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Conducting Polymers (conducting + polymer)
Terms modified by Conducting Polymers Selected AbstractsPreparation, Characterization and Analytical Applications of a New and Novel Electrically Conducting PolymerELECTROANALYSIS, Issue 15 2006F. D'Eramo Abstract In this study, a glassy carbon electrode (GC) was modified with an electropolymerized film of 1-naphthylamine (1-NAP) with a subsequent overoxidation treatment in 0.2,M sodium hydroxide solution. This polymer p-1-NAPox film coated GC electrode was used for the selective determination of dopamine (DA) in the presence of a triple concentration of ascorbic acid (AA). These studies were performed using cyclic voltammetry and square-wave voltammetry at physiological pH. p-1-NAPox shows an attractive permselectivity, a marked enhancement of the current response and antifouling properties when compared to a bare GC electrode activated in basic media. With a preconcentration time of 3,minutes at open circuit, linear calibration plots were obtained for DA in buffer solution (pH,7.4) over the concentration range from 1×10,6,1×10,4 M with a detection limit of 1.59×10,7 M. [source] Conducting Polymer-Based Solid-State Ion-Selective ElectrodesELECTROANALYSIS, Issue 1 2006Johan Bobacka Abstract Conducting polymers, i.e., electroactive conjugated polymers, are useful both as ion-to-electron transducers and as sensing membranes in solid-state ion-selective electrodes. Recent achievements over the last few years have resulted in significant improvements of the analytical performance of solid-contact ion-selective electrodes (solid-contact ISEs) based on conducting polymers as ion-to-electron transducer combined with polymeric ion-selective membranes. A significant amount of research has also been devoted to solid-state ISEs based on conducting polymers as the sensing membrane. This review gives a brief summary of the progress in the area in recent years. [source] Selective Electrochemical Analysis of Various Metal Ions at an EDTA Bonded Conducting Polymer Modified ElectrodeELECTROANALYSIS, Issue 16 2004Aminur Rahman Abstract An EDTA-bonded conducting polymer modified electrode was prepared and characterized by FT-IR. The modified electrode was used for the selective electrochemical analysis of various trace metal ions such as, Cu(II), Hg(II), Pb(II), Co(II), Ni(II), Fe(II), Cd(II), and Zn(II) at the different pHs by linear sweep and square wave voltammetry. Dynamic ranges were obtained using square wave voltammetry from 0.1,,M to 10.0,,M for Co(II), Ni(II), Cd(II), Fe(II), and Zn(II) and 0.5,nM to 20,nM for Cu(II), Hg(II), and Pb(II) after 10,min of preconcentration. The detection limits were determined to be 0.1,nM, 0.3,nM, 0.4,nM, 50.0,nM, 60.0,nM, 65.0,nM, 80.0,nM, and 90.0,nM for Cu(II), Hg(II), Pb(II), Co(II), Ni(II), Cd(II), Fe(II), and Zn(II), respectively. The technique offers an excellent way for the selective trace determination of various heavy metal ions in a solution. [source] Potentiometric Ag+ Sensors Based on Conducting Polymers: A Comparison between Poly(3,4-ethylenedioxythiophene) and Polypyrrole Doped with Sulfonated CalixarenesELECTROANALYSIS, Issue 18 2005Zekra Mousavi Abstract Potentiometric Ag+ sensors were prepared by galvanostatic electropolymerization of 3,4-ethylenedioxythiophene (EDOT) and pyrrole (Py) on glassy carbon electrodes by using sulfonated calixarenes as doping ions. Poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy) doped with p -sulfonic calix[4]arene (C4S), p -sulfonic calix[6]arene (C6S) and p -sulfonic calix[8]arene (C8S) were compared. PEDOT and PPy doped with poly(styrene sulfonate) (PSS) were also included for comparison. The analytical performance of the conducting polymer-based Ag+ sensors was studied by potentiometric measurements. All conducting polymer and dopant combinations showed sensitivity and selectivity to Ag+ compared to several alkali, alkaline-earth, and transition-metal cations. The type of the conducting polymer used for the fabrication of the electrodes was found to have a more significant effect on the selectivity of the electrodes to Ag+ than the ring size of the sulfonated calixarenes used as dopants. Selected conducting polymer-based sensors were studied by cyclic voltammetry (CV) and energy dispersive analysis of X-rays (EDAX) measurements. Results from the EDAX measurements show that both PEDOT- and PPy-based membranes accumulate silver. [source] Biosensors Based on Aligned Carbon Nanotubes Coated with Inherently Conducting PolymersELECTROANALYSIS, Issue 13 2003Mei Gao Abstract The use of multiwalled aligned carbon nanotubes provides a novel electrode platform for inherently conducting polymer based biosensors. The example used here to highlight the usefulness of such a platform is the polypyrrole based glucose oxidase system for detection of glucose. The use of these three dimensional electrodes offers advantages in that large accessible enzyme loadings can be obtained within an ultrathin layer. It has also been found that the detection of H2O2 at these new electrode structures containing iron loaded nanotube tips can be achieved at low anodic potentials. The result is a sensitive and selective glucose sensor. [source] Conducting Polymers: An Optically Active Polythiophene Exhibiting Electrochemically Driven Light-Interference Modulation (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 9 2009Mater. This frontispiece shows a polarizing optical microscopy image of optically active polythiophene (PT) prepared in cholesteric liquid-crystal electrolyte solution containing a cholesterol derivative. The PT film exhibits a variable diffraction function, electrochemically driven refractive index modulation, and electrochromism originating from the periodic dielectric structure, representing a form of structural electrochromism, as described on page 1335. [source] Formation of Chiral Mesopores in Conducting Polymers by Chiral-Lipid-Ribbon Templating and "Seeding" Route,ADVANCED FUNCTIONAL MATERIALS, Issue 18 2008Chaxing Fan Abstract Conducting polymer nanofibers with controllable chiral mesopores in the size, the shape, and handedness have been synthesized by chiral lipid ribbon templating and "seeding" route. Chiral mesoporous conducting poly(pyrrole) (CMPP) synthesized with very small amount of chiral amphiphilic molecules (usually,<,3%) has helically twisted channels with well-defined controllable pore size of 5,20,nm in central axis of the twisted fibers. The structure and chirality of helical mesopores have been characterized by high-resolution transmission electron microscope (HRTEM), scanning electron microscope (SEM) and electron tomography. The average pore diameters of chiral mesopores were approximately estimated from the N2 adsorption,desorption data and calculated by the conversion calculation from helical ribbons to a rectangular straight tape. The pore size of CMPP has been controlled by choosing different alkyl chain lengths of chiral lipid molecules or precisely adjusting the H2O/EtOH volume ratio. [source] Spatially Selective Functionalization of Conducting Polymers by "Electroclick" ChemistryADVANCED MATERIALS, Issue 44 2009Thomas Steen Hansen Conducting polymer microelectrodes can electrochemically generate the catalyst required for their own functionalization by "click chemistry" with high spatial resolution. Interdigitated microelectrodes prepared from an azide-containing conducting polymer are selectively functionalized in sequence by two alkyne-modified fluorophores by control of the applied potentials. [source] Solid-State Conversion of Processable 3,4-Ethylenedioxythiophene (EDOT) Containing Poly(arylsilane) Precursors to , -Conjugated Conducting Polymers,ADVANCED MATERIALS, Issue 6 2008Jayesh G. Bokria The thermal degradation products of poly(methyl meth acrylate) model compounds in an ambient atmosphere were mapped via high-resolution electrospray ionization quadrupole ion trap time of flight (Q-ToF) mass spectro metry. [source] Facile Synthesis of Spherical Polyelectrolyte Brushes as Carriers for Conducting Polymers to be Used in Plastic ElectronicsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 18 2009Jianjun Wang Abstract A two-step method for the preparation of spherical polyelectrolyte brushes (SPBs) has been developed. Copolymerization of styrene and divinyl benzene at the particle surface resulted in a large number of accessible vinyl groups. These vinyl groups reacted with sodium styrene sulfonate to give SPBs. The SPBs were used as carriers for conducting polymers resulting in redispersible conducting inks with good film forming properties. Direct current (DC) conductivity of the polypyrrole (PPy) loaded samples showed a percolating behavior as probed by impedance spectroscopy. Finally, device performance of organic light-emitting diodes based on the conducting thin films assembled from the PPy loaded particles was tested. [source] 3,4-Alkylenedioxy Ring Formation via Double Mitsunobu Reactions: An Efficient Route for the Synthesis of 3,4-Ethylenedioxythiophene (EDOT) and 3,4-Propylenedioxythiophene (ProDOT) Derivatives as Monomers for Electron-Rich Conducting Polymers.CHEMINFORM, Issue 11 2003Kyukwan Zong No abstract is available for this article. [source] Conducting Polymer-Based Solid-State Ion-Selective ElectrodesELECTROANALYSIS, Issue 1 2006Johan Bobacka Abstract Conducting polymers, i.e., electroactive conjugated polymers, are useful both as ion-to-electron transducers and as sensing membranes in solid-state ion-selective electrodes. Recent achievements over the last few years have resulted in significant improvements of the analytical performance of solid-contact ion-selective electrodes (solid-contact ISEs) based on conducting polymers as ion-to-electron transducer combined with polymeric ion-selective membranes. A significant amount of research has also been devoted to solid-state ISEs based on conducting polymers as the sensing membrane. This review gives a brief summary of the progress in the area in recent years. [source] Electro-synthesized PEDOT/glutamate chemically modified electrode: a combination of electrical and biocompatible featuresPOLYMER INTERNATIONAL, Issue 5 2008Jianfei Che Abstract BACKGROUND: Neural prosthetic devices have been developed that can facilitate the stimulation and recording of electrical activity when implanted in the central nervous system. The key parts of the devices are metal (gold) electrodes; however, surface modification of the gold electrode is desired. Conducting polymers are promising candidates for this purpose. RESULTS: A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was electro-polymerized onto gold electrodes with a neural transmitter of glutamate (Glu) as dopant. A protocol of ion exchange was employed due to the difficulty of direct incorporation of Glu into PEDOT. Sodium p -toluenesulfonate (TSNa) was chosen as the first dopant and subsequent incorporation of Glu was accomplished via ion exchange. The electrochemical properties of the resultant PEDOT/Glu were studied using electrochemical impedance spectroscopy and cyclic voltammetry. The purpose of incorporating Glu was to improve the biocompatibility of the coated electrode. The PEDOT/Glu-coated electrode showed better cell attachment compared with a PEDOT/TSNa-coated electrode in in vitro cell culture of PC12. The stability of PEDOT was studied by immersing the coated electrode in a biologically relevant reducing agent of glutathione. CONCLUSION: The charge capacity of the coated electrode had an initial slight decrease and then remained unchanged. Good electro-activity was conserved, indicating the superior stability of PEDOT in the biological environment. Copyright © 2007 Society of Chemical Industry [source] Xanthine Sensors Based on Anodic and Cathodic Detection of Enzymatically Generated Hydrogen PeroxideELECTROANALYSIS, Issue 6 2007Aminur Rahman Abstract A xanthine biosensor was fabricated by the covalent immobilization of xanthine oxidase (XO) onto a functionalized conducting polymer (Poly-5, 2,: 5,, 2,-terthiophine-3-carboxylic acid), poly-TTCA through the formation of amide bond between carboxylic acid groups of poly-TTCA and amine groups of enzyme. The immobilization of XO onto the conducting polymer (XO/poly-TTCA) was characterized using cyclic voltammetry, quartz crystal microbalance (QCM), and X-ray photoelectron spectroscopy (XPS) techniques. The direct electron transfer of the immobilized XO at poly-TTCA was found to be quasireversible and the electron transfer rate constant was determined to be 0.73,s,1. The biosensor efficiently detected xanthine through oxidation at +0.35,V and reduction at ,0.25,V (versus Ag/AgCl) of enzymatically generated hydrogen peroxide. Various experimental parameters, such as pH, temperature, and applied potential were optimized. The linear dynamic ranges of anodic and cathodic detections of xanthine were between 5.0×10,6,1.0×10,4 M and 5.0×10,7 to 1.0×10,4,M, respectively. The detection limits were determined to be of 1.0×10,6,M and 9.0×10,8,M with anodic and cathodic processes, respectively. The applicability of the biosensor was tested by detecting xanthine in blood serum and urine real samples. [source] Potentiometric Ag+ Sensors Based on Conducting Polymers: A Comparison between Poly(3,4-ethylenedioxythiophene) and Polypyrrole Doped with Sulfonated CalixarenesELECTROANALYSIS, Issue 18 2005Zekra Mousavi Abstract Potentiometric Ag+ sensors were prepared by galvanostatic electropolymerization of 3,4-ethylenedioxythiophene (EDOT) and pyrrole (Py) on glassy carbon electrodes by using sulfonated calixarenes as doping ions. Poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy) doped with p -sulfonic calix[4]arene (C4S), p -sulfonic calix[6]arene (C6S) and p -sulfonic calix[8]arene (C8S) were compared. PEDOT and PPy doped with poly(styrene sulfonate) (PSS) were also included for comparison. The analytical performance of the conducting polymer-based Ag+ sensors was studied by potentiometric measurements. All conducting polymer and dopant combinations showed sensitivity and selectivity to Ag+ compared to several alkali, alkaline-earth, and transition-metal cations. The type of the conducting polymer used for the fabrication of the electrodes was found to have a more significant effect on the selectivity of the electrodes to Ag+ than the ring size of the sulfonated calixarenes used as dopants. Selected conducting polymer-based sensors were studied by cyclic voltammetry (CV) and energy dispersive analysis of X-rays (EDAX) measurements. Results from the EDAX measurements show that both PEDOT- and PPy-based membranes accumulate silver. [source] Selective Electrochemical Analysis of Various Metal Ions at an EDTA Bonded Conducting Polymer Modified ElectrodeELECTROANALYSIS, Issue 16 2004Aminur Rahman Abstract An EDTA-bonded conducting polymer modified electrode was prepared and characterized by FT-IR. The modified electrode was used for the selective electrochemical analysis of various trace metal ions such as, Cu(II), Hg(II), Pb(II), Co(II), Ni(II), Fe(II), Cd(II), and Zn(II) at the different pHs by linear sweep and square wave voltammetry. Dynamic ranges were obtained using square wave voltammetry from 0.1,,M to 10.0,,M for Co(II), Ni(II), Cd(II), Fe(II), and Zn(II) and 0.5,nM to 20,nM for Cu(II), Hg(II), and Pb(II) after 10,min of preconcentration. The detection limits were determined to be 0.1,nM, 0.3,nM, 0.4,nM, 50.0,nM, 60.0,nM, 65.0,nM, 80.0,nM, and 90.0,nM for Cu(II), Hg(II), Pb(II), Co(II), Ni(II), Cd(II), Fe(II), and Zn(II), respectively. The technique offers an excellent way for the selective trace determination of various heavy metal ions in a solution. [source] Biosensors Based on Aligned Carbon Nanotubes Coated with Inherently Conducting PolymersELECTROANALYSIS, Issue 13 2003Mei Gao Abstract The use of multiwalled aligned carbon nanotubes provides a novel electrode platform for inherently conducting polymer based biosensors. The example used here to highlight the usefulness of such a platform is the polypyrrole based glucose oxidase system for detection of glucose. The use of these three dimensional electrodes offers advantages in that large accessible enzyme loadings can be obtained within an ultrathin layer. It has also been found that the detection of H2O2 at these new electrode structures containing iron loaded nanotube tips can be achieved at low anodic potentials. The result is a sensitive and selective glucose sensor. [source] Spatially Selective Functionalization of Conducting Polymers by "Electroclick" ChemistryADVANCED MATERIALS, Issue 44 2009Thomas Steen Hansen Conducting polymer microelectrodes can electrochemically generate the catalyst required for their own functionalization by "click chemistry" with high spatial resolution. Interdigitated microelectrodes prepared from an azide-containing conducting polymer are selectively functionalized in sequence by two alkyne-modified fluorophores by control of the applied potentials. [source] Titania/Polypyrrole Hybrid Nanocomposites Built from In-Situ Generated Organically Functionalized Nanoanatase Building Blocks,ADVANCED MATERIALS, Issue 3 2003S. Roux A bifunctional capping ligand is used to obtain pyrrol-functionalized monodispersed nanocrystalline TiO2 (anatase) particles in a single step. The pyrrole functionalities in the shell are then (electro)chemically polymerized to create a polypyrrole (PPy)/TiO2 hybrid nanocomposite film (see Figure). Further electronic modification of the conducting polymer is possible, leading to a great variety of potential applications. [source] Incorporation of deMon2k as a new parallel quantum mechanical code for the PUPIL systemJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 14 2010Oscar Bertran Abstract The PUPIL system is a combination of software and protocols for the systematic linkage and interoperation of molecular dynamics and quantum mechanics codes to perform QM/MD (sometimes called QM/MM) calculations. The Gaussian03 and Amber packages were added to the PUPIL suite recently. However, efficient parallel QM codes are critical because calculation of the QM forces is the overwhelming majority of the computational load. Here we report details of incorporation of the deMon2k density functional suite as a new parallel QM code. An additional motivation is to add a highly optimized, purely DFT code. We illustrate with a demonstration study of the influence of perchlorate as a dopant ion of the poly(3,4-ethylenedioxythiophene) conducting polymer in explicit acetonitrile solvent using Amber and deMon2k. We discuss unanticipated requirements for use of a scheme for semi-empirical correction of Kohn-Sham eigenvalues to give physically meaningful one-electron gap energies. We provide comparison of both geometric parameters and electronic properties for nondoped and doped systems. We also present results comparing deMon2k and Gaussian03 calculation of forces for a short sequence of steps. We discuss briefly some difficult problems of quantum zone SCF convergence for the anionically doped system. The difficulties seem to be caused by well-know deficiencies in simple approximate exchange-correlation functionals. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 [source] Conducting Polymer Enzyme Alloys: Electromaterials Exhibiting Direct Electron TransferMACROMOLECULAR RAPID COMMUNICATIONS, Issue 14 2010Brianna C. Thompson Abstract Glucose oxidase (GOx) is an important enzyme with great potential application for enzymatic sensing of glucose, in implantable biofuel cells for powering of medical devices in vivo and for large-scale biofuel cells for distributed energy generation. For these applications, immobilisation of GOx and direct transfer of electrons from the enzyme to an electrode material is required. This paper describes synthesis of conducting polymer (CP) structures in which GOx has been entrained such that direct electron transfer is possible between GOx and the CP. CP/enzyme composites prepared by other means show no evidence of such "wiring". These materials therefore show promise for mediator-less electronic connection of GOx into easily produced electrodes for biosensing or biofuel cell applications. [source] Extent of thermal ablation suffered by model organic microparticles during aerogel capture at hypervelocitiesMETEORITICS & PLANETARY SCIENCE, Issue 10 2009M. J. Burchell Commercial polystyrene particles (20 ,m diameter) were coated with an ultrathin 20 nm overlayer of an organic conducting polymer, polypyrrole. This overlayer comprises only 0.8% by mass of the projectile but has a very strong Raman signature, hence its survival or destruction is a sensitive measure of the extent of chemical degradation suffered. After aerogel capture, microparticles were located via optical microscopy and their composition was analyzed in situ using Raman microscopy. The ultrathin polypyrrole overlayer survived essentially intact for impacts at ,1 km s,1, but significant surface carbonization was found at 2 km s,1, and major particle mass loss at ,3 km s,1. Particles impacting at ,6.1 km s,1 (the speed at which cometary dust was collected in the NASA Stardust mission) were reduced to approximately half their original diameter during aerogel capture (i.e., a mass loss of 84%). Thus significant thermal ablation occurs at speeds above a few km s,1. This suggests that during the Stardust mission the thermal history of the terminal dust grains during capture in aerogel may be sufficient to cause significant processing or loss of organic materials. Further, while Raman D and G bands of carbon can be obtained from captured grains, they may well reflect the thermal processing during capture rather than the pre-impact particle's thermal history. [source] Detection of volatile organic compounds using a polythiophene derivativePHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2010V. C. Gonçalves Abstract Conjugated polymers have been subject of great interest in the recent literature from both fundamental point of view and applied science perspective. Among the several types of conjugated polymers used in recent investigations, polythiophene and its derivatives have attracted considerable attention over the past 20,years due to their high mobility and other remarkable solid-state properties. They have potential applications in many fields, such as microelectronic devices, catalysts, organic field-effect transistors, chemical sensors, and biosensors. They have been studied as gas and volatile organic compounds (VOCs) sensors using different principles or transduction techniques, such as optical absorption, conductivity, and capacitance measurements. In this work, we report on the fabrication of gas sensors based on a conducting polymer on an interdigitated gold electrode. We use as active layer of the sensor a polythiophene derivative: poly (3-hexylthiophene) (P3HT) and analyzed its conductivity as response for exposure to dynamic flow of saturated vapors of six VOCs [n -hexane, toluene, chloroform, dichloromethane, methanol, and tetrahydrofuran (THF)]. Different responses were obtained upon exposure to all VOCs, THF gave the higher response while methanol the lower response. The influence of moisture on the measurements was also evaluated. [source] A comparative study on camphorsulphonic acid modified montmorillonite clay based conducting polymer nanocompositesPOLYMER COMPOSITES, Issue 5 2010Ufana Riaz Nanotechnology has emerged as a subject of immense academic interest and excitement in the past few decades. The immediate goal of this science aims at the production of high performance nanomaterials. The present study reports comparative investigations on the in situ polymerization of polyaniline (PANI), and its derivatives poly(1-naphthylamine) (PNA) and poly(o -toluidine) (POT) within the camphor sulphonic acid (CSA) modified montmorillonite (MMT) layers. The polymerization as well as intercalation of the conducting polymers was confirmed by FT-IR, UV-visible spectroscopies, and XRD studies, whereas the morphology of the nanocomposites was analyzed by TEM studies. It was found that the PANI derivatives (PNA and POT) revealed higher intercalation as compared with PANI. The morphology of nanocomposites was found to be governed by the type of conducting polymer intercalated. A large variation in the morphology as well as particle size was observed between the nanocomposites of PANI and its derivatives. The conductivity was found to be in the range of 10,3,10,2 S·cm,1. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers [source] Mathematical modeling for the ionic inclusion process inside conducting polymer-based thin-filmsPOLYMER ENGINEERING & SCIENCE, Issue 11 2008Saptarshi Majumdar Ionic inclusion inside thin conducting polymer (CP) film is a major and common feature for actuator as well as membrane-based drug release. In this study, an electro-active polymeric thin-film system has been conceptualized. PNP-electro-neutrality (Poisson,Nernst, Planck) based modeling framework with customized boundary conditions is used to depict the electrochemical phenomena. In dynamic model, kinetics of probable redox reactions is included along with electro-migration and diffusion terms in the overall PNP framework. At steady state, interfacial voltage seems to hold the critically important role, while ionic migration and reaction kinetics play very crucial roles in determining the dynamics of such systems. The validated model predicts that lowering in the standard potential of the polymeric electrode accelerates the process of ionic ingress. Higher ionic flux is obtained using slower voltage scan. Variation of diffusivity shows the large spectrum of relatively unexplored dynamics for such electro-active thin-film-based system. The significance is in designing actuator- or membrane-based controlled molecular release systems. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source] Electro-synthesized PEDOT/glutamate chemically modified electrode: a combination of electrical and biocompatible featuresPOLYMER INTERNATIONAL, Issue 5 2008Jianfei Che Abstract BACKGROUND: Neural prosthetic devices have been developed that can facilitate the stimulation and recording of electrical activity when implanted in the central nervous system. The key parts of the devices are metal (gold) electrodes; however, surface modification of the gold electrode is desired. Conducting polymers are promising candidates for this purpose. RESULTS: A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was electro-polymerized onto gold electrodes with a neural transmitter of glutamate (Glu) as dopant. A protocol of ion exchange was employed due to the difficulty of direct incorporation of Glu into PEDOT. Sodium p -toluenesulfonate (TSNa) was chosen as the first dopant and subsequent incorporation of Glu was accomplished via ion exchange. The electrochemical properties of the resultant PEDOT/Glu were studied using electrochemical impedance spectroscopy and cyclic voltammetry. The purpose of incorporating Glu was to improve the biocompatibility of the coated electrode. The PEDOT/Glu-coated electrode showed better cell attachment compared with a PEDOT/TSNa-coated electrode in in vitro cell culture of PC12. The stability of PEDOT was studied by immersing the coated electrode in a biologically relevant reducing agent of glutathione. CONCLUSION: The charge capacity of the coated electrode had an initial slight decrease and then remained unchanged. Good electro-activity was conserved, indicating the superior stability of PEDOT in the biological environment. Copyright © 2007 Society of Chemical Industry [source] Synthesis, characterization and properties of azobenzene side-chain polythiophene,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3-5 2003Leong Huat Gan Abstract Thiophene monomers with an azobenzene moiety of different spacer length at the 3-position of the thiophene ring were synthesized. The monomers were polymerized and copolymerized with 3-hexyl thiophene to investigate the influence of an azobenzene side-chain on the properties of polythiophene, which has been widely used as a conducting polymer and has also been found many other applications. The polymers were characterized with UV-vis, FT-IR spectrophotometry, gel permeation chromatographic (GPC) analysis, DSC, TGA, elemental analysis and X-ray diffractometry. The polymers showed novel thermochromic and photoresponsive properties in polymer solutions and solid films. It was found that an azobenzene side-chain could bring about substantial thermochromic and photochromic changes to the polythiophene backbone as compared with non-azobenzene side-chain polythiophenes. These property changes could be triggered or controlled by light or heat on the basis of azobenzene trans,cis or cis,trans isomerization. Copyright © 2003 John Wiley & Sons, Ltd. [source] Electromagnetic interference shielding by using conductive polypyrrole and metal compound coated on fabricsPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 8 2002C. Y. Lee Abstract Electromagnetic interference (EMI) shielding materials of complex type of conductive polypyrrole (PPy) as an intrinsically conducting polymer and silver-palladium (AgPd) metal compound coated on woven or non-woven fabrics are synthesized. From dc conductivity and SEM photographs of PPy/fabric complexes, we discuss charge transport mechanism and the homogeneity of coating on the fabrics. The EMI shielding efficiency of PPy/fabric and AgPd/fabric complexes is in the range of 8,,,80 dB depending on the conductivity and the additional Ag vacuum evaporation. The highest EMI shielding efficiency of PPy/fabric complexes vacuum-evaporated by Ag is ,80 dB, indicating potential materials for military uses. We propose that PPy/fabrics are excellent RF and microwave absorber because of the relatively high absorbance and low reflectance of the materials. Copyright © 2002 John Wiley & Sons, Ltd. [source] Donor/Conductor/Acceptor Triads Spatially Organized on the Micrometer-Length Scale: An Alternative Approach to Photovoltaic CellsCHEMISTRY - A EUROPEAN JOURNAL, Issue 2 2007Francesc Abstract We have used porous anodised Al2O3 membranes as inert matrix for constructing and organizing spatially ternary donor/conductor/acceptor (DCA) systems exhibiting photovoltaic cell activity on the micrometric-length scale. These DCA triads were built stepwise by first growing a conducting polymer inside the membrane pores, thus forming nanorods that completely fill the internal pore space of the membrane. Then, an electron donor and an electron acceptor were adsorbed one on each side of the membrane, so that they were separated by a distance equal to the membrane thickness (ca. 60,,m), but electronically connected through the conductive polymer. When this device was placed between two electrodes and irradiated with visible light, electrons jumped from the donor molecule, crossed the membrane from side to side through the conductive polymer (a journey of about 60,,m!) until they finally reach the acceptor molecule. In so doing, an electric voltage was generated between the two electrodes, capable of maintaining an electric current flow from the membrane to an external circuit. Our DCA device constitutes the proof of a novel concept of photovoltaic cells, since it is based on the spatial organization at the micrometric scale of complementary, but not covalently linked, electron-donor and electron-acceptor organic species. Thus, our cell is based in translating photoinduced electron transfer between donors and acceptors, which is known to occur at the molecular nanometric scale, to the micrometric range in a spatially organised system. In addition our cell does not need the use of liquid electrolytes in order to operate, which is one of the main drawbacks in dye-sensitised solar cells. [source] Chemical Reactivity of Polypyrrole and Its Relevance to Polypyrrole Based Electrochemical SensorsELECTROANALYSIS, Issue 16 2006Krzysztof MaksymiukArticle first published online: 26 JUL 200 Abstract One of the most frequently used conducting polymers, polypyrrole, can take part in chemical processes with typical components of ambient media: oxygen, acids, bases, redox reactants, water, and organic vapors; it can also incorporate nonreactive ions and surfactants from solutions. The influence of such processes on changes of the polymer structure, composition and on possible degradation is analyzed. The benefits and disadvantages of such processes for analytical characteristic of polypyrrole based electrochemical sensors are considered. This discussion is focused on potentiometric ion sensors, where polypyrrole is either a receptor membrane or an ion-to-electron transducer placed between a solid state electrode support and a typical ion-selective membrane. 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