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Conductive Polymers (conductive + polymer)
Terms modified by Conductive Polymers Selected AbstractsOptimization of the Composition of Interfaces in Miniature Planar Chloride ElectrodesELECTROANALYSIS, Issue 15-16 2003Renata Paciorek Abstract Different solid contact arrangements for miniature screen-printed electrodes and silicon based electrodes for chloride ions were investigated. As an inner contact the electrochemically deposited gold on screen-printed silver and platinum (silicon based electrodes) were used. As the ion-exchanger for chloride methyl-tri- n -tetradecylammonium chloride with PVC or Tecoflex as the polymer matrix was used. The influence of different intermediate layers between inner contact and the ion selective membrane was studied. The best characteristic of the electrode was obtained for electrodes containing gold contact and conductive polymer (poly-3-octylthiophene) with adhesive admixture between the inner contact and the proper ion selective membrane. [source] Membrane protected conductive polymer as micro-SPE device for the determination of triazine herbicides in aquatic mediaJOURNAL OF SEPARATION SCIENCE, JSS, Issue 8 2010Habib Bagheri Abstract A micro-SPE technique was developed by fabricating a rather small package including a polypropylene membrane shield containing the appropriate sorbent. The package was used for the extraction of some triazine herbicides from aqueous samples. Solvent desorption was subsequently performed in a microvial and an aliquot of extractant was injected into GC-MS. Various sorbents including aniline- ortho -phenylene diamine copolymer, newly synthesized, polypyrrole, multiwall carbon nanotube, C18 and charcoal were examined as extracting media. Among them, conductive polymers exhibited better performance. Influential parameters including extraction and desorption time, desorption solvent and the ionic strength were optimized. The developed method proved to be rather convenient and offers sufficient sensitivity and good reproducibility. The detection limits of the method under optimized conditions were in the range of 0.01,0.04,ng/mL. The RSDs at a concentration level of 0.1,ng/mL were obtained between 4.5 and 9.3% (n=5). The calibration curves of analytes showed linearity in the range of 0.05,10,ng/mL. The developed method was successfully applied to the extraction of selected triazines from real water samples. The whole procedure showed to be conveniently applicable and quite easy to manipulate. [source] Multistep filling of porous silicon with conductive polymer by electropolymerizationPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2009Kazuhiro Fukami Abstract The filling of porous silicon with polypyrrole by electropolymerization was investigated. The filling with polypyrrole proceeded preferentially along the porous silicon wall, leading to the formation of tubular structures. By repeating the porosification, the pore filling and the additional porosification, through-tubes of polypyrrole were formed in macropores. The technique to form through-tube was also applied to medium-sized pores. A double layer with polypyrrole was produced by the repetition of porosification and pore filling twice. The immobilization of glucose oxidase was performed by electropolymerization in an aqueous solution containing glucose oxidase and pyrrole. Glucose oxidase was immobilized physically in the polypyrrole film. In the double layer, the sensitivity of glucose oxidase was measured by electrochemical oxidation of hydrogen peroxide, which was produced by the enzymatic reaction of glucose oxidase to gluconolactone. When glucose oxidase was immobilized in the upper layer, glucose was detected sensitively. On the other hand, when glucose oxidase was immobilized in the lower layer, the sensing current showed a slow and a low response. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Synthesis and studies of the physical properties of polyaniline and polyurethane-modified epoxy compositesPOLYMER ENGINEERING & SCIENCE, Issue 2 2008Wen-Chin Chiou Two series of toughened, semiconductive polyaniline (PANI)/polyurethane (PU)-epoxy (PANI/PU-EPOXY) nano-composites were prepared using a conductive polymer, PANI, and PU prepolymer-modified-diglycidyl ether of bisphenol A (DGEBA) epoxy. First, the PU prepolymer-modified epoxy oligomer was synthesized by a stoichiometric reaction between the terminal isocyanate groups of the PU prepolymer and the pendent hydroxyl groups of the epoxide. PU prepolymers were made either of polyester (polybutylene adipate, PBA) or polyether (polypropylene glycol, PPG) segments. The composites were characterized by thermal, morphological, mechanical, and electrical studies. Impact strength was enhanced 100% in PU (PPG 2000)-modified composites; whereas, only ca. 30,50% increases in impact strength were observed for the other modified composites. In addition, the thermal stability of this composite proved superior to that of neat epoxy resin, regardless of a PU content at 27.5 wt%. Scanning electron microscopy (SEM) morphology study showed that the spherical PU (PPG 2000) particles (ca. 0.2,0.5 ,m) dispersed within the matrix accounts for these extraordinary properties. The conductivity of the composite increased to ca. 10,9,10,3 S cm,1 upon addition of PANI when tested in the frequency range 1 kHz,13 MHz. This study demonstrated a useful way to simultaneously improve the toughness and conductivity of the epoxy composite, thus rendering it suitable for electromagnetic interference and various charge dissipation applications. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers [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] Large-Area Nanoscale Patterning of Functional Materials by Nanomolding in CapillariesADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Xuexin Duan Abstract Within the past years there has been much effort in developing and improving new techniques for the nanoscale patterning of functional materials used in promising applications like nano(opto)electronics. Here a high-resolution soft lithography technique,nanomolding in capillaries (NAMIC),is demonstrated. Composite PDMS stamps with sub-100,nm features are fabricated by nanoimprint lithography to yield nanomolds for NAMIC. NAMIC is used to pattern different functional materials such as fluorescent dyes, proteins, nanoparticles, thermoplastic polymers, and conductive polymers at the nanometer scale over large areas. These results show that NAMIC is a simple, versatile, low-cost, and high-throughput nanopatterning tool. [source] Initiating electropolymerization on graphene sheets in graphite oxide structureJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2010Ali Eftekhari Abstract Because of its special chemical composition, graphite oxide has peculiar influences on electrochemical processes. The existence of various functional groups significantly affects electropolymerization processes and the formation of conductive polymers. Electrochemical synthesis of polyaniline (as a prototype of conductive polymers) on a paste-based substrate of graphite oxide was investigated. In this case, the electropolymerization is significantly different from conventional cases, and the polymer is generated just during the first potential cycle. This can be attributed to the fact that graphite oxide can assist the monomer oxidation. Alternatively, electropolymerization was successfully performed inside the graphite oxide layers via electrochemical treatment of aniline-intercalated graphite oxide in the supporting electrolyte. Although these phenomena are related to the chemical composition of graphite oxide, the graphite prepared by the reduction of graphite oxide also displayed some advantages for the electropolymerization (over natural graphite). There is an emphasis on the morphological investigations throughout this study, because novel morphologies were observed in the system under investigation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2204,2213, 2010 [source] Membrane protected conductive polymer as micro-SPE device for the determination of triazine herbicides in aquatic mediaJOURNAL OF SEPARATION SCIENCE, JSS, Issue 8 2010Habib Bagheri Abstract A micro-SPE technique was developed by fabricating a rather small package including a polypropylene membrane shield containing the appropriate sorbent. The package was used for the extraction of some triazine herbicides from aqueous samples. Solvent desorption was subsequently performed in a microvial and an aliquot of extractant was injected into GC-MS. Various sorbents including aniline- ortho -phenylene diamine copolymer, newly synthesized, polypyrrole, multiwall carbon nanotube, C18 and charcoal were examined as extracting media. Among them, conductive polymers exhibited better performance. Influential parameters including extraction and desorption time, desorption solvent and the ionic strength were optimized. The developed method proved to be rather convenient and offers sufficient sensitivity and good reproducibility. The detection limits of the method under optimized conditions were in the range of 0.01,0.04,ng/mL. The RSDs at a concentration level of 0.1,ng/mL were obtained between 4.5 and 9.3% (n=5). The calibration curves of analytes showed linearity in the range of 0.05,10,ng/mL. The developed method was successfully applied to the extraction of selected triazines from real water samples. The whole procedure showed to be conveniently applicable and quite easy to manipulate. [source] Dissolution and Doping of Polyaniline Emeraldine Base in Imidazolium Ionic Liquids Investigated by Spectroscopic TechniquesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 5 2007Fabio Rodrigues Abstract Polyaniline is a model molecular system in the study of conductive polymers. Ionic liquids, on the other hand, are becoming more and more a very convenient alternative for conventional organic solvents. The dissolution of polyaniline-emeraldine base (PANI-EB) in imidazolium ILs leads to its doping, as indicated by optical and resonance Raman spectroscopies. In this study, it is proposed that the interaction of PANI-EB and imidazolium ILs involves the specific interaction of the quinoid moiety of the former with the imidazolium ring of the latter, an interpretation that is also based on N K -edge XANES measurements of neat PANI-EB, neat ILs, and of their solutions. [source] Solid-phase microextraction combined with surface-enhanced laser desorption/ionization introduction for ion mobility spectrometry and mass spectrometry using polypyrrole coatingsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 2 2004Yan Wang The successful application of polypyrrole (PPY) solid-phase microextraction (SPME) coatings as both an extraction phase and a surface to enhance laser desorption/ionization (SELDI) of analytes is reported. This SPME/SELDI fiber integrates sample preparation and sample introduction on the tip of a coated optical fiber, as well as acting as the transmission medium for the UV laser light. Using ion mobility spectrometry (IMS) detection, the signal intensity was examined as a function of extraction surface area and concentration of analyte. The linear relationship between concentration and signal intensity shows potential applicability of this detection method for quantitative analysis. Extraction time profiles for the fiber, using tetraoctylammonium bromide as test analyte, illustrated that equilibrium can be reached in less than one minute. To investigate the performance of the PPY coating, the laser desorption profile was studied. The fiber was also tested using a quadrupole time-of-flight (Q-TOF) mass spectrometer with leucine enkephalin as test analyte. Since no matrix was used, mass spectra free from matrix background were obtained. This novel SPME/SELDI fiber is easy to manufacture, and is suitable for studying low-mass analytes because of the intrinsic low background. These findings suggest that other types of conductive polymers could also be used as an extraction phase and surface to enhance laser desorption/ionization in mass spectrometry. Copyright © 2003 John Wiley & Sons, Ltd. [source] Photosynthetic microbial fuel cells with positive light responseBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2009Yongjin Zou Abstract The current study introduces an aerobic single-chamber photosynthetic microbial fuel cell (PMFC). Evaluation of PMFC performance using naturally growing fresh-water photosynthetic biofilm revealed a weak positive light response, that is, an increase in cell voltage upon illumination. When the PMFC anodes were coated with electrically conductive polymers, the rate of voltage increased and the amplitude of the light response improved significantly. The rapid immediate positive response to light was consistent with a mechanism postulating that the photosynthetic electron-transfer chain is the source of the electrons harvested on the anode surface. This mechanism is fundamentally different from the one exploited in previously designed anaerobic microbial fuel cells (MFCs), sediment MFCs, or anaerobic PMFCs, where the electrons are derived from the respiratory electron-transfer chain. The power densities produced in PMFCs were substantially lower than those that are currently reported for conventional MFC (0.95,mW/m2 for polyaniline-coated and 1.3,mW/m2 for polypyrrole-coated anodes). However, the PMFC did not depend on an organic substrate as an energy source and was powered only by light energy. Its operation was CO2 -neutral and did not require buffers or exogenous electron transfer shuttles. Biotechnol. Bioeng. 2009; 104: 939,946. © 2009 Wiley Periodicals, Inc. [source] | |||||||||||||