelectrolytes, sodium polystyrene sulfonate (PSS) and -carrageenan were also used.