WorldWideScience

Sample records for nanocrystal conducting polymer

  1. Semiconductor-nanocrystal/conjugated polymer thin films

    Science.gov (United States)

    Alivisatos, A. Paul; Dittmer, Janke J.; Huynh, Wendy U.; Milliron, Delia

    2010-08-17

    The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.

  2. Thermally conductive polymers

    Science.gov (United States)

    Byrd, N. R.; Jenkins, R. K.; Lister, J. L. (Inventor)

    1971-01-01

    A thermally conductive polymer is provided having physical and chemical properties suited to use as a medium for potting electrical components. The polymer is prepared from hydroquinone, phenol, and formaldehyde, by conventional procedures employed for the preparation of phenol-formaldehyde resins. While the proportions of the monomers can be varied, a preferred polymer is formed from the monomers in a 1:1:2.4 molar or ratio of hydroquinone:phenol:formaldehyde.

  3. Thermal conductivity of silicon nanocrystals and polystyrene nanocomposite thin films

    Science.gov (United States)

    Bagja Juangsa, Firman; Muroya, Yoshiki; Ryu, Meguya; Morikawa, Junko; Nozaki, Tomohiro

    2016-09-01

    Silicon nanocrystals (SiNCs) are well known for their size-dependent optical and electronic properties; they also have the potential for low yet controllable thermal properties. As a silicon-based low-thermal conductivity material is required in microdevice applications, SiNCs can be utilized for thermal insulation. In this paper, SiNCs and polymer nanocomposites were produced, and their thermal conductivity, including the density and specific heat, was measured. Measurement results were compared with thermal conductivity models for composite materials, and the comparison shows a decreasing value of the thermal conductivity, indicating the effect of the size and presence of the nanostructure on the thermal conductivity. Moreover, employing silicon inks at room temperature during the fabrication process enables a low cost of fabrication and preserves the unique properties of SiNCs.

  4. 'Stuffed' conducting polymers

    DEFF Research Database (Denmark)

    Winther-Jensen, Bjørn; Chen, Jun; West, Keld;

    2005-01-01

    Conducting polymers (CP) obtained by oxidative polymerization using iron(III) salts shrink when Fe(II) and the excess counter ions are washed out after polymerization. This phenomenon can be used to incorporate active molecules into the CP matrix via their addition to the wash liquid. In the pres......Conducting polymers (CP) obtained by oxidative polymerization using iron(III) salts shrink when Fe(II) and the excess counter ions are washed out after polymerization. This phenomenon can be used to incorporate active molecules into the CP matrix via their addition to the wash liquid....... In the present work we demonstrate this principle on three different CP's: polypyrrole (PPy), poly-terthiophene (PTTh) and poly(3,4-ethylenedioxy thiophene) (PEDT), using ferrocene as a model molecule to be trapped in the polymer films. (c) 2005 Elsevier Ltd. All rights reserved....

  5. Conductive Polymer Composites

    OpenAIRE

    Pierini, Filippo

    2013-01-01

    In recent years, nanotechnologies have led to the production of materials with new and sometimes unexpected qualities through the manipulation of nanoscale components. This research aimed primarily to the study of the correlation between hierarchical structures of hybrid organic-inorganic materials such as conductive polymer composites (CPCs). Using a bottom-up methodology, we could synthesize a wide range of inorganic nanometric materials with a high degree of homogeneity and purity, ...

  6. Semiconductor nanocrystals in photoconductive polymers: Charge generation and charge transport

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Herron, Norman; Suna, A. [Du Pont Co., Wilmington, DE (United States)

    1996-10-01

    A new class of photoconductive polymer composites, based on semiconductor nanocrystals (clusters) and carder-transporting polymers, have been developed. These materials are interesting for their potentials in laser printing, imaging, and photorefractives. We will describe material synthesis, charge transport and charge generation mechanisms. In particular, a model of field-dependent charge generation and separation in nonpolar media (e.g. polymers) will be discussed.

  7. Conducting Polymer Based Nanobiosensors

    Directory of Open Access Journals (Sweden)

    Chul Soon Park

    2016-06-01

    Full Text Available In recent years, conducting polymer (CP nanomaterials have been used in a variety of fields, such as in energy, environmental, and biomedical applications, owing to their outstanding chemical and physical properties compared to conventional metal materials. In particular, nanobiosensors based on CP nanomaterials exhibit excellent performance sensing target molecules. The performance of CP nanobiosensors varies based on their size, shape, conductivity, and morphology, among other characteristics. Therefore, in this review, we provide an overview of the techniques commonly used to fabricate novel CP nanomaterials and their biosensor applications, including aptasensors, field-effect transistor (FET biosensors, human sense mimicking biosensors, and immunoassays. We also discuss prospects for state-of-the-art nanobiosensors using CP nanomaterials by focusing on strategies to overcome the current limitations.

  8. Synthesis of Doped Semiconductor Nanocrystals and Conductive Coatings

    Science.gov (United States)

    Wills, Andrew Wilke

    measurements reveal that the nanocrystal Fermi level rises with increasing Al content. The third thrust is achieved by the use of primary dithiocarbamates as ligands to stabilize CdSe, and PbSe / CdSe core/shell nanoparticles. Primary dithiocarbamates bind well to metals but include a weak chemical bond that can be broken with gentle heating. This enables us to bind them to nanoparticles, process the particles into devices, then remove the ligand via gentle heating. Characterization of the ligand-particle interactions show excellent ligand binding to the particle surface and easy ligand removal with heating. After ligand removal, the inter-particle spacing shrinks. Transistor measurements reveal that this reduces the barrier to interparticle electron transport, enhancing the conductivity of the film.

  9. Conductive polymer-based material

    Science.gov (United States)

    McDonald, William F.; Koren, Amy B.; Dourado, Sunil K.; Dulebohn, Joel I.; Hanchar, Robert J.

    2007-04-17

    Disclosed are polymer-based coatings and materials comprising (i) a polymeric composition including a polymer having side chains along a backbone forming the polymer, at least two of the side chains being substituted with a heteroatom selected from oxygen, nitrogen, sulfur, and phosphorus and combinations thereof; and (ii) a plurality of metal species distributed within the polymer. At least a portion of the heteroatoms may form part of a chelation complex with some or all of the metal species. In many embodiments, the metal species are present in a sufficient concentration to provide a conductive material, e.g., as a conductive coating on a substrate. The conductive materials may be useful as the thin film conducting or semi-conducting layers in organic electronic devices such as organic electroluminescent devices and organic thin film transistors.

  10. Conducting Polymers: Emerging Commercial Materials

    Directory of Open Access Journals (Sweden)

    N. Kumar

    1996-04-01

    Full Text Available Conducting polymers are materials of recent origin. They are obtained by polymerisation of simple organic monomers and doping with electron acceptor or donor species and show conductivity ranging from that of a semiconductor to that of metal. These materials are now available with unique electronic and optical properties of metals and semiconductors in combination with the attractive mechanical and processable advantages of polymers. The field has progressed to a level of maturity consistent with a new set of opportunities to develop Wide range of applications based upon conducting polymers as materials for industrial products.Examples include: static charge dissipation, EMI shielding, flexible light emitting diodes, transparent electrodes, batteries, gas sensors, gas separators, etc. Many of the conducting polymers and devices based on them are now available commercially.

  11. Conducting Polymers: Emerging Commercial Materials

    OpenAIRE

    Kumar, N; S. R. Vadera; Jeevan Singh; Das, G.; S. C. Negi; Aparna, P.; Tuli, A

    1996-01-01

    Conducting polymers are materials of recent origin. They are obtained by polymerisation of simple organic monomers and doping with electron acceptor or donor species and show conductivity ranging from that of a semiconductor to that of metal. These materials are now available with unique electronic and optical properties of metals and semiconductors in combination with the attractive mechanical and processable advantages of polymers. The field has progressed to a level of maturity cons...

  12. Conducting polymer 3D microelectrodes

    DEFF Research Database (Denmark)

    Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi;

    2010-01-01

    Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained...... showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared...... with electrodes coated with only metal. An electrochemical characterization of gold/polypyrrole electrodes showed exceptional electrochemical behavior and activity. PC12 cells were finally cultured on the investigated materials as a preliminary biocompatibility assessment. These results show that the described...

  13. Conducting Polymer 3D Microelectrodes

    Directory of Open Access Journals (Sweden)

    Jenny Emnéus

    2010-12-01

    Full Text Available Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared with electrodes coated with only metal. An electrochemical characterization of gold/polypyrrole electrodes showed exceptional electrochemical behavior and activity. PC12 cells were finally cultured on the investigated materials as a preliminary biocompatibility assessment. These results show that the described electrodes are possibly suitable for future in-vitro neurological measurements.

  14. Multifunctional Composites Obtained by Incorporating Nanocrystals into Decorated PVK Polymers

    Directory of Open Access Journals (Sweden)

    Haizhu Sun

    2007-01-01

    Full Text Available Poly(vinylcarbazole (PVK was decorated with surfactant group to achieve amphiphilic polymer with luminescent property. The composition and properties of the polymers were systematically investigated using FTIR, EA, TGA, UV-Vis, and PL characterizations. Different CdTe nanocrystals (NCs prepared in aqueous medium were directly transferred to organic phase using the PVK-based polymers. The quantum yield of NCs in the composites had been improved by 50% compared with their parent aqueous solution due to the short distance from carbazole moieties to NCs, which facilitated the Förster resonant energy transfer (FRET between them. Moreover, efficient electron transfer at the interface of NCs and polymers had been confirmed which also indicated the application in photovoltaic cell for such composites.

  15. Conjugated polymer/nanocrystal nanocomposites for renewable energy applications in photovoltaics and photocatalysis.

    Science.gov (United States)

    Su, Yu-Wei; Lin, Wei-Hao; Hsu, Yung-Jung; Wei, Kung-Hwa

    2014-11-01

    Conjugated polymer/nanocrystal composites have attracted much attention for use in renewable energy applications because of their versatile and synergistic optical and electronic properties. Upon absorbing photons, charge separation occurs in the nanocrystals, generating electrons and holes for photocurrent flow or reduction/oxidation (redox) reactions under proper conditions. Incorporating these nanocrystals into conjugated polymers can complement the visible light absorption range of the polymers for photovoltaics applications or allow the polymers to sensitize or immobilize the nanocrystals for photocatalysis. Here, the current developments of conjugated polymer/nanocrystal nanocomposites for bulk heterojunction-type photovoltaics incorporating Cd- and Pb-based nanocrystals or quantum dots are reviewed. The effects of manipulating the organic ligands and the concentration of the nanocrystal precursor, critical factors that affect the shape and aggregation of the nanocrystals, are also discussed. In the conclusion, the mechanisms through which conjugated polymers can sensitize semiconductor nanocrystals (TiO2 , ZnO) to ensure efficient charge separation, as well as how they can support immobilized nanocrystals for use in photocatalysis, are addressed.

  16. INFRARED EMISSIVITY OF CONDUCTING POLYMERS

    Institute of Scientific and Technical Information of China (English)

    WAN Meixiang; LI Suzhen; LI Junchao; DONG Haiou

    1991-01-01

    The infrared emissivity of conducting polymers in 8-20μm and at 50-150℃ in the direction of normal line has been measured as a function of wavelength, conductivity at room temperature,counterion, doping levels, measuring temperature and thickness of sample.

  17. Preparation of CdTe nanocrystal-polymer composite microspheres in aqueous solution by dispersing method

    Institute of Scientific and Technical Information of China (English)

    LI Minjie; WANG Chunlei; HAN Kun; YANG Bai

    2005-01-01

    Highly fluorescent CdTe nanocrystals were synthesized in aqueous solution, and then processible CdTe nanocrystal-polymer composites were fabricated by coating the aqueous nanocrystals with copolymers of styrene and octadecyl-p-vinyl-benzyldimethylammonium chloride (SOV- DAC) directly. A dichloromethane solution of CdTe nano- crystal-polymer composites was dispersed in the aqueous solution of poly (vinyl alcohol) (PVA) generating highly fluorescent microspheres. Experimental parameters such as the concentration of nanocrystal-polymer composites, the concentration of PVA, and stirring speed which had important effect on the preparation of the microspheres were investigated in detail with fluorescent microscope characterization.

  18. Ultrabroadband terahertz conductivity of Si nanocrystal films

    DEFF Research Database (Denmark)

    Cooke, D. G.; Meldrum, A.; Jepsen, P. Uhd

    2012-01-01

    The terahertz conductivity of silicon nanoparticles embedded in glass with varying density is studied with ultra-broadband terahertz spectroscopy on picosecond time scales following fs optical excitation. The transition from relatively isolated charge carriers to densities which allow inter...... the applicability of this simple model to the conductivity of nanoparticle ensembles over the entire THz spectral window....

  19. Nanocrystal-polymer nanocomposite electrochromic device

    Science.gov (United States)

    Milliron, Delia; Runnerstrom, Evan; Helms, Brett; Llordes, Anna; Buonsanti, Raffaella; Garcia, Guillermo

    2015-12-08

    Described is an electrochromic nanocomposite film comprising a solid matrix of an oxide based material, the solid matrix comprising a plurality of transparent conducting oxide (TCO) nanostructures dispersed in the solid matrix and a lithium salt dispersed in the solid matrix. Also described is a near infrared nanostructured electrochromic device having a functional layer comprising the electrochromic nanocomposite film.

  20. The Workshop on Conductive Polymers: Final Report

    Science.gov (United States)

    1985-10-01

    Reports are made by groups on: polyacetylene, polyphenylene, polyaniline, and related systems; molecular, crystallographic, and defect structures in conducting polymers; heterocyclic polymers; synthesis of new and improved conducting polymers; future applications possibilities for conducting polymers; and challenges for improved understanding of properties. (DLC)

  1. Water-soluble conductive polymers

    Science.gov (United States)

    Aldissi, Mahmoud

    1989-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  2. Aqueous-Processed Insulating Polymer/Nanocrystal Hybrid Solar Cells.

    Science.gov (United States)

    Jin, Gan; Chen, Zhaolai; Dong, Chunwei; Cheng, Zhongkai; Du, Xiaohang; Zeng, Qingsen; Liu, Fangyuan; Sun, Haizhu; Zhang, Hao; Yang, Bai

    2016-03-23

    A novel kind of hybrid solar cell (HSC) was developed by introducing water-soluble insulating polymer poly(vinyl alcohol) (PVA) into nanocrystals (NCs), which revealed that the most frequently used conjugated polymer could be replaced by an insulating one. It was realized by strategically taking advantage of the characteristic of decomposition for the polymer at annealing temperature, and it was interesting to discover that partial decomposition of PVA left behind plenty of pits on the surfaces of CdTe NC films, enlarging surface contact area between CdTe NCs and subsequently evaporated MoO3. Moreover, the residual annealed PVA filled in the voids among spherical CdTe NCs, which led to the decrease of leakage current. An improved shunt resistance (increased by ∼80%) was achieved, indicating the charge-carrier recombination was effectively overcome. As a result, the new HSCs were endowed with increased Voc, fill factor, and power conversion efficiency compared with the pure NC device. This approach can be applied to other insulating polymers (e.g., PVP) with advantages in synthesis, type, economy, stability, and so on, providing a novel universal cost-effective way to achieve higher photovoltaic performance. PMID:26931540

  3. Conductivity behaviour of polymer gel electrolytes: Role of polymer

    Indian Academy of Sciences (India)

    S S Sekhon

    2003-04-01

    Polymer is an important constituent of polymer gel electrolytes along with salt and solvent. The salt provides ions for conduction and the solvent helps in the dissolution of the salt and also provides the medium for ion conduction. Although the polymer added provides mechanical stability to the electrolytes yet its effect on the conductivity behaviour of gel electrolytes as well as the interaction of polymer with salt and solvent has not been conclusively established. The conductivity of lithium ion conducting polymer gel electrolytes decreases with the addition of polymer whereas in the case of proton conducting polymer gel electrolytes an increase in conductivity has been observed with polymer addition. This has been explained to be due to the role of polymer in increasing viscosity and carrier concentration in these gel electrolytes.

  4. Electrically conducting polymers for aerospace applications

    Science.gov (United States)

    Meador, Mary Ann B.; Gaier, James R.; Good, Brian S.; Sharp, G. R.; Meador, Michael A.

    1991-01-01

    Current research on electrically conducting polymers from 1974 to the present is reviewed focusing on the development of materials for aeronautic and space applications. Problems discussed include extended pi-systems, pyrolytic polymers, charge-transfer systems, conductive matrix resins for composite materials, and prospects for the use of conducting polymers in space photovoltaics.

  5. Electrochemical Study of Conductive Gel Polymer

    Institute of Scientific and Technical Information of China (English)

    Zhaohui Li; Jing Jiang; Gangtie Lei

    2005-01-01

    @@ 1Introduction Conventional ion-conducting polymer consists of electrolyte salt and polymer matrix, so-called salt-inpolymer. It possesses lower conductivity because the migration of ions depends on the motion of polymer segmental. To increase the ionic conductivity, a kind of gel polymer film (GPF) was prepared by in situ polymerization of methyl methacrylate (MMA) monomer in room-temperature ionic liquid(RTIL), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6). Due to immeasurably low vapor pressure, high ionic conductivity, and greater thermal and electrochemical stability, BMIPF6 is suitable electrolyte salts for ion-conducting polymer.

  6. STUDIES ON ENHANCED CONDUCTIVITY OF STRETCHED CONDUCTING POLYMERS

    Institute of Scientific and Technical Information of China (English)

    WAN Meixiang

    1995-01-01

    A physical model of series of the conductivity on chain and the interchain conductivity between chains is proposed to explain enhanced conductivity of stretched conducting polymers.This model suggests that the enhanced conductivity for stretched conducting polymers might be due to increasing of the interchain conductivity between chains along the elongation direction after drawing processes if the conductivity on chain is assumed much larger than that of the interchain conductivity between chains. According to this model, it is expected that the temperature dependence of conductivity measured by four-probe method for stretched conducting polymers is controlled by a variation of the interchain conductivity between chains with temperature, which can be used to explain that a metallic temperature dependence of conductivity for stretched conducting polymers is not observed although the conductivity along the elongation direction is enhanced by two or three orders of magnitude.

  7. Molecular and supramolecular orientation in conducting polymers

    International Nuclear Information System (INIS)

    Intrinsic anisotropy in electrical and optical properties of conducting polymers constitutes a unique aspect that derives π-electron delocalization along the polymer backbone and from the weak inter-chain interaction. To acquire such an intrinsic property, conducting polymers have to be oriented macroscopically and microscopically (at the chain level). A review of the various techniques, including stretch-alignment of the polymer and of precursor polymers, polymerization in ordered media, i.e., in a liquid crystal solvent, and synthesis of liquid crystalline conducting polymers will be given. 29 refs

  8. A merocyanine-based conductive polymer

    OpenAIRE

    Wagner, Klaudia; Zanoni, Michele; Elliott, Anastasia B. S.; Wagner, Pawel; Byrne, Robert; Florea, Larisa; Diamond, Dermot; Gordon, Keith; Wallace, Gordon; Officer, David

    2013-01-01

    We report the first example of a conducting polymer with a merocyanine incorporated into the polymer backbone by electropolymerisation of a spiropyran moiety covalently linked between two alkoxythiophene units. Utilising the known metal coordination capabilities of merocyanines, introduction of cobalt ions into the electropolymerisation led to an enhancement of the conductivity, morphology and optical properties of the polymer films.

  9. A Platform for Functional Conductive Polymers

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hoffmann, Christian; Lind, Johan Ulrik;

    Conductive polymers have been studied extensively during recent years. In order to broaden the application field of conductive polymers different methods have been tested and recently an azide functional poly(3,4-ethylenedioxythiophene) (PEDOT-N3) was developed(1, 2). The azide functional...... conductive polymer can be postpolymerization functionalized to introduce a large number of functionalities through click chemistry(3). Through selection of reaction conditions it is possible control the depth of the reaction into the polymer film to the upper surface or the entire film(4). Thus a conductive...... polymer can be prepared with a subsurface layer of highly conductive polymer where only the upper surface has been grafted with functional groups to ensure selectivity of the surface layer for e.g. interaction with specific biospecies. The conductive polymer can be patterned using selective etching, which...

  10. Conducting Polymers for Neutron Detection

    Energy Technology Data Exchange (ETDEWEB)

    Kimblin, Clare; Miller, Kirk; Vogel, Bob; Quam, Bill; McHugh, Harry; Anthony, Glen; Mike, Grover

    2007-12-01

    Conjugated polymers have emerged as an attractive technology for large-area electronic applications. As organic semiconductors, they can be used to make large-area arrays of diodes or transistors using fabrication techniques developed for polymer coatings, such as spraying and screen-printing. We have demonstrated both neutron and alpha detection using diodes made from conjugated polymers and have done preliminary work to integrate a boron carbide layer into the conventional polymer device structure to capture thermal neutrons. The polymer devices appear to be insensitive to gamma rays, due to their small physical thickness and low atomic number.

  11. Application potential of conducting polymers

    International Nuclear Information System (INIS)

    Intrinsically conducting polymers (ICPs) represent a special class of weak materials with electronic and ionic conductivity. Chemical and physical properties are dependent on their redox state. These properties allow a wide application as functional coatings. At constant film conditions, ICPs can be used in the dry or wet state due to their electronic conductivity, due to their porous structure or due to their processibility in microstructuring processes. The production of conducting electrodes on electrolyte condensers and the through hole plating of printed circuit boards (PCBs) represent typical examples. In sensors and membranes, the pore structure is applied. The application of variable properties, however, is of much greater interest. It is based on the change of charge, electronic states, chemical composition and mechanical properties during the reversible redox process. In contrast to original expectations, small intercalation factors hinder the application in batteries or supercaps. For OLEDs, however, most problems seem to be solved. Application of switching hydrophilic/hydrophobic properties is proved for offset printing but not yet applied. Usually, the anodic doping is investigated. The correspondent cathodic doping opens additional applications. The application of ICPs in functional coatings requires special properties such as fast response (e.g. in ms), stability for 103 cycles for batteries and 106 switches for displays, and a constant potential of discharge for batteries. Moreover, the stability against corrosion, overoxidation and delamination has to be guaranteed. Chemical modification of the monomer allows wide variations of properties, but economic requirements limit the price of the monomer and, thereby, the thickness or quality of the coating

  12. Research Update: Preserving the photoluminescence efficiency of near infrared emitting nanocrystals when embedded in a polymer matrix

    Directory of Open Access Journals (Sweden)

    Olga Solomeshch

    2016-04-01

    Full Text Available Near infrared light emitting nanocrystals are known to lose efficiency when embedded in a polymer matrix. One of the factors leading to reduced efficiency is the labile nature of the ligands that may desorb off the nanocrystal surface when the nanocrystals are in the polymer solution. We show that adding trioctylphosphine to the nanocrystal-poly(methylmethacrylate solution prior to film casting enhances the photoluminescence efficiency. The solid films’ photoluminescence quantum efficiency values are reduced by less than a factor of two in the solid form compared to the solution case. We demonstrate record efficiency values of 25% for lead sulfide nanocrystals solid films emitting at 1100 nm.

  13. Research Update: Preserving the photoluminescence efficiency of near infrared emitting nanocrystals when embedded in a polymer matrix

    Science.gov (United States)

    Solomeshch, Olga; Tessler, Nir

    2016-04-01

    Near infrared light emitting nanocrystals are known to lose efficiency when embedded in a polymer matrix. One of the factors leading to reduced efficiency is the labile nature of the ligands that may desorb off the nanocrystal surface when the nanocrystals are in the polymer solution. We show that adding trioctylphosphine to the nanocrystal-poly(methylmethacrylate) solution prior to film casting enhances the photoluminescence efficiency. The solid films' photoluminescence quantum efficiency values are reduced by less than a factor of two in the solid form compared to the solution case. We demonstrate record efficiency values of 25% for lead sulfide nanocrystals solid films emitting at 1100 nm.

  14. Nanostructured polymer membranes for proton conduction

    Science.gov (United States)

    Balsara, Nitash Pervez; Park, Moon Jeong

    2013-06-18

    Polymers having an improved ability to entrain water are characterized, in some embodiments, by unusual humidity-induced phase transitions. The described polymers (e.g., hydrophilically functionalized block copolymers) have a disordered state and one or more ordered states (e.g., a lamellar state, a gyroid state, etc.). In one aspect, the polymers are capable of undergoing a disorder-to-order transition while the polymer is exposed to an increasing temperature at a constant relative humidity. In some aspects the polymer includes a plurality of portions, wherein a first portion forms proton-conductive channels within the membrane and wherein the channels have a width of less than about 6 nm. The described polymers are capable of entraining and preserving water at high temperature and low humidity. Surprisingly, in some embodiments, the polymers are capable of entraining greater amounts of water with the increase of temperature. The polymers can be used in Polymer Electrolyte Membranes in fuel cells.

  15. Alkyl Passivation and Amphiphilic Polymer Coating of Silicon Nanocrystals for Diagnostic Imaging

    Science.gov (United States)

    Hessel, Colin M.; Rasch, Michael R.; Hueso, Jose L.; Goodfellow, Brian W.; Akhavan, Vahid A.; Puvanakrishnan, Priyaveena; Tunnell, James W.

    2011-01-01

    We show a method to produce biocompatible polymer-coated silicon (Si) nanocrystals for medical imaging. Silica-embedded Si nanocrystals are formed by HSQ thermolysis. The nanocrystals are then liberated from the oxide and terminated with Si-H bonds by HF etching, followed by alkyl monolayer passivation by thermal hydrosilylation. The Si nanocrystals have an average diameter of 2.1 ± 0.6 nm and photoluminesce (PL) with a peak emission wavelength of 650 nm, which lies within the transmission window of 650–900 nm that is useful for biological imaging. The hydrophobic Si nanocrystals are then coated with an amphiphilic polymer for dispersion in aqueous media with pH ranging between 7 and 10 and ionic strength between 30 mM and 2 M, while maintaining a bright and stable PL and a hydrodynamic radius of only 20 nm. Fluorescence imaging of polymer-coated Si nanocrystals in a biological tissue host is demonstrated, showing the potential for in vivo imaging. PMID:20818646

  16. Metal-containing conducting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, S. (Dept. of Chemistry, Univ. of St. Andrews, Fife (United Kingdom)); Crayston, J.A. (Dept. of Chemistry, Univ. of St. Andrews, Fife (United Kingdom))

    1993-03-22

    Poly-(2,6-di-(2-thienyl) pyridine) was investigated for its ability to complex to metals via the pyridine group. Ag[sup +], Cu[sup 2+] and Pd[sup 2+] were reducible in MeCN at the polymer coated electrode after it had been activated by cathodic potentials. The polymer was insulating in aqueous media but in MeCN the cation Ru[sub 3]O(OAc)[sub 6](py)[sub 2](MeOH)[sup +], py=pyridine, was adsorbed onto the polymer as a monolayer. (orig.)

  17. ELECTRICALLY CONDUCTIVE POLYMER-POLYMER COMPOSITES

    OpenAIRE

    Galvin, M; Wnek, G.

    1983-01-01

    Conductive composites have been prepared by polymerization of acelene in polyethylene films followed by iodine doping. The attainment of high conductivity (5-10 S/cm) at low (CH)x concentrations (∼3 wt%) is explained with a simple percolation model.

  18. Colloidal transparent conducting oxide nanocrystals: A new infrared plasmonic material

    Indian Academy of Sciences (India)

    Bharat Tandon; Aswathi Ashok; Angshuman Nag

    2015-06-01

    Thin films of transparent conducting oxides (TCO) are technologically important for applications as a visible light transparent electrode in a wide variety of optoelectronic devices. In the last few years, researchers started to explore novel size- and shape-dependent properties of TCO, where the crystallite size is ∼10 nm. So far, the localized surface plasmon resonance (LSPR) properties of TCO nanocrystals (NCs) have been found to be the most interesting. TCOs like Sn-doped In2O3, Al-doped ZnO and In-doped CdO NCs, exhibit LSPR band in near- to mid-infrared region. LSPR from a TCO NC exhibits many intrinsic differences with that of a metal NC. Carrier density in a TCO NC can easily be tuned by controlling the dopant concentration, which allows the LSPR band to be tuned over a range of ∼2000 nm (∼0.62 eV) in the near- to mid-infrared region. This review discusses recent advances in the understanding of plasmonic properties of various TCO NCs and highlights the potential applications of such unique plasmonic properties.

  19. Biochemical synthesis of water soluble conducting polymers

    Science.gov (United States)

    Bruno, Ferdinando F.; Bernabei, Manuele

    2016-05-01

    An efficient biomimetic route for the synthesis of conducting polymers/copolymers complexed with lignin sulfonate and sodium (polystyrenesulfonate) (SPS) will be presented. This polyelectrolyte assisted PEG-hematin or horseradish peroxidase catalyzed polymerization of pyrrole (PYR), 3,4 ethyldioxithiophene (EDOT) and aniline has provided a route to synthesize water-soluble conducting polymers/copolymers under acidic conditions. The UV-vis, FTIR, conductivity and cyclic voltammetry studies for the polymers/copolymer complex indicated the presence of a thermally stable and electroactive polymers. Moreover, the use of water-soluble templates, used as well as dopants, provided a unique combination of properties such as high electronic conductivity, and processability. These polymers/copolymers are nowadays tested/evaluated for antirust features on airplanes and helicopters. However, other electronic applications, such as photovoltaics, for transparent conductive polyaniline, actuators, for polypyrrole, and antistatic films, for polyEDOT, will be proposed.

  20. Morphology in electrochemically grown conducting polymer films

    Science.gov (United States)

    Rubinstein, Israel; Gottesfeld, Shimshon; Sabatani, Eyal

    1992-01-01

    A conducting polymer film with an improved space filling is formed on a metal electrode surface. A self-assembling monolayer is formed directly on the metal surface where the monolayer has a first functional group that binds to the metal surface and a second chemical group that forms a chemical bonding site for molecules forming the conducting polymer. The conducting polymer is then conventioonally deposited by electrochemical deposition. In one example, a conducting film of polyaniline is formed on a gold electrode surface with an intermediate monolayer of p-aminothiophenol.

  1. Conductive polymer/superconductor bilayer structures

    International Nuclear Information System (INIS)

    The preparation of a hybrid conducting polymer/high-temperature superconductor device consisting of a polypyrrole-coated YBa2Cu3O7-∂ microbridge is reported. Electrochemical techniques are exploited to alter the oxidation state of the polymer and, in doing so, it is found for the first time that superconductivity can be modulated in a controllable and reproducible fashion by a polymer layer. Whereas the neutral (insulating) polypyrrole only slightly influences the electrical properties of the underlying YBa2Cu3O7-∂ film, the oxidized (conductive) polymer depresses Tc by up to 50K. In a similar fashion, the oxidation state of the polymer is found to modulate reversibly the magnitude of Jc, the superconducting critical current. Thus, a new type of molecular switch for controlling superconductivity is demonstrated. Electrochemical, resistance vs. temperature, conact resistance, atomic force microscopy and scanning electron microscopy measurements are utilized to explore the polymer/superconductor interactions

  2. How Fast Should Polymer/Drug Nanocrystal Dispersions Be Frozen?

    Science.gov (United States)

    Lee, Jonghwi; Park, Chul Ho

    2006-03-01

    Recent advances in nanoparticle technologies have significantly enhanced the oral and parenteral delivery of poorly water-soluble active pharmaceutical ingredients (APIs). However, reports have been limited on the various drying procedures to convert a liquid nanocrystal dispersions into solid dosage forms. The solid dosage form should consist of nanocrystals that can readily reconstitute into their original size upon dissolution in water. Herein, the freeze drying process of nanocrystal dispersions was examined at varying freezing rates (speed of freezing interface). As freezing rate decreases, more particle-particle aggregation developed. A critical freezing rate, below which the dried nanocrystals cannot be re-dispersed, was identified based on the plot of the particle size of reconstituted nanocrystals versus freezing rate. Freeze drying at a freezing rate near the critical value produces dry powders of bimodal particle size distribution after re-dispersion. In addition, API concentration was found to significantly affect the critical freezing rate and therefore the re-dispersibility of dry powders. The concept of critical freezing rate is critical for the development of solid dosage forms of liquid nanocrystal dispersions. [1] J. Lee, Drug nano- and microparticles processed into solid dosage forms: physical properties, J. Pharm. Sci., 92(10) (2003) 2057-2068.

  3. Electronically conducting polymers with silver grains

    Science.gov (United States)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor); Hodko, Dolibor (Inventor)

    1999-01-01

    The present invention provides electronically conducting polymer films formed from photosensitive formulations of pyrrole and an electron acceptor that have been selectively exposed to UV light, laser light, or electron beams. The formulations may include photoinitiators, flexibilizers, solvents and the like. These solutions can be used in applications including printed circuit boards and through-hole plating and enable direct metallization processes on non-conducting substrates. After forming the conductive polymer patterns, a printed wiring board can be formed by sensitizing the polymer with palladium and electrolytically depositing copper.

  4. Gyroid nanoporous scaffold for conductive polymers

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Schulte, Lars; Zhang, Weimin;

    2011-01-01

    Conductive nanoporous polymers with interconnected large surface area have been prepared by depositing polypyrrole onto nanocavity walls of nanoporous 1,2-polybutadiene films with gyroid morphology. Vapor phase polymerization of pyrrole was used to generate ultrathin films and prevent pore blocking....... The resulting nanoporous polymers exhibited a promising electroactivity....

  5. Conducting polymer based biomolecular electronic devices

    Indian Academy of Sciences (India)

    B D Malhotra; Rahul Singhal

    2003-08-01

    Biomolecular electronics is rapidly evolving from physics, chemistry, biology, electronics and information technology. Organic materials such as proteins, pigments and conducting polymers have been considered as alternatives for carrying out the functions that are presently being performed by semiconductor silicon. Conducting polymers such as polypyrroles, polythiophenes and polyanilines have been projected for applications for a wide range of biomolecular electronic devices such as optical, electronic, drug-delivery, memory and biosensing devices. Our group has been actively working towards the application of conducting polymers to Schottky diodes, metal–insulator–semiconductor (MIS) devices and biosensors for the past 10 years. This paper is a review of some of the results obtained at our laboratory in the area of conducting polymer biomolecular electronics.

  6. Conjugated polymers/semiconductor nanocrystals hybrid materials--preparation, electrical transport properties and applications.

    Science.gov (United States)

    Reiss, Peter; Couderc, Elsa; De Girolamo, Julia; Pron, Adam

    2011-02-01

    This critical review discusses specific preparation and characterization methods applied to hybrid materials consisting of π-conjugated polymers (or oligomers) and semiconductor nanocrystals. These materials are of great importance in the quickly growing field of hybrid organic/inorganic electronics since they can serve as active components of photovoltaic cells, light emitting diodes, photodetectors and other devices. The electronic energy levels of the organic and inorganic components of the hybrid can be tuned individually and thin hybrid films can be processed using low cost solution based techniques. However, the interface between the hybrid components and the morphology of the hybrid directly influences the generation, separation and transport of charge carriers and those parameters are not easy to control. Therefore a large variety of different approaches for assembling the building blocks--conjugated polymers and semiconductor nanocrystals--has been developed. They range from their simple blending through various grafting procedures to methods exploiting specific non-covalent interactions between both components, induced by their tailor-made functionalization. In the first part of this review, we discuss the preparation of the building blocks (nanocrystals and polymers) and the strategies for their assembly into hybrid materials' thin films. In the second part, we focus on the charge carriers' generation and their transport within the hybrids. Finally, we summarize the performances of solar cells using conjugated polymer/semiconductor nanocrystals hybrids and give perspectives for future developments.

  7. Molecular-Level Switching of Polymer/Nanocrystal Non-Covalent Interactions and Application in Hybrid Solar Cells

    OpenAIRE

    Giansante, Carlo; Mastria, Rosanna; Lerario, Giovanni; Moretti, Luca; Kriegel, Ilka; Scotognella, Francesco; Lanzani, Guglielmo; Carallo, Sonia; Esposito, Marco; Biasiucci, Mariano; Rizzo, Aurora; Gigli, Giuseppe

    2013-01-01

    Hy brid composites obtained upon blending conjugated polymers and colloidal inorganic semiconductor nanocrystals are regarded as attractive photo-active materials for optoelectronic applications. Here we demonstrate that tailoring nanocrystal surface chemistry permits to exert control on non-covalent bonding and electronic interactions between organic and inorganic components. The pendant moieties of organic ligands at the nanocrystal surface do not merely confer colloidal stability while hin...

  8. Processing of Polymer Nanocomposites Reinforced with Polysaccharide Nanocrystals

    Directory of Open Access Journals (Sweden)

    Alain Dufresne

    2010-06-01

    Full Text Available Aqueous suspensions of polysaccharide (cellulose, chitin or starch nanocrystals can be prepared by acid hydrolysis of biomass. The main problem with their practical use is related to the homogeneous dispersion of these nanoparticles within a polymeric matrix. Water is the preferred processing medium. A new and interesting way for the processing of polysaccharide nanocrystals-based nanocomposites is their transformation into a co-continuous material through long chain surface chemical modification. It involves the surface chemical modification of the nanoparticles based on the use of grafting agents bearing a reactive end group and a long compatibilizing tail.

  9. Smart Surface Chemistries of Conducting Polymers

    DEFF Research Database (Denmark)

    Lind, Johan Ulrik

    In this thesis we investigate post-polymerization covalent modifications of poly(3,4-dioxythiophene (PEDOT)-type conducting polymers. The aim of the modifications is to gain specific control of the interaction between the material and living mammalian cells. The use of “click-chemistry” to modify...... a straightforward and in-expensive method for patterning conducting polymer thin films into microelectrodes, without losing control of the surface chemistry of the samples. On the contrary, the method provides direct control of the surface chemistry of both the fabricated micro-electrodes and the gaps between them....... The method is based on locally removing PEDOTtype polymers to expose underlying non-conducting functional polymer substrates. Thereby, multifunctional substrates are obtained. By applying this method, we are able to fabricate allpolymer micro-systems with multiple types of localized functional (bio...

  10. Determination of Concentration of Amphiphilic Polymer Molecules on the Surface of Encapsulated Semiconductor Nanocrystals.

    Science.gov (United States)

    Fedosyuk, Aleksandra; Radchanka, Aliaksandra; Antanovich, Artsiom; Prudnikau, Anatol; Kvach, Maksim V; Shmanai, Vadim; Artemyev, Mikhail

    2016-03-01

    We present a method for the determination of the average number of polymer molecules on the surface of A(II)B(VI) luminescent core-shell nanocrystals (CdSe/ZnS, ZnSe/ZnS quantum dots, and CdS/ZnS nanorods) encapsulated with amphiphilic polymer. Poly(maleic anhydride-alt-1-tetradecene) (PMAT) was quantitatively labeled with amino-derivative of fluorescein and the average amount of PMAT molecules per single nanocrystal was determined using optical absorption of the dye in the visible spectral range. The average amount of PMAT molecules grows linearly with the surface area of all studied nanocrystals. However, the surface density of the monomer units increases nonlinearly with the surface area, because of the increased competition between PMAT molecules for Zn-hexanethiol surface binding sites. The average value of zeta potential (ζ = -35 mV) was found to be independent of the size, shape, and chemical composition of nanocrystals at fixed buffer parameters (carbonate-bicarbonate buffer, pH 9.5 and 5 mM ionic strength). This finding is expected to be useful for the determination of the surface density of remaining carboxyl groups in PMAT-encapsulated nanocrystals. PMID:26866303

  11. Radiation-induced doping of conducting polymers

    International Nuclear Information System (INIS)

    Conducting polymers have the potential form many applications in electronics. The various patterns of doped regions of conducting polymers should be generated for the applications. Doping of conducting polymers is achieved by contact of the polymer with dopant or electrochemically. By these methods, doping occurs in the entire area exposed to the dopant. It is necessary to combine these doping techniques with lithography for achieving the patterned doping. Radiation-induced doping effects of conducting polymers have been reported. The doping is performed by irradiation of polymers in an atmosphere of gases, which do not react without irradiation, such as CH3Br, SF6, and N2O. If only the irradiated area was doped, patterned doping could be achieved without using lithography technique. We have elucidated the mechanism of the radiation-induced doping. The electrical conductivity was increased by irradiation the gas near the polymer film without irradiating the film itself. This result indicates that dopants were generated upon irradiation in the gas phase and the dopants react with the polymer. Hence, the pattern of doping is blurred by this method. We then developed another method of radiation-induced doping. Solid dopant precursor was coated on the polymer, and irradiation was performed. Figure 1 shows the results for poly(3-octylhitophene)(P3OT) by this method. A film of poly(3-octylthiophene) was prepared by spin coating from a solution of tetrahydrofuran on a quartz plate. The thickness of the film was approximately 100 nm. The polymer film was dried overnight at 80 degree C in a vacuum, and Au electrodes were evaporated on the films for electrical conductivity measurements. Saturated solution of 1,2,5,6,9,10-hexabromocyclododecane (HBCD) in 1-bromopropane was dropped on the film and dried at room temperature in a vacuum. The film was put in a vacuum chamber, which has a 0.2-mm-thick Be window. X rays entered through the Be window, and the films were irradiated

  12. Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer

    Science.gov (United States)

    Colvin, V. L.; Schlamp, M. C.; Alivisatos, A. P.

    1994-08-01

    ELECTROLUMINESCENT devices have been developed recently that are based on new materials such as porous silicon1 and semiconducting polymers2,3. By taking advantage of developments in the preparation and characterization of direct-gap semiconductor nanocrystals4-6, and of electroluminescent polymers7, we have now constructed a hybrid organic/inorganic electroluminescent device. Light emission arises from the recombination of holes injected into a layer of semiconducting p-paraphenylene vinylene (PPV)8-10 with electrons injected into a multilayer film of cadmium selenide nanocrystals. Close matching of the emitting layer of nanocrystals with the work function of the metal contact leads to an operating voltage11 of only 4V. At low voltages emission from the CdSe layer occurs. Because of the quantum size effect19-24 the colour of this emission can be varied from red to yellow by changing the nanocrystal size. At higher voltages green emission from the polymer layer predominates. Thus this device has a degree of voltage tunability of colour.

  13. Tactile Sensors Based on Conductive Polymers

    OpenAIRE

    Macicior, Haritz; Sikora, Tomasz; Ochoteco, Estíbalitz; Castellanos Ramos, Julián; Navas González, Rafael Jesús; Vidal Verdú, Fernando

    2010-01-01

    This paper presents results from a selection of tactile sensors that have been designed and fabricated. These sensors are based on a common approach that consists in placing a sheet of piezoresistive material on the top of a set of electrodes. We use a thin film of conductive polymer as the piezoresistive mate¬rial. Specifically, a conductive water-based ink of this polymer is deposited by spin coating on a flexible plastic sheet, giving it a smooth, homogeneous and conducting thin film. The ...

  14. Proton Conducting Polymer Electrolytes and Its Applications

    Institute of Scientific and Technical Information of China (English)

    S. Selvasekarapandian; G. Hirankumar; R. Baskaran; M.S. Bhuvaneswari

    2005-01-01

    @@ 1Introduction Proton conducting solid polymer electrolytes have been extensively studied due to their potential applications in electrochemical devices such as batteries, super capacitors, electrochromic windows, sensors etc[1,2]Many researchers have studied the behaviour of inorganic based polymer electrolytes as proton conductors and their applications in solid state devices at room temperature[3]. But, inorganic acid doped electrolytes have some serious disadvantages like corrosion towards the electrode and hazardous. Hence, there is need for searching new electrolyte which is stable towards the electrode. It has been reported that the ammonium salts which behaves like alkali metal salt are good dopant to the polymer matrix[4, 5] for the development of proton conducting polymer electrolyte. The proton conductors based on poly (ethylene oxide)[6], poly (ethylene succinate)[7], poly (ethylene glycol)[8], as host matrix doped with ammonium salt have already been reported.

  15. Thin functional conducting polymer films

    OpenAIRE

    Tian, S.

    2005-01-01

    In the present study, thin functional conducting polyaniline (PANI) films, either doped or undoped, patterned or unpatterned, were prepared by different approaches. The properties of the obtained PANI films were investigated in detail by a combination of electrochemistry with several other techniques, such as SPR, QCM, SPFS, diffraction, etc. The sensing applications (especially biosensing applications) of the prepared PANI films were explored. Firstly, the pure PANI films were prepar...

  16. Conducting polymers: Synthesis and industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Laboratory, NM (United States)

    1995-05-01

    The Conducting Polymer project funded by the AIM Materials Program is developing new methods for the synthesis of electronically conducting polymers and is evaluating new industrial applications for these materials which will result in significant reductions in energy usage or industrial waste. The applications specifically addressed during FY 1994 are electrochemical capacitors and membranes for gas separation. As an active material in electrochemical capacitors, conducting polymers have the potential of storing large amounts of electrical energy in low cost materials. Such devices are needed in electronics for power failure back-up and peak power, in power supplies for filtering, and in electric vehicles for peak power and load leveling. As a gas electrically adapt the membrane for specific gas combinations. Potential energy savings in the US. for this application are estimated at 1 to 3 quads/yr.

  17. Conducting polymers: Synthesis and industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1997-04-01

    The Conducting Polymer project funded by the AIM Program has developed new methods for the synthesis of conducting polymers and evaluated new industrial applications for these materials which will result in significant reductions in energy usage or industrial waste. The applications specifically addressed during FY 1996 included two ongoing efforts on membranes for gas separation and on electrochemical capacitors and a third new application: electrochemical reactors (ECRs) based on polymeric electrolytes. As a gas separation membrane, conducting polymers offer high selectivity and the potential to chemically or electrically adapt the membrane for specific gas combinations. Potential energy savings in the US for this application are estimated at 1 to 3 quads/yr. As an active material in electrochemical capacitors, electronically conducting polymers have the potential of storing large amounts of electric energy in low cost materials. Potential energy savings estimated at 1 quad/yr would result from introduction of electrochemical capacitors as energy storage devices in power trains of electric and hybrid vehicles, once such vehicles reach 20% of the total transportation market in the US. In the chlor-alkali industry, electrochemical reactors based on polymer electrolyte membranes consume around 1 % of the total electric power in the US. A new activity, started in FY 1996, is devoted to energy efficient ECRs. In the case of the chlor-alkali industry, energy savings as high as 50% seem possible with the novel ECR technology demonstrated by the author in 1996.

  18. Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Jordi Puiggalí

    2013-09-01

    Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  19. Interpenetrating networks of two conducting polymers

    DEFF Research Database (Denmark)

    Winther-Jensen, Bjørn; West, Keld

    2005-01-01

    Interpenetrating networks (IPNs) of two conjugated polymers are prepared by a combination of a chemical oxidation step and a vapour phase polymerisation step on non-conducting surfaces. In this work ferric tosylate was used as the oxidant as it gives very smooth and homogeneous coatings...

  20. Conductive Polymer Functionalization by Click Chemistry

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hvilsted, Søren; Hansen, Thomas Steen;

    2008-01-01

    Click chemistry is used to obtain new conductive polymer films based on poly(3,4-ethylenedioxythiophene) (PEDOT) from a new azide functional monomer. Postpolymerization, 1,3-dipolar cycloadditions in DMF, using a catalyst system of CUS04 and sodium ascorbate, and different alkynes are performed...

  1. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2015-07-21

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  2. Strategies for interfacing inorganic nanocrystals with biological systems based on polymer-coating.

    Science.gov (United States)

    Palui, Goutam; Aldeek, Fadi; Wang, Wentao; Mattoussi, Hedi

    2015-01-01

    Interfacing inorganic nanoparticles and biological systems with the aim of developing novel imaging and sensing platforms has generated great interest and much activity. However, the effectiveness of this approach hinges on the ability of the surface ligands to promote water-dispersion of the nanoparticles with long term colloidal stability in buffer media. These surface ligands protect the nanostructures from the harsh biological environment, while allowing coupling to target molecules, which can be biological in nature (e.g., proteins and peptides) or exhibit specific photo-physical characteristics (e.g., a dye or a redox-active molecule). Amphiphilic block polymers have provided researchers with versatile molecular platforms with tunable size, composition and chemical properties. Hence, several groups have developed a wide range of polymers as ligands or micelle capsules to promote the transfer of a variety of inorganic nanomaterials to buffer media (including magnetic nanoparticles and semiconductor nanocrystals) and render them biocompatible. In this review, we first summarize the established synthetic routes to grow high quality nanocrystals of semiconductors, metals and metal oxides. We then provide a critical evaluation of the recent developments in the design, optimization and use of various amphiphilic copolymers to surface functionalize the above nanocrystals, along with the strategies used to conjugate them to target biomolecules. We finally conclude by providing a summary of the most promising applications of these polymer-coated inorganic platforms in sensor design, and imaging of cells and tissues.

  3. Intrinsically conductive polymer thin film piezoresistors

    DEFF Research Database (Denmark)

    Lillemose, Michael; Spieser, Martin; Christiansen, N.O.;

    2008-01-01

    We report on the piezoresistive effect in the intrinsically conductive polymer, polyaniline. A process recipe for indirect patterning of thin film polyaniline has been developed. Using a specially designed chip, the polyaniline thin films have been characterised with respect to resistivity...... and strain sensitivity using two- and four-point measurement method. We have found that polyaniline has a negative gauge factor of K = -4.9, which makes it a candidate for piezoresistive read-out in polymer based MEMS-devices. (C) 2007 Elsevier B.V. All rights reserved....

  4. Ion-Conducting Organic/Inorganic Polymers

    Science.gov (United States)

    Kinder, James D.; Meador, Mary Ann B.

    2007-01-01

    Ion-conducting polymers that are hybrids of organic and inorganic moieties and that are suitable for forming into solid-electrolyte membranes have been invented in an effort to improve upon the polymeric materials that have been used previously for such membranes. Examples of the prior materials include perfluorosulfonic acid-based formulations, polybenzimidazoles, sulfonated polyetherketone, sulfonated naphthalenic polyimides, and polyethylene oxide (PEO)-based formulations. Relative to the prior materials, the polymers of the present invention offer greater dimensional stability, greater ease of formation into mechanically resilient films, and acceptably high ionic conductivities over wider temperature ranges. Devices in which films made of these ion-conducting organic/inorganic polymers could be used include fuel cells, lithium batteries, chemical sensors, electrochemical capacitors, electrochromic windows and display devices, and analog memory devices. The synthesis of a polymer of this type (see Figure 1) starts with a reaction between an epoxide-functionalized alkoxysilane and a diamine. The product of this reaction is polymerized by hydrolysis and condensation of the alkoxysilane group, producing a molecular network that contains both organic and inorganic (silica) links. The silica in the network contributes to the ionic conductivity and to the desired thermal and mechanical properties. Examples of other diamines that have been used in the reaction sequence of Figure 1 are shown in Figure 2. One can use any of these diamines or any combination of them in proportions chosen to impart desired properties to the finished product. Alternatively or in addition, one could similarly vary the functionality of the alkoxysilane to obtain desired properties. The variety of available alkoxysilanes and diamines thus affords flexibility to optimize the organic/inorganic polymer for a given application.

  5. Structure and Conductivity of Semiconducting Polymer Hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Rachel C.; Ferreira, Amy S.; Aguirre, Jordan C.; Kilbride, Daniel; Toso, Daniel B.; Mayoral, Kenny; Zhou, Z. Hong; Kopidakis, Nikos; Rubin, Yves; Schwartz, Benjamin J.; Mason, Thomas G.; Tolbert, Sarah H.

    2016-07-07

    Poly(fluorene-alt-thiophene) (PFT) is a conjugated polyelectrolyte that self-assembles into rod-like micelles in water, with the conjugated polymer backbone running along the length of the micelle. At modest concentrations (-10 mg/mL in aqueous solutions), PFT forms hydrogels, and this work focuses on understanding the structure and intermolecular interactions in those gel networks. The network structure can be directly visualized using cryo electron microscopy. Oscillatory rheology studies further tell us about connectivity within the gel network, and the data are consistent with a picture where polymer chains bridge between micelles to hold the network together. Addition of tetrahydrofuran (THF) to the gels breaks those connections, but once the THF is removed, the gel becomes stronger than it was before, presumably due to the creation of a more interconnected nanoscale architecture. Small polymer oligomers can also passivate the bridging polymer chains, breaking connections between micelles and dramatically weakening the hydrogel network. Fits to solution-phase small-angle X-ray scattering data using a Dammin bead model support the hypothesis of a bridging connection between PFT micelles, even in dilute aqueous solutions. Finally, time-resolved microwave conductivity measurements on dried samples show an increase in carrier mobility after THF annealing of the PFT gel, likely due to increased connectivity within the polymer network.

  6. Thermal conductivity and multiferroics of electroactive polymers and polymer composites

    Science.gov (United States)

    Jin, Jiezhu

    Electronically conducting polymers and electromechanical polymers are the two important branches of the cutting-edge electroactive polymers. They have shown significant impact on many modern technologies such as flat panel display, energy transport, energy conversion, sensors and actuators. To utilize conducting polymers in microelectronics, optoelectronics and thermoelectrics, it is necessary to have a comprehensive study of their thermal conductivity since thermal conductivity is a fundamental materials property that is particularly important and sometimes a determining factor of the device performance. For electromechanical polymers, larger piezoelectric effect will contribute to the improvement of magnetoelectric (ME) coupling efficiency in their multiferroic composites. This dissertation is devoted to characterizing electronically conducting polymers for their electrical and thermal conductivity, and developing new classes of electromechanical polymers and strain-mediated electromechanical polymer-based multiferroic ME composites. Conducting polymers opened up new possibilities for devices combining novel electrical and thermal properties, but there has been limited understanding of the length-scale effect of the electrical and thermal conductivity, and the mechanism underlying the electricity and heat transport behavior. In this dissertation, the analytical model and experimental technique are presented to measure the in-plane thermal conductivity of polyaniline thin films. For camphorsulfonic acid doped polyaniline patterned on silicon oxide/silicon substrate using photolithography and reactive ion etching, the thermal conductivity of the film with thickness of 20 nm is measured to be 0.0406 W/m˙K, which significantly deviates from their bulk (> 0.26 W/m˙K). The size effect on thermal conductivity at this scale is attributed to the significant phonon boundary scattering. When the film goes up to 130 nm thick, the thermal conductivity increases to 0.166 W

  7. Ion conducting organic/inorganic hybrid polymers

    Science.gov (United States)

    Meador, Maryann B. (Inventor); Kinder, James D. (Inventor)

    2010-01-01

    This invention relates to a series of organic/inorganic hybrid polymers that are easy to fabricate into dimensionally stable films with good ion-conductivity over a wide range of temperatures for use in a variety of applications. The polymers are prepared by the reaction of amines, preferably diamines and mixtures thereof with monoamines with epoxy-functionalized alkoxysilanes. The products of the reaction are polymerized by hydrolysis of the alkoxysilane groups to produce an organic-containing silica network. Suitable functionality introduced into the amine and alkoxysilane groups produce solid polymeric membranes which conduct ions for use in fuel cells, high-performance solid state batteries, chemical sensors, electrochemical capacitors, electro-chromic windows or displays, analog memory devices and the like.

  8. Functional composite coatings containing conducting polymers

    OpenAIRE

    Jafarzadeh, Shadi

    2014-01-01

    Organic coatings are widely used to lower the corrosion rate of metallic structures. However, penetration of water, oxygen and corrosive ions through pores present in the coating results in corrosion initiation and propagation once these species reach the metal substrate. Considering the need for systems that offer active protection with self-healing functionality, composite coatings containing polyaniline (PANI) conducting polymer are proposed in this study. In the first phase of my work, PA...

  9. Electrochromic window with lithium conductive polymer electrolyte

    OpenAIRE

    Baudry, Paul; Aegerter, Michel A.; Deroo, Daniel; Valla, Bruno

    1991-01-01

    An electrochromic window was built using WO3 as the electrochromic material and V2O5 as the counter-electrode. Both were deposited onto ITO coated glass panes by vacuum evaporation and were amorphous to X-ray diffraction. The electrolyte was a lithium conducting polymer constituted by a Poly (ethylene oxide) - lithium salt complex. The electrochemical characterization of electrodes was realized by cyclic voltammetry, coulometric titration, and impedance spectroscopy, which allowd the determin...

  10. Formulation of anticorrosive paints employing conducting polymers

    OpenAIRE

    Martí Barroso, Mireia

    2013-01-01

    The intention and purpose of the present thesis is to prepare a series of protective coatings using some conducting polymers (CPs) as corrosion inhibitors. The use of organic paints is the most common method for corrosion prevention. Anticorrosive coatings form a class of high-performance systems with a very wide range of applications and being classified in two broad groups: heavy-duty coatings, for high performance, and light-duty coatings, for medium performance. The first class being requ...

  11. The Organic Chemistry of Conducting Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Tolbert, Laren Malcolm [Georgia Inst. of Technology, Atlanta, GA (United States)

    2014-12-01

    For the last several years, we have examined the fundamental principles of conduction in one-dimensional systems, i.e., molecular “wires”. It is, of course, widely recognized that such systems, as components of electronically conductive materials, function in a two- and three-dimensional milieu. Thus interchain hopping and grain-boundary resistivity are limiting conductivity factors in highly conductive materials, and overall conductivity is a function of through-chain and boundary hopping. We have given considerable attention to the basic principles underlying charge transport (the “rules of the game”) in two-dimensional systems by using model systems which allow direct observation of such processes, including the examination of tunneling and hopping as components of charge transfer. In related work, we have spent considerable effort on the chemistry of conjugated heteropolymers, most especially polythiophens, with the aim of using these most efficient of readily available electroactive polymers in photovoltaic devices.

  12. Bulk limited conduction in electroluminescent polymer devices

    Science.gov (United States)

    Campbell, A. J.; Weaver, M. S.; Lidzey, D. G.; Bradley, D. D. C.

    1998-12-01

    The current-voltage (J-V) characteristics of ITO/polymer film/Al or Au structures of poly(phenylene vinylene) (PPV) and a dialkoxy PPV copolymer have been recorded for a range of different film thickness d and temperatures T. At high applied bias all the characteristics can be fitted over a given range to a power law J=KVm, where m increases with decreasing T, log(K) is proportional to m, and K is proportional to d-α m, where α˜2 (ITO/polymer film/Al devices) and ˜1 (ITO/polymer film/Au devices). Different single carrier space charge limited conduction theories have been used to try and explain this behavior. The analytical theory in which the carrier density is decreased by an exponential trap distribution lying below effectively isoelectronic transport states is in good agreement, but cannot explain the thickness dependence of the ITO/polymer film/Au devices and can be criticized as being physically unreasonable. A numerical analysis in which the mobility has the field and temperature dependence found for hopping transport in disordered systems is also in good agreement, but can only fit a small range of J and cannot explain the magnitude of K, the temperature dependence of m or the abrupt change in slope in the J-V characteristics with increasing bias. Mixed models are equally good but cannot explain the deviations from experiment. We consider that further experimental studies of carrier mobilities and the nature of the traps present in such materials is required to distinguish between these models and resolve the nature of bulk limited conduction in conjugated polymers.

  13. Tactile sensors based on conductive polymers

    Science.gov (United States)

    Castellanos-Ramos, Julian; Navas-Gonzalez, Rafael; Macicior, Haritz; Ochoteco, Estibalitz; Vidal-Verdú, Fernando

    2009-05-01

    This paper presents results from a few tactile sensors we have designed and fabricated. These sensors are based on a common approach that consists of placing a sheet of piezoresistive material on the top of a set of electrodes. If a force is exerted against the surface of the so obtained sensor, the contact area between the electrodes and the piezoresistive material changes. Therefore, the resistance at the interface changes. This is exploited as transconduction principle to measure forces and build advanced tactile sensors. For this purpose, we use a thin film of conductive polymers as the piezoresistive material. Specifically, a conductive water-based ink of these polymers is deposited by spin coating on a flexible plastic sheet, giving as a result a smooth, homogeneous and conducting thin film on it. The main interest in this procedure is it is cheap and it allows the fabrication of flexible and low cost tactile sensors. In this work we present results from sensors made with two technologies. First, we have used a Printed Circuit Board technology to fabricate the set of electrodes and addressing tracks. Then we have placed the flexible plastic sheet with the conductive polymer film on them to obtain the sensor. The result is a simple, flexible tactile sensor. In addition to these sensors on PCB, we have proposed, designed and fabricated sensors with a screen printing technology. In this case, the set of electrodes and addressing tracks are made by printing an ink based on silver nanoparticles. There is a very interesting difference with the other sensors, that consists of the use of an elastomer as insulation material between conductive layers. Besides of its role as insulator, this elastomer allows the modification of the force versus resistance relationship. It also improves the dynamic response of the sensor because it implements a restoration force that helps the sensor to relax quicker when the force is taken off.

  14. Electrochemical Analysis of Conducting Polymer Thin Films

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2010-04-01

    Full Text Available Polyelectrolyte multilayers built via the layer-by-layer (LbL method has been one of the most promising systems in the field of materials science. Layered structures can be constructed by the adsorption of various polyelectrolyte species onto the surface of a solid or liquid material by means of electrostatic interaction. The thickness of the adsorbed layers can be tuned precisely in the nanometer range. Stable, semiconducting thin films are interesting research subjects. We use a conducting polymer, poly(p-phenylene vinylene (PPV, in the preparation of a stable thin film via the LbL method. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to characterize the ionic conductivity of the PPV multilayer films. The ionic conductivity of the films has been found to be dependent on the polymerization temperature. The film conductivity can be fitted to a modified Randle’s circuit. The circuit equivalent calculations are performed to provide the diffusion coefficient values.

  15. Patterned structures of in situ size controlled CdS nanocrystals in a polymer matrix under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fragouli, D; Pompa, P P; Caputo, G; Cingolani, R; Athanassiou, A [NNL-National Nanotechnology Laboratory, INFM, CNR, Via Arnesano, 73100 Lecce (Italy); Resta, V; Laera, A M; Tapfer, L [ENEA, Centro Ricerche Brindisi, SS7 Appia Km 706, I-72100 Brindisi (Italy)], E-mail: despina.fragouli@unile.it

    2009-04-15

    A method of in situ formation of patterns of size controlled CdS nanocrystals in a polymer matrix by pulsed UV irradiation is presented. The films consist of Cd thiolate precursors with different carbon chain lengths embedded in TOPAS polymer matrices. Under UV irradiation the precursors are photolyzed, driving to the formation of CdS nanocrystals in the quantum size regime, with size and concentration defined by the number of incident UV pulses, while the host polymer remains macroscopically/microscopically unaffected. The emission of the formed nanocomposite materials strongly depends on the dimensions of the CdS nanocrystals, thus, their growth at the different phases of the irradiation is monitored using spatially resolved photoluminescence by means of a confocal microscope. X-ray diffraction measurements verified the existence of the CdS nanocrystals, and defined their crystal structure for all the studied cases. The results are reinforced by transmission electron microscopy. It is proved that the selection of the precursor determines the efficiency of the procedure, and the quality of the formed nanocrystals. Moreover it is demonstrated that there is the possibility of laser induced formation of well-defined patterns of CdS nanocrystals, opening up new perspectives in the development of nanodevices.

  16. Electrochemical relaxation at electrically conducting polymers

    Science.gov (United States)

    Nateghi, M. R.; zarandi, M. B.

    2008-08-01

    In this study, slow relaxation (SR) associated with the electroreduction of polyaniline (PAn) films during polarization to high cathodic potentials was investigated by cyclic voltammetry technique. Anodic voltammetric currents were used as experimental variable to indicate the relaxation occurring in PAn films deposited electrochemically on the Pt electrode surface. The dependence of SR on polymer film thickness, waiting potential, and mobility of the doped anion was investigated. Percolation threshold potential for heteropolyanion doped PAn was estimated to be between 150 and 200 mV depending on polymer thickness on the electrode surface. A new model of the conducting to insulating conversion is described by the percolation theory and mobility gap changes during the process.

  17. Electrochemical relaxation at electrically conducting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Nateghi, M R [Department of Chemistry, Islamic Azad University, Yazd-Branch, Yazd (Iran, Islamic Republic of); Zarandi, M B [Department of physics, Yazd University, Yazd (Iran, Islamic Republic of)

    2008-08-15

    In this study, slow relaxation (SR) associated with the electroreduction of polyaniline (PAn) films during polarization to high cathodic potentials was investigated by cyclic voltammetry technique. Anodic voltammetric currents were used as experimental variable to indicate the relaxation occurring in PAn films deposited electrochemically on the Pt electrode surface. The dependence of SR on polymer film thickness, waiting potential, and mobility of the doped anion was investigated. Percolation threshold potential for heteropolyanion doped PAn was estimated to be between 150 and 200 mV depending on polymer thickness on the electrode surface. A new model of the conducting to insulating conversion is described by the percolation theory and mobility gap changes during the process.

  18. Enhanced ethylene separation and plasticization resistance in polymer membranes incorporating metal-organic framework nanocrystals

    Science.gov (United States)

    Bachman, Jonathan E.; Smith, Zachary P.; Li, Tao; Xu, Ting; Long, Jeffrey R.

    2016-08-01

    The implementation of membrane-based separations in the petrochemical industry has the potential to reduce energy consumption significantly relative to conventional separation processes. Achieving this goal, however, requires the development of new membrane materials with greater selectivity, permeability and stability than available at present. Here, we report composite materials consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide, which can exhibit enhanced selectivity for ethylene over ethane, greater ethylene permeability and improved membrane stability. Our results suggest that framework-polymer interactions reduce chain mobility of the polymer while simultaneously boosting membrane separation performance. The increased stability, or plasticization resistance, is expected to improve membrane utility under real process conditions for petrochemical separations and natural gas purification. Furthermore, this approach can be broadly applied to numerous polymers that encounter aggressive environments, potentially making gas separations possible that were previously inaccessible to membranes.

  19. Enhanced ethylene separation and plasticization resistance in polymer membranes incorporating metal-organic framework nanocrystals.

    Science.gov (United States)

    Bachman, Jonathan E; Smith, Zachary P; Li, Tao; Xu, Ting; Long, Jeffrey R

    2016-08-01

    The implementation of membrane-based separations in the petrochemical industry has the potential to reduce energy consumption significantly relative to conventional separation processes. Achieving this goal, however, requires the development of new membrane materials with greater selectivity, permeability and stability than available at present. Here, we report composite materials consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide, which can exhibit enhanced selectivity for ethylene over ethane, greater ethylene permeability and improved membrane stability. Our results suggest that framework-polymer interactions reduce chain mobility of the polymer while simultaneously boosting membrane separation performance. The increased stability, or plasticization resistance, is expected to improve membrane utility under real process conditions for petrochemical separations and natural gas purification. Furthermore, this approach can be broadly applied to numerous polymers that encounter aggressive environments, potentially making gas separations possible that were previously inaccessible to membranes.

  20. Spatially Selective Functionalization of Conducting Polymers by "Electroclick" Chemistry

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Daugaard, Anders Egede; Hvilsted, Søren;

    2009-01-01

    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...

  1. Tailoring percolating conductive networks of natural rubber composites for flexible strain sensors via a cellulose nanocrystal templated assembly.

    Science.gov (United States)

    Wang, Shuman; Zhang, Xinxing; Wu, Xiaodong; Lu, Canhui

    2016-01-21

    Conductive polymer composites (CPCs) just above the percolation threshold exhibit a unique strain-reversible electric response upon application of tensile strain, which can be used to prepare strain sensors. However, it is difficult to balance the electric conductivity which is fundamental to a stable output signal and the strain sensing sensitivity due to the relatively dense conductive pathways of the traditional CPCs. Constructing a "brittle" but effective conductive network structure in CPCs is the essential foundation of a desirable sensing material. Here, we demonstrate for the first time that highly flexible, stretchable, sensitive, and reversible strain sensors can be fabricated by a facile latex assembly approach, in which nontoxic, sustainable and biodegradable cellulose nanocrystals played a key role in tailoring the percolating network of conductive natural rubber (NR)/carbon nanotube (CNT) composites. The resulting nanocomposites with a continuous 3D conductive structure exhibited a very low electrical conductivity percolation threshold (4-fold lower than that of the conventional NR/CNT composites), high resistivity and sensitivity (gauge factor ≈ 43.5) and meanwhile good reproducibility of up to 100% strain. The proposed materials and principles in this study open up a novel practical approach to design high performance flexible sensors for a broad range of multifunctional applications. PMID:26542376

  2. Electrochemical characterization of aminated acrylic conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  3. Biomimetic electrochemistry from conducting polymers. A review

    International Nuclear Information System (INIS)

    Highlights: ► Composition and properties of conducting polymers change during reactions. ► These properties are being exploited to develop biomimetic reactive and soft devices. ► The state of the art for artificial muscles sensing working conditions was reviewed. ► Smart membranes, drug delivery devices and nervous interfaces were also reviewed. - Abstract: Films of conducting polymers in the presence of electrolytes can be oxidized or reduced by the flow of anodic or cathodic currents. Ions and solvent are exchanged during a reaction for charge and osmotic pressure balance. A reactive conducting polymer contains ions and solvent. Such variation of composition during a reaction is reminiscent of the biological processes in cells. Along changes to the composition of the material during a reaction, there are also changes to other properties, including: volume (electrochemomechanical), colour (electrochromic), stored charge (electrical storage), porosity or permselectivity (electroporosity), stored chemicals, wettability and so on. Most of those properties mimic similar property changes in organs during their functioning. These properties are being exploited to develop biomimetic reactive and soft devices: artificial muscles and polymeric actuators; supercapacitors and all organic batteries; smart membranes; electron-ion transducers; nervous interfaces and artificial synapses, or drug delivery devices. In this review we focus on the state of the art for artificial muscles, smart membranes and electron-ion transducers. The reactive nature of those devices provide them with a unique advantage related to the present days technologies: any changes in the surrounding physical or chemical variable acting on the electrochemical reaction rate will be sensed by the device while working. Working under constant current (driving signal), the evolution of the device potential or the evolution of the consumed electrical energy (sensing signals) senses and quantifies the

  4. Polymer composite material structures comprising carbon based conductive loads

    OpenAIRE

    Jérôme, Robert; Pagnoulle, Christophe; Detrembleur, Christophe; Thomassin, Jean-Michel; Huynen, Isabelle; Bailly, Christian; Bednarz, Luikasz; Daussin, Raphaël; Saib, Aimad; Baudouin, Anne-Christine; Laloyaux, Xavier

    2007-01-01

    The present invention provides a polymer composite material structure comprising at least one layer of a foamed polymer composite material comprising a foamed polymer matrix and 0.1 wt % to 6 wt % carbon based conductive loads, such as e.g. carbon nanotubes, dispersed in the foamed polymer matrix. The polymer composite material structure according to embodiments of the present invention shows good shielding and absorbing properties notwithstanding the low amount of carbon based conductive loa...

  5. Polymer composite material structures comprising carbon based conductive loads

    OpenAIRE

    Jérôme, Robert; Pagnoulle, Christophe; Detrembleur, Christophe; Thomassin, Jean-Michel; Huynen, Isabelle; Bailly, Christian; Bednarz, Lucasz; Daussin, Raphaël; Saib, Aimad

    2006-01-01

    The present invention provides a polymer composite material structure comprising at least one layer of a foamed polymer composite material comprising a foamed polymer matrix and 0.1 to 6 wt% carbon based conductive loads, such as e.g. carbon nanotubes, dispersed in the foamed polymer matrix. The polymer composite material structure according to embodiments of the present invention shows good shielding and absorbing properties notwithstanding the low amount of carbon based conductive loads. Th...

  6. Integration of conducting polymer network in non-conductive polymer substrates

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; West, Keld; Hassager, Ole;

    2006-01-01

    absorption during sequential reactive ion etching has allowed for analysis of the PEDOT distribution within the surface layer of thePMMA substrate. The surface resistance ofthe conducting polymer layer remains low while the surface layer at the same time adapts some of the mechanical properties...

  7. Silica nanocapsules of fluorescent conjugated polymers and superparamagnetic nanocrystals for dual-mode cellular imaging.

    Science.gov (United States)

    Tan, Happy; Wang, Miao; Yang, Chang-Tong; Pant, Shilpa; Bhakoo, Kishore Kumar; Wong, Siew Yee; Chen, Zhi-Kuan; Li, Xu; Wang, John

    2011-06-01

    We describe here a facile and benign synthetic strategy to integrate the fluorescent behavior of conjugated polymers and superparamagnetic properties of iron oxide nanocrystals into silica nanocapsules, forming a new type of bifunctional magnetic fluorescent silica nanocapsule (BMFSN). The resultant BMFSNs are uniform, colloidally stable in aqueous medium, and exhibit the desired dual functionality of fluorescence and superparamagnetism in a single entity. Four conjugated polymers with different emissions were used to demonstrate the versatility of employing this class of fluorescent materials for the preparation of BMFSNs. The applicability of BMFSNs in cellular imaging was studied by incubating them with human liver cancer cells, the result of which demonstrated that the cells could be visualized by dual-mode fluorescence and magnetic resonance imaging. Furthermore, the superparamagnetic behavior of the BMFSNs was exploited for in vitro magnetic-guided delivery of the nanocapsules into the cancer cells, thereby highlighting their potential for targeting biomedical applications.

  8. The relationship between nanoscale architecture and charge transport in conjugated nanocrystals bridged by multichromophoric Polymers.

    Science.gov (United States)

    Dabirian, Reza; Palermo, Vincenzo; Liscio, Andrea; Schwartz, Erik; Otten, Matthijs B J; Finlayson, Chris E; Treossi, Emanuele; Friend, Richard H; Calestani, Gianluca; Müllen, Klaus; Nolte, Roeland J M; Rowan, Alan E; Samorì, Paolo

    2009-05-27

    We report on the self-assembly and the electrical characterization of bicomponent films consisting of an organic semiconducting small molecule blended with a rigid polymeric scaffold functionalized in the side chains with monomeric units of the same molecule. The molecule and polymer are a perylene-bis(dicarboximide) monomer (M-PDI) and a perylene-bis(dicarboximide)-functionalized poly(isocyanopeptide) (P-PDI), which have been codeposited on SiO(x) and mica substrates from solution. These bicomponent films have been characterized by atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM), revealing the relationship between architecture and function for various supramolecular nanocrystalline arrangements at a nanometer spatial resolution. Monomer-polymer interactions can be controlled by varying solvent and/or substrate polarity, so that either the monomer packing dictates the polymer morphology or vice versa, leading to a morphology exhibiting M-PDI nanocrystals connected with each other by P-PDI polymer wires. Compared to pure M-PDI or P-PDI films, those bicomponent films that possess polymer interconnections between crystallites of the monomer display a significant improvement in electrical connectivity and a 2 orders of magnitude increase in charge carrier mobility within the film, as measured in thin film transistor (TFT) devices. Of a more fundamental interest, our technique allows the bridging of semiconducting crystals, without the formation of injection barriers at the connection points.

  9. Photogeneration of polaron pairs in conducting polymers

    Science.gov (United States)

    Conwell, E. M.; Mizes, H. A.

    1995-03-01

    It is usually assumed that when photogeneration in a conducting polymer results in an electron and hole on separate chains they form negative and positive polarons that can move independently of each other. We show, on the basis of the small carrier yield per photon seen in picosecond photoconductivity, the different behavior of photoinduced absorption (PA) in dilute solution and thin films, and the spectral distribution of the PA in thin films, that photogenerated positive and negative polarons in poly(p-phenylene vinylene), polythiophene, and polyacetylene are, for the most part, bound in pairs by their Coulomb attraction. We also show that PA data give evidence for a gap of 2.8 eV, and thus an exciton binding energy of 0.4 eV, in poly(p-phenylene vinylene).

  10. Mechanisms of proton conductance in polymer electrolyte membranes

    DEFF Research Database (Denmark)

    Eikerling, M.; Kornyshev, A. A.; Kuznetsov, A. M.;

    2001-01-01

    We provide a phenomenological description of proton conductance in polymer electrolyte membranes, based on contemporary views of proton transfer processes in condensed media and a model for heterogeneous polymer electrolyte membrane structure. The description combines the proton transfer events i...

  11. Transparent and conductive polymer layers by gas plasma techniques

    OpenAIRE

    Groenewoud, Lucas Marinus Hendrikus

    2000-01-01

    Polymers are widely used in a great number of applications because of their general properties such as low density, low cost, and processability. If these properties could be combined with electrical conductivity, this would open up the way to desirable applications such as flexible LCD’s and polymer electronics (cheap, lightweight, etc.). For applications requiring electrical conductivity, the choice of a suitable polymer is limited to polymers with a conjugated chemical structure such as po...

  12. DNA-sensors based on functionalized conducting polymers and quantum dots

    Science.gov (United States)

    Kjällman, Tanja; Peng, Hui; Travas-Sejdic, Jadranka; Soeller, Christian

    2007-12-01

    The availability of rapid and specific biosensors is of great importance for many areas of biomedical research and modern biotechnology. This includes a need for DNA sensors where the progress of molecular biology demands routine detection of minute concentrations of specific gene fragments. A promising alternative approach to traditional DNA essays utilizes novel smart materials, including conducting polymers and nanostructured materials such as quantum dots. We have constructed a number of DNA sensors based on smart materials that allow rapid one-step detection of unlabeled DNA fragments with high specificity. These sensors are based on functionalized conducting polymers derived from polypyrrole (PPy) and poly(p-phenylenevinylene) (PPV). PPy based sensors provide intrinsic electrical readout via cyclic voltammetry and electrochemical impedance spectroscopy. The performance of these sensors is compared to a novel self-assembled monolayer-PNA construct on a gold electrode. Characterization of the novel PNA based sensor shows that it has comparable performance to the PPy based sensors and can also be read out effectively using AC cyclic voltammetry. Complementary to such solid substrate sensors we have developed a novel optical DNA essay based on a new PPV derived cationic conducting polymer. DNA detection in this essay results from sample dependent fluorescence resonance energy transfer changes between the cationic conducting polymer and Cy3 labeled probe oligonucleotides. As an alternative to such fluorochrome based sensors we discuss the use of inorganic nanocrystals ('quantum dots') and present data from water soluble CdTe quantum dots synthesized in an aqueous environment.

  13. Conducting polymers as potential active materials in electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Rudge, A.; Davey, J.; Raistrick, I.; Gottesfeld, S. [Los Alamos National Lab., NM (United States); Ferraris, J.P. [Texas Univ., Richardson, TX (United States). Dept. of Chemistry

    1992-12-01

    Electronically,conducting polymers represent an interesting class of materials for use in electrochemical capacitors because of the combination of high capacitive energy density and low materials cost. Three generalized types of electrochemical capacitors can be constructed using conducting polymers as active material, and in the third of these, which utilizes conducting polymers that can be both n- and p-doped, energy densities of up to 40 watt-hours per kilogram of active material on both electrodes have been demonstrated.

  14. Conducting polymers as potential active materials in electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Rudge, A.; Davey, J.; Raistrick, I.; Gottesfeld, S. (Los Alamos National Lab., NM (United States)); Ferraris, J.P. (Texas Univ., Richardson, TX (United States). Dept. of Chemistry)

    1992-01-01

    Electronically,conducting polymers represent an interesting class of materials for use in electrochemical capacitors because of the combination of high capacitive energy density and low materials cost. Three generalized types of electrochemical capacitors can be constructed using conducting polymers as active material, and in the third of these, which utilizes conducting polymers that can be both n- and p-doped, energy densities of up to 40 watt-hours per kilogram of active material on both electrodes have been demonstrated.

  15. Analytical device for test fluids, comprises a conductive polymer composition

    OpenAIRE

    Hands, Philip J.W.; Bloor, David; Laughlin, Paul J.; Lussey, David

    2002-01-01

    A sensor for chemical species or biological species or radiation presenting to test fluid a polymer composition comprises polymer and conductive filler metal, alloy or reduced metal oxide and having a first level of electrical conductance when quiescent and being convertible to a second level of conductance by change of stress applied by stretching or compression or electric field, in which the polymer composition is characterised by at least one of the features in the form of particles at le...

  16. Progress in using conductive polymers as corrosion-inhibiting coatings

    International Nuclear Information System (INIS)

    A general review of the chemistry and corrosion control properties of electroactive polymers will be presented. These polymers are also known as conductive polymers (CPs), and this term will be used throughout this article. This paper will focus on both the synthesis of applicable CPs used for corrosion protection in various environments and their potential benefits over common organic barrier coatings

  17. Conduction and trapping in electroluminescent polymer devices

    Science.gov (United States)

    Campbell, Alasdair J.; Weaver, Michael S.; Lidzey, David G.; Bradley, Donal D. C.; Werner, Ekkehard; Bruetting, Wolfgang; Schwoerer, Markus

    1998-12-01

    The current-voltage characteristics of ITO/polymer film/Al or Au devices of poly(phenylene vinylene) (PPV) and a dialkoxy PPV copolymer can be fitted at high applied bias to a power law of the form J equals KVm where m increases with decreasing temperature, log(K) is proportional to m, and K is proportional to d-(alpha m) where d is the film thickness and (alpha) is a constant. (alpha) 2 and 1 for the Al and Au cathode devices respectively. Different single carrier space charge limited conduction (SCLC) theories, including either an exponential trap distribution or a hopping transport field and temperature dependent mobility, are used to try and explain this behavior. Both models are in good agreement with the general experimental results, but can also be criticized on a number of specific issues.Mixed SCLC models and the effect of dispersive transport are also explored. It is concluded that carrier mobility and trap measurements are required to distinguish between these models. To this end, initial trap measurements of ITO/PPV/Al devices using deep level transient spectroscopy (DLTS) are reported. Very deep positive carrier transport with emptying times > 4 minutes have been detected. The non-exponential DLTS transients have been successfully modeled on an isoelectronic trap level emptying to a Gaussian distribution of transport states, with a trap depth and density of 0.8eV and 4 by 1016 cm-3 respectively.

  18. Electrochemical Impedance Spectroscopy of Conductive Polymer Coatings

    Science.gov (United States)

    Calle, Luz Marina; MacDowell, Louis G.

    1996-01-01

    Electrochemical impedance spectroscopy (EIS) was used to investigate the corrosion protection performance of twenty nine proprietary conductive polymer coatings for cold rolled steel under immersion in 3.55 percent NaCl. Corrosion potential as well as Bode plots of the data were obtained for each coating after one hour immersion, All coatings, with the exception of one, have a corrosion potential that is higher in the positive direction than the corrosion potential of bare steel under the same conditions. Group A consisted of twenty one coatings with Bode plots indicative of the capacitive behavior characteristic of barrier coatings. An equivalent circuit consisting of a capacitor in series with a resistor simulated the experimental EIS data for these coatings very well. Group B consisted of eight coatings that exhibited EIS spectra showing an inflection point which indicates that two time constants are present. This may be caused by an electrochemical process taking place which could be indicitive of coating failing. These coatings have a lower impedance that those in Group A.

  19. Polymer and Mesoporous Silica Microspheres with Chiral Nematic Order from Cellulose Nanocrystals.

    Science.gov (United States)

    Wang, Pei-Xi; Hamad, Wadood Y; MacLachlan, Mark J

    2016-09-26

    Polymer microspheres with chiral nematic order were obtained from an emulsion polymerization technique using cellulose nanocrystals (CNCs) as the template. The growth of the liquid crystals from tiny tactoids to droplets with spherical symmetry was captured and investigated by both optical and electron microscopy for the first time. The size of the microspheres could be tuned between tens and hundreds of micrometers; to obtain single, integrated chiral nematic kernels, the size of water droplets in the emulsion should be similar to that of CNC tactoids. Through a double-matrix templating method, novel silica microspheres with chiral nematic order were fabricated, which showed a high surface area and mesoporosity. The methods developed here may help to reveal the evolution of other self-assembling systems, and these materials have potential applications in optical devices and chiral separations. PMID:27581056

  20. Exciton Dynamics in Alternative Solar Cell Materials: Polymers, Nanocrystals, and Small Molecules

    Science.gov (United States)

    Pundsack, Thomas J.

    To keep fossil fuel usage in 2040 even with 2010 usage, 50% of global energy will need to come from alternative sources such as solar cells. While the photovoltaic market is currently dominated by crystalline silicon, there are many low-cost solar cell materials such as conjugated polymers, semiconductor nanocrystals, and organic small molecules which could compete with fossil fuels. To create cost-competitive devices, understanding the excited state dynamics of these materials is necessary. The first section of this thesis looks at aggregation in poly(3-hexylthiophene) (P3HT) which is commonly used in organic photovoltaics. The amount of aggregation in P3HT thin films was controlled by using a mixture of regioregular and regiorandom P3HT. Even with few aggregates present, excited states were found to transfer from amorphous to aggregate domains in fits and the most reasonable fitting parameters.

  1. Photovoltaic devices from CdSe nanocrystals and conjugated polymer composites

    Institute of Scientific and Technical Information of China (English)

    LIU Yanshan; WANG Li; CAO Yong

    2007-01-01

    The preparation of CdSe nanospheres (ns-CdSe) and their application as electron acceptor in conjugated polymer photovoltaic devices are reported, ns-CdSe with diameters of 5 nm were prepared through an organometallic method. The transmission electron microscopy (TEM),ultraviolet-visible (UV-Vis) absorption and photolumines-cence (PL) spectra indicate that the CdSe nanocrystals (NCs) are monodispersed nanospheres with the first exciton absorption peak at around 625 nm and the emission peakat around 652 nm. The PL spectra of the ns-CdSe/polymer composite films show that the PL of the conjugated polymers is effectively quenched upon the addition of ns-CdSe.Photovoltaic devices were fabricated from the compositesof ns-CdSe and poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) or poly(3-hexylthiophene)(P3HT). Under AM 1.5 illumination (100 mW/cm2), the short circuit current (ISC), open circuit voltage (V), fill factor (FF)and energy conversion efficiency (η) reached 1.56 mA/cm2,0.75 V, 34.5% and 0.40%, respectively for device from the ns-CdSe/MEH-PPV (15:1 by weight) and 1.93 mA/cm2,0.65 V, 38.4% and 0.48%, respectively for device from the ns-CdSe/P3HT (10 : 1 by weight).

  2. Applications of conducting polymers: robotic fins and other devices

    Science.gov (United States)

    Tangorra, James L.; Anquetil, Patrick A.; Weideman, Nathan S.; Fofonoff, Timothy; Hunter, Ian W.

    2007-04-01

    Conducting polymers are becoming viable engineering materials and are gradually being integrated into a wide range of devices. Parallel efforts conducted to characterize their electromechanical behavior, understand the factors that affect actuation performance, mechanically process films, and address the engineering obstacles that must be overcome to generate the forces and displacements required in real-world applications have made it possible to begin using conducting polymers in devices that cannot be made optimal using traditional actuators and materials. The use of conducting polymers has allowed us to take better advantage of biological architectures for robotic applications and has enabled us to pursue the development of novel sensors, motors, and medical diagnostic technologies. This paper uses the application of conducting polymer actuators to a biorobotic fin for unmanned undersea vehicles (UUVs) as a vehicle for discussing the efforts in our laboratory to develop conducting polymers into a suite of useful actuators and engineering components.

  3. Potential profile in a conducting polymer strip

    DEFF Research Database (Denmark)

    Bay, Lasse; West, Keld; Vlachopoulos, Nikolaos;

    2002-01-01

    Many conjugated polymers show an appreciable difference in volume between their oxidized and reduced forms. This property can be utilized in soft electrochemically driven actuators, "artificial muscles". Several geometries have been proposed for the conversion of the volume expansion into useful...... mechanical work. In a particularly simple geometry, the length change of polymer strips is exploited. The polymer strips are connected to the driving circuit at the end of the strip that is attached to the support of the device. The other end of the strip is connected to the load. The advantage of this set......-up is simplicity and that the maximum force generated in the polymer can be transferred directly to the load. There is, however, an inherent problem in this design that will be examined in this paper. If the potential of the reduced state is below that for oxygen reduction, only a finite length of the free...

  4. Pedot and PPy Conducting Polymer Bilayer and Trilayer Actuators

    DEFF Research Database (Denmark)

    Zainudeen, Umer Lebbe; Careem, Mohamed Abdul; Skaarup, Steen

    2008-01-01

    attempts have been made to improve the actuator performance. We report electromechanical measurements on actuators of bilayer and trilayer free standing films prepared with polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymers. Both types of conducting polymer are pre...

  5. Direct measurement of the microscale conductivity of conjugated polymer monolayers

    DEFF Research Database (Denmark)

    Bøggild, Peter; Grey, Francois; Hassenkam, T.;

    2000-01-01

    The in-plane conductivity of conjugated polymer monolayers is mapped here for the first time on the microscale using a novel scanning micro four-point probe (see Figure). The probe allows the source, drain, and voltage electrodes to be positioned within the same domain and the mapping results...... demonstrate how microscopic ordering in the polymer domains controls the conductivity....

  6. Design of a multi-coordinating polymer as a platform for functionalizing metal, metal oxide and semiconductor nanocrystals

    Science.gov (United States)

    Wang, Wentao; Ji, Xin; Kapur, Anshika; Mattoussi, Hedi

    2016-03-01

    We introduce a new set of amphiphilic polymers as multifunctional, metal-coordinating ligands adapted to surfacefunctionalize quantum dots (QDs), iron oxide nanoparticles (IONPs) and gold nanoparticles/nanorods (AuNPs/AuNRs). The ligand design relies on the introduction of several anchoring groups, hydrophilic moieties and reactive functionalities into a polymer chain, via one-step nucleophilic addition reaction. Such synthetic scheme also allows the insertion of target biomolecules during the ligand synthesis. This functionalization strategy yields nanocrystals that exhibit long-term colloidal stability over a broad range of biological conditions, such as pH changes and when mixed with growth media. When zwitterion groups are used as hydrophilic motifs, this provides compact nanocrystals that are compatible with conjugation to proteins via metal-polyhistidine self-assembly. In addition, we show that QDs ligated with these polymers can engage in energy or charge transfer interactions. Furthermore, nanocrystals coated with folic acid-modified polymers could promote the delivery of nanoparticle-conjugates into cancer cells via folate receptormediated endocytosis.

  7. Self-assembled hybrid materials based on conjugated polymers and semiconductors nano-crystals for plastic solar cells

    International Nuclear Information System (INIS)

    This work is devoted to the elaboration of self-assembled hybrid materials based on poly(3- hexyl-thiophene) and CdSe nano-crystals for photovoltaic applications. For that, complementary molecular recognition units were introduced as side chain groups on the polymer and at the nano-crystals' surface. Diamino-pyrimidine groups were introduced by post-functionalization of a precursor copolymer, namely poly(3-hexyl-thiophene-co-3- bromo-hexyl-thiophene) whereas thymine groups were introduced at the nano-crystals' surface by a ligand exchange reaction with 1-(6-mercapto-hexyl)thymine. However, due to their different solubility, the mixing of the two components by solution processes is difficult. A 'one-pot' procedure was developed, but this method led to insoluble aggregates without control of the hybrid composition. To overcome the solubility problem, the layer-by-layer method was used to prepare the films. This method allows a precise control of the deposition process. Experimental parameters were tested in order to evaluate their impact on the resulting film. The films morphology was investigated by microscopy and X-Ray diffraction techniques. These analyses reveal an interpenetrated structure of nano-crystals within the polymer matrix rather than a multilayered structure. Electrochemical and spectro electrochemical studies were performed on the hybrid material deposited by the LBL process. Finally the materials were tested in a solar cell configuration and the I=f(V) curves reveals a clear photovoltaic behaviour. (author)

  8. Supramolecular Engineering of Hierarchically Self-Assembled, Bioinspired, Cholesteric Nanocomposites Formed by Cellulose Nanocrystals and Polymers.

    Science.gov (United States)

    Zhu, Baolei; Merindol, Remi; Benitez, Alejandro J; Wang, Baochun; Walther, Andreas

    2016-05-01

    Natural composites are hierarchically structured by combination of ordered colloidal and molecular length scales. They inspire future, biomimetic, and lightweight nanocomposites, in which extraordinary mechanical properties are in reach by understanding and mastering hierarchical structure formation as tools to engineer multiscale deformation mechanisms. Here we describe a hierarchically self-assembled, cholesteric nanocomposite with well-defined colloid-based helical structure and supramolecular hydrogen bonds engineered on the molecular level in the polymer matrix. We use reversible addition-fragmentation transfer polymerization to synthesize well-defined hydrophilic, nonionic polymers with a varying functionalization density of 4-fold hydrogen-bonding ureidopyrimidinone (UPy) motifs. We show that these copolymers can be coassembled with cellulose nanocrystals (CNC), a sustainable, stiff, rod-like reinforcement, to give ordered cholesteric phases with characteristic photonic stop bands. The dimensions of the helical pitch are controlled by the ratio of polymer/CNC, confirming a smooth integration into the colloidal structure. With respect to the effect of the supramolecular motifs, we demonstrate that those regulate the swelling when exposing the biomimetic hybrids to water, and they allow engineering the photonic response. Moreover, the amount of hydrogen bonds and the polymer fraction are decisive in defining the mechanical properties. An Ashby plot comparing previous ordered CNC-based nanocomposites with our new hierarchical ones reveals that molecular engineering allows us to span an unprecedented mechanical property range from highest inelastic deformation (strain up to ∼13%) to highest stiffness (E ∼ 15 GPa) and combinations of both. We envisage that further rational design of the molecular interactions will provide efficient tools for enhancing the multifunctional property profiles of such bioinspired nanocomposites. PMID:27067311

  9. Nuclear alkylated pyridine aldehyde polymers and conductive compositions thereof

    Science.gov (United States)

    Rembaum, A.; Singer, S. (Inventor)

    1970-01-01

    A thermally stable, relatively conductive polymer was disclosed. The polymer was synthesized by condensing in the presence of catalyst a 2, 4, or 6 nuclear alklylated 2, 3, or 4 pyridine aldehyde or quaternary derivatives thereof to form a polymer. The pyridine groups were liked by olefinic groups between 2-4, 2-6, 2-3, 3-4, 3-6 or 4-6 positions. Conductive compositions were prepared by dissolving the quaternary polymer and an organic charge transfer complexing agent such as TCNQ in a mutual solvent such as methanol.

  10. “Electro-Click” on Conducting Polymer Films

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Lind, Johan Ulrik; Daugaard, Anders Egede;

    An azide substituted 3,4-ethylenedioxythiophene monomer is polymerised to yield a PEDOT like polymer with available azide groups (Figure 1). The azide groups enable post polymerization functionalization of the conducting polymer using a 1,3 dipolar cycloaddition reaction – also denoted “click...... chemistry”. This facilitates the addition of compounds that can otherwise not withstand the polymerization conditions. Several biological active molecules have been attached and tested on the films. Furthermore conducting polymer microelectrodes can electrochemically generate the catalyst required...... for their own functionalization with high spatial resolution. Interdigitated microelectrodes prepared from the azide-containing conducting polymer were selectively functionalized in sequence by two alkyne-modified fluorophores by control of the applied potentials. “Electro-click” on conducting polymer films...

  11. White light generation tuned by dual hybridization of nanocrystals and conjugated polymers

    Science.gov (United States)

    Demir, Hilmi Volkan; Nizamoglu, Sedat; Ozel, Tuncay; Mutlugun, Evren; Ozge Huyal, Ilkem; Sari, Emre; Holder, Elisabeth; Tian, Nan

    2007-10-01

    Dual hybridization of highly fluorescent conjugated polymers and highly luminescent nanocrystals (NCs) is developed and demonstrated in multiple combinations for controlled white light generation with high color rendering index (CRI) (> 80) for the first time. The generated white light is tuned using layer-by-layer assembly of CdSe/ZnS core-shell NCs closely packed on polyfluorene, hybridized on near-UV emitting nitride-based light emitting diodes (LEDs). The design, synthesis, growth, fabrication and characterization of these hybrid inorganic organic white LEDs are presented. The following experimental realizations are reported: (i) layer-by-layer hybridization of yellow NCs (λPL=580 nm) and blue polyfluorene (λPL=439 nm) with tristimulus coordinates of (x, y)=(0.31, 0.27), correlated color temperature of Tc=6962 K and CRI of Ra=53.4; (ii) layer-by-layer assembly of yellow and green NCs (λPL=580 and 540 nm) and blue polyfluorene (λPL=439 nm) with (x, y)=(0.23, 0.30), Tc=14395 K and Ra=65.7; and (iii) layer-by-layer deposition of yellow, green and red NCs (λPL=580, 540 and 620 nm) and blue polyfluorene (λPL=439 nm) with (x, y)=(0.38, 0.39), Tc=4052 K and Ra= 83.0. The CRI is demonstrated to be well controlled and significantly improved by increasing multi-chromaticity of the NC and polymer emitters.

  12. Radiation induced synthesis of conducting polymer nanocomposite

    International Nuclear Information System (INIS)

    dose is increased, a gradual red shift in was observed. This indicates formation of larger particles with increasing irradiation dose. With increase in Ag concentration the absorption maximum shifts towards longer wavelengths (larger particle size formation). The XRD pattern of irradiated PANI exhibits four new diffraction peaks, corresponding to face centered cubic structure (fcc) of silver. With increasing of either AgNO3 concentration or irradiation dose the particle size was increased. FTIR spectra of Ag/PANI nano composites illustrate that the incorporation of silver nanoparticles in poly aniline matrix leads to small shift of some peaks to the higher wavelengths and also decreases in the intensity of other peaks, which indicates that the structural change of polymer occurs with doping. The variation of dc electrical conductivity for pure PANI and irradiated Ag/PANI nano composites showed that the dc electrical conductivity of the irradiated Ag/PANI nano composites is higher than that of pure PANI and also it increases with increasing either irradiation dose or AgNO3 concentrations. Catalytic evaluation of Ag/PANI and Ag/PVA in the reduction of 4-Nitro phenol (4-NP) showed that, either Ag/PANI or Ag/PVA is successive catalyst for a reduction of 4-nitrophenol which a carcinogenic material present in waste water and some petroleum product.

  13. Conducting Polymer Actuators: Prospects and Limitations

    DEFF Research Database (Denmark)

    Skaarup, Steen

    Actuators constructed with a conjugated polymer as the active part have been predicted to have a number of highly desirable properties: Large mechanical strength, high power density, i.e. high actuation speeds possible, sufficient maximum strain values, high reversibility and safe, low voltages (...

  14. Mediating conducting polymer growth within hydrogels by controlling nucleation

    OpenAIRE

    A. J. Patton; Green, R A; L. A. Poole-Warren

    2015-01-01

    This study examines the efficacy of primary and secondary nucleation for electrochemical polymerisation of conductive polymers within poly(vinyl alcohol) methacrylate hydrogels. The two methods of nucleation investigated were a primary heterogeneous mechanism via introduction of conductive bulk metallic glass (Mg64Zn30Ca5Na1) particles and a secondary mechanism via introduction of “pre-polymerised” conducting polymer within the hydrogel (PEDOT:PSS). Evidence of nucleation was not seen in the ...

  15. Investigation of vapour-grown conductive polymer/heteropolyacid electrodes

    International Nuclear Information System (INIS)

    Heteropolyacid-doped conductive polymer coatings were grown by vapour transport of monomer (pyrrole or N-methylpyrrole) onto carbon paper coated with aqueous oxidant solutions (heteropolyacids or iron(III) chloride). Coated electrodes were studied by scanning electron microscopy and cyclic voltammetry. Polymer/heteropolyanion coatings had smooth morphologies giving pseudocapacitance of up to 422 F g-1 (with respect to active polymer material) and 0.45 F cm-2 (geometric area of the electrode)

  16. Ionic motion in PEDOT and PPy conducting polymer bilayers

    DEFF Research Database (Denmark)

    Zainudeen, Umer L.; Careem, M.A.; Skaarup, Steen

    2006-01-01

    Conducting polymer bilayers with poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy), each containing dodecyl benzenesulfonate (DBS) as immobile dopant species, were synthesized galvanostatically. The electrochemical behaviour of the bilayers was investigated using cyclic voltammetry......, optical absorption spectroscopy and electrochemical quartz crystal microbalance (EQCM) techniques. Two important conclusions of relevance for actuator performance were reached: It is possible to make a bilayer film that does not delaminate – the two polymers are compatible; and both polymers are active in...

  17. Recent developments in polyurethane-based conducting polymer composites

    OpenAIRE

    Njuguna, James A. K.; Pielichowski, Krzysztof

    2004-01-01

    Polyurethane-based conducting composites with polyaniline, polythiophene or polypyrrole are in the class of modern macromolecular materials that combine the toughness and elasticity of polyurethane matrix with conductivity of intrinsically conducting polymers. Since the methods of preparation strongly influence the structure and properties of resulting composite/blend, this works aim at systematic description of polyurethane based conducting composites. This review has been ...

  18. Measurement of thermal conductivity of PbTe nanocrystal coated glass fibers by the 3ω method.

    Science.gov (United States)

    Finefrock, Scott W; Wang, Yan; Ferguson, John B; Ward, James V; Fang, Haiyu; Pfluger, Jonathan E; Dudis, Douglas S; Ruan, Xiulin; Wu, Yue

    2013-11-13

    Fiber-based thermoelectric materials can conform to curved surfaces to form energy harvesting devices for waste heat recovery. Here we investigate the thermal conductivity in the axial direction of glass fibers coated with lead telluride (PbTe) nanocrystals using the self-heated 3ω method particularly at low frequency. While prior 3ω measurements on wire-like structures have only been demonstrated for high thermal conductivity materials, the present work demonstrates the suitability of the 3ω method for PbTe nanocrystal coated glass fibers where the low thermal conductivity and high aspect ratio result in a significant thermal radiation effect. We simulate the experiment using a finite-difference method that corrects the thermal radiation effect and extract the thermal conductivity of glass fibers coated by PbTe nanocrystals. The simulation method for radiation correction is shown to be generally much more accurate than analytical methods. We explore the effect of nanocrystal volume fraction on thermal conductivity and obtain results in the range of 0.50-0.93 W/mK near room temperature.

  19. Research Trends of Soft Actuators based on Electroactive Polymers and Conducting Polymers

    Science.gov (United States)

    Kaneto, K.

    2016-04-01

    Artificial muscles (or soft actuators) based on electroactive polymers (EAPs) are attractive power sources to drive human-like robots in place of electrical motor, because they are quiet, powerful, light weight and compact. Among EAPs for soft actuators, conducting polymers are superior in strain, stress, deformation form and driving voltage compared with the other EAPs. In this paper, the research trends of EAPs and conducting polymers are reviewed by retrieval of the papers and patents. The research activity of EAP actuators showed the maximum around 2010 and somehow declining now days. The reasons for the reducing activity are found to be partly due to problems of conducting polymer actuators for the practical application. The unique characteristics of conducting polymer actuators are mentioned in terms of the basic mechanisms of actuation, creeping, training effect and shape retention under high tensile loads. The issues and limitation of conducting polymer soft actuators are discussed.

  20. Making Conductive Polymers By Arc Tracking

    Science.gov (United States)

    Daech, Alfred F.

    1992-01-01

    Experimental technique for fabrication of electrically conductive polymeric filaments based on arc tracking, in which electrical arc creates conductive carbon track in material that initially was insulator. Electrically conductive polymeric structures made by arc tracking aligned along wire on which formed. Alignment particularly suited to high conductivity and desirable in materials intended for testing as candidate superconductors.

  1. Light harvesting by dye linked conducting polymers

    DEFF Research Database (Denmark)

    Nielsen, Kim Troensegaard

    2006-01-01

    The fact that the fossil fuel is finite and that the detrimental long-term effects of letting CO2 into our atmosphere exist, have created an enormous interest in developing new, cheap, renewable and less polluting energy resources. One of the most obviousabundant sources of energy in the solar...... shall be able to compete with the silicon solar cells. One of the parameters is to ensure a high degree of charge carrier separation. Charge carrier separationcan only happen at heterojunctions, which cover for example the interfaces between the polymers and the electrodes or the interface between...... greenish blue light while LEDs made of NPN emits light in the nearinfrared region. During the synthesis of Nnand NPN it was found that remnants of the palladium catalysts caused problems in the control of the polymers and further made the resistance in the solar cells and LEDs so low that they did not work...

  2. Processing of conductive filled polymers using microinjection

    OpenAIRE

    A.G. Pereira; Vieira, M. T.; Pontes, A.J.

    2011-01-01

    Polystyrene granules were coated by sputtering with an innovative film of stainless steel obtaining this way a composite. To compare results it was necessary to prepare two different composites, mixing polymer granules with steel fibers mechanically in a drum. Microinjection molding is a processing technique that allowed obtaining a representative sample of each composite. Scanning electron microscope (SEM) allowed the characterization of the coating thickness ...

  3. Microwave assisted click chemistry on a conductive polymer film

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hansen, Thomas S.; Larsen, Niels Bent;

    2011-01-01

    Microwave (MW) irradiation has been used to accelerate the functionalization of an azide functional poly(3,4-ethylenedioxythiophene) film by click chemistry. The absorption of MW energy by the conductive polymer has been exploited for localized activation of the reaction on the polymer surface...

  4. Current Trends in Sensors Based on Conducting Polymer Nanomaterials

    Directory of Open Access Journals (Sweden)

    Hyeonseok Yoon

    2013-08-01

    Full Text Available Conducting polymers represent an important class of functional organic materials for next-generation electronic and optical devices. Advances in nanotechnology allow for the fabrication of various conducting polymer nanomaterials through synthesis methods such as solid-phase template synthesis, molecular template synthesis, and template-free synthesis. Nanostructured conducting polymers featuring high surface area, small dimensions, and unique physical properties have been widely used to build various sensor devices. Many remarkable examples have been reported over the past decade. The enhanced sensitivity of conducting polymer nanomaterials toward various chemical/biological species and external stimuli has made them ideal candidates for incorporation into the design of sensors. However, the selectivity and stability still leave room for improvement.

  5. Conducting polymer electrodes for gel electrophoresis.

    Directory of Open Access Journals (Sweden)

    Katarina Bengtsson

    Full Text Available In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene (PEDOT can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  6. Conducting Polymers Functionalized with Phthalocyanine as Nitrogen Dioxide Sensors

    Directory of Open Access Journals (Sweden)

    S. D. Deshpande

    2002-05-01

    Full Text Available The conducting polymers such as polyaniline, polypyrrole and polythiophene were functionalized with copper phthalocyanine using chemical oxidation method. The obtained polymers viz. PANI-CuPc, PPy-CuPc and PT-CuPc were studied as chemical sensors by their response characteristics after exposure to various chemical vapors such as methanol, ammonia and nitrogen dioxide. The results obtained showed that these polymers have moderate sensitivity towards the methanol as well as ammonia vapors whereas they show tremendous sensitivity towards nitrogen dioxide vapors. The sensitivity factor of as high as 50,000 was obtained for PT-CuPc polymers in nitrogen dioxide. In comparison to this, the sensitivity factors of about 100 and 40 were obtained, when these polymers were exposed to ammonia and methanol vapors. The very high selectivity towards the nitrogen dioxide was explained on the basis of charge transfer complex formed between, the phthalocyanine donor and nitrogen dioxide acceptor molecules. On the other hand, ammonia becomes a competing electron donor in CuPc containing conducting polymers. The very low response towards the methanol may be explained on the basis very little charge transfer / interaction between CuPc containing polymers and methanol. Thus, CuPc incorporated conducting polymers have much higher selectivity than their original homopolymer.

  7. Enhanced Conductivity in CZTS/Cu(2-x)Se Nanocrystal Thin Films: Growth of a Conductive Shell.

    Science.gov (United States)

    Korala, Lasantha; McGoffin, J Tyler; Prieto, Amy L

    2016-02-01

    Poor charge transport in Cu2ZnSnS4 (CZTS) nanocrystal (NC) thin films presents a great challenge in the fabrication of solar cells without postannealing treatments. We introduce a novel approach to facilitate the charge carrier hopping between CZTS NCs by growing a stoichiometric Cu2Se shell that can be oxidized to form a conductive Cu2-xSe phase when exposed to air. The CZTS/Cu2Se core/shell NCs with varying numbers of shell monolayers were synthesized by the successive ionic layer adsorption and reaction (SILAR) method, and the variation in structural and optical properties of the CZTS NCs with varying shell thicknesses was investigated. Solid-phase sulfide ligand exchange was employed to fabricate NC thin films by layer-by-layer dip coating and a 2 orders of magnitude rise in dark conductivity (∼10(-3) S cm(-1) at 0 monolayer and ∼10(-1) S cm(-1) at 1.5 monolayers) was observed with an increase in the number of shell monolayers. The approach described herein is the first key step in achieving a significant increase in the photoconductivity of as-deposited CZTS NC thin films. PMID:26745286

  8. Applications of scanning probe microscopy in intrinsically conducting polymer research

    Institute of Scientific and Technical Information of China (English)

    YANG Tao; NIU Li; LI Zhuang; DONG Shaojun

    2007-01-01

    The applications of scanning probe microscopy(SPM)in intrinsically conducting polymer research is briefly reviewed,including morphology observation,nanofabrication,microcosmic electrical property measurements,electrochemistry researches,in-situ measurements of film thickness change,and so on.At the same time,some important variations of SPM and the related techniques are briefly introduced.Finally,the future development of SPM in the study of intrinsically conducting polymers is prospected.

  9. Chemical sensors using peptide-functionalized conducting polymer nanojunction arrays

    Science.gov (United States)

    Aguilar, Alvaro Díaz; Forzani, Erica S.; Li, Xiulan; Tao, Nongjian; Nagahara, Larry A.; Amlani, Islamshah; Tsui, Raymond

    2005-11-01

    We demonstrate a heavy metal-ion sensor for drinking water analysis using a conducting polymer nanojunction array. Each nanojunction is formed by bridging a pair of nanoelectrodes separated with a small gap (sensor is based on the change in the nanojunction conductance as a result of polymer conformational changes induced by the metal-ion chelating peptide. The nanojunction sensor allows real-time detection of Cu2+ and Ni2+ at ppt range.

  10. Novel synthetic methods to produce functionalized conducting polymers. 1. Polyanilines

    Energy Technology Data Exchange (ETDEWEB)

    Barbero, C.; Salavagione, H.J.; Acevedo, D.F.; Garay, F.; Planes, G.A.; Miras, M.C. [Universidad Nacional de Rio Cuarto (Argentina). Dpto. de Quimica; Grumelli, D.E. [INQUIMAE, Buenos Aires (Argentina). Dpto. de Quimica Inorganica; Morales, G.M. [University of Chicago (United States). Dept. of Chemistry

    2004-09-15

    Recent results, part of an ongoing research programme aimed to develop synthetic methods which could be used to functionalise conducting polymers, are described. Among those methods are the copolymerization of aniline with substituted anilines and post-modification reactions of polyaniline, such as: electrophilic substitution, nucleophilic addition and coupling with diazonium salts. Some of those methods could be chemically or electrochemically controlled allowing a quantitative tailoring of the modification. The effect of the added functionalities on the electrochemical properties of the polymers is investigated using spectroscopic and electrochemical techniques. The extension of the synthetic methods to combinatorial modification of conductive polymers is also discussed. (author)

  11. FTIR AND IONIC CONDUCTIVITY STUDIES ON BLEND POLYMER ELECTROLYTES

    Directory of Open Access Journals (Sweden)

    J. Senthil

    2011-08-01

    Full Text Available Investigations on structural and conductivity properties of solid polymer complexes have attracted a high degree of attention. The main applications of solid polymer electrolytes (SPEs are found in varioussecondary batteries and energy conversion units. In view of the abundant resources, low costs and relatively low reactivity of magnesium, solid-state batteries using magnesium metal are worthy of investigations. The polymer electrolytes were prepared using poly methyl methacrylate (PMMA, poly vinyl chloride (PVC and magnesium chloride (MgCl2 by solvent casting technique. The complex formation and ionic conductivity were characterized by Fourier Transform Infra Red spectroscopy (FTIR and impedance spectroscopy respectively.The FTIR studies provide the evidence of interaction of cation Mg2+ with the polymers. The maximum conductivity found for PMMA-MgCl2 is 0.57 x 10-7 Scm-1 at room temperature.

  12. Light harvesting by dye linked conducting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Troensegaard Nielsen, K.

    2006-06-15

    The fact that the fossil fuel is finite and that the detrimental long-term effects of letting CO2 into our atmosphere exist, have created an enormous interest in developing new, cheap, renewable and less polluting energy resources. One of the most obvious abundant sources of energy in the solar system is the sun. Unfortunately the well developed silicon solar cells are very costly to produce. In an attempt to produce cheap and flexible solar cells, plastic solar cells have received a lot of attention in the last decades. There are still a lot of parameters to optimize if the plastic solar cell shall be able to compete with the silicon solar cells. One of the parameters is to ensure a high degree of charge carrier separation. Charge carrier separation can only happen at heterojunctions, which cover for example the interfaces between the polymers and the electrodes or the interface between an n-conductor and a p-conductor. The facts that the charge carrier separation only happens at the heterojunctions limits the thickness of the active layer in solar cells and thereby the effectiveness of the solar cells. In this project the charge carrier separation is attempted optimized by making plastic solar cells with a molecular heterojunction. The molecular heterojunction has been obtained by synthesizing a three domain super molecular assembly termed NPN. NPN consists of two poly[1-(2,5-dioctyltolanyl)ethynylene] chains (N-domains) coupled to the [10,20-bis(3,5-bistert-butylphenyl]-5,15-dibromoporphinato]zinc(II) (P-domain). It is shown that the N domains in NPN work as effective light harvesting antennas for the P domain and effectively transfer electrically generated excitons in the N domain to the P domain. Unfortunately the P domain does not separate the charge carriers but instead works as a charge carrier trap. This results in a performance of solar cells made of NPN that is much lower than the performance of solar cells made of pure poly[1-(2,5-dioctyltolanyl

  13. Hopping conductivity and insulator-metal transition in films of touching semiconductor nanocrystals

    Science.gov (United States)

    Fu, Han; Reich, K. V.; Shklovskii, B. I.

    2016-03-01

    This paper is focused on the variable-range hopping of electrons in semiconductor nanocrystal (NC) films below the critical doping concentration nc at which it becomes metallic. The hopping conductivity is described by the Efros-Shklovskii law, which depends on the localization length of electrons. We study how the localization length grows with the doping concentration n in the film of touching NCs. For that we calculate the electron transfer matrix element t (n ) between neighboring NCs for two models when NCs touch by small facets or just one point. We study two sources of disorder: variations of NC diameters and random Coulomb potentials originating from random numbers of donors in NCs. We use the ratio of t (n ) to the disorder-induced NC level dispersion to find the localization length of electrons due to the multistep elastic co-tunneling process. We found three different phases at n conductivity) oscillates with n from the insulator base, and (3) "blinking metal" where the localization length periodically diverges. The first two phases were seen experimentally and we discuss how one can see the more exotic third one. In all three, the localization length diverges at n =nc . This allows us to find nc.

  14. Rapid synthesis of flexible conductive polymer nanocomposite films

    International Nuclear Information System (INIS)

    Polymer nanocomposite films with nanoparticle-specific properties are sought out in novel functional materials and miniaturized devices for electronic and biomedical applications. Sensors, capacitors, actuators, displays, circuit boards, solar cells, electromagnetic shields and medical electrodes rely on flexible, electrically conductive layers or films. Scalable synthesis of such nanocomposite films, however, remains a challenge. Here, flame aerosol deposition of metallic nanosliver onto bare or polymer-coated glass substrates followed by polymer spin-coating on them leads to rapid synthesis of flexible, free-standing, electrically conductive nanocomposite films. Their electrical conductivity is determined during their preparation and depends on substrate composition and nanosilver deposition duration. Accordingly, thin (<500 nm) and flexible nanocomposite films are made having conductivity equivalent to metals (e.g. 5  × 104 S cm−1), even during repetitive bending. (paper)

  15. Rapid synthesis of flexible conductive polymer nanocomposite films.

    Science.gov (United States)

    Blattmann, C O; Sotiriou, G A; Pratsinis, S E

    2015-03-27

    Polymer nanocomposite films with nanoparticle-specific properties are sought out in novel functional materials and miniaturized devices for electronic and biomedical applications. Sensors, capacitors, actuators, displays, circuit boards, solar cells, electromagnetic shields and medical electrodes rely on flexible, electrically conductive layers or films. Scalable synthesis of such nanocomposite films, however, remains a challenge. Here, flame aerosol deposition of metallic nanosliver onto bare or polymer-coated glass substrates followed by polymer spin-coating on them leads to rapid synthesis of flexible, free-standing, electrically conductive nanocomposite films. Their electrical conductivity is determined during their preparation and depends on substrate composition and nanosilver deposition duration. Accordingly, thin (conductivity equivalent to metals (e.g. 5  × 10(4) S cm(-1)), even during repetitive bending. PMID:25736387

  16. Mediating conducting polymer growth within hydrogels by controlling nucleation

    Directory of Open Access Journals (Sweden)

    A. J. Patton

    2015-01-01

    Full Text Available This study examines the efficacy of primary and secondary nucleation for electrochemical polymerisation of conductive polymers within poly(vinyl alcohol methacrylate hydrogels. The two methods of nucleation investigated were a primary heterogeneous mechanism via introduction of conductive bulk metallic glass (Mg64Zn30Ca5Na1 particles and a secondary mechanism via introduction of “pre-polymerised” conducting polymer within the hydrogel (PEDOT:PSS. Evidence of nucleation was not seen in the bulk metallic glass loaded gels, however, the PEDOT:PSS loaded gels produced charge storage capacities over 15 mC/cm2 when sufficient polymer was loaded. These studies support the hypothesis that secondary nucleation is an efficient approach to producing stand-alone conducting hydrogels.

  17. Phase diagram of hopping conduction mechanisms in polymer nanofiber network

    Science.gov (United States)

    Li, Jeng-Ting; Lu, Yu-Cheng; Jiang, Shiau-Bin; Zhong, Yuan-Liang; Yeh, Jui-Ming

    2015-12-01

    Network formation by nanofiber crosslinking is usually in polymer materials as application in organic semiconductor devices. Electron hopping transport mechanisms depend on polymer morphology in network. Conducting polymers morphology in a random network structure is modeled by a quasi-one-dimensional system coupled of chains or fibers. We observe the varying hopping conduction mechanisms in the polyaniline nanofibers of the random network structure. The average diameter d of the nanofibers is varied from approximately 10 to 100 nm. The different dominant hopping mechanisms including Efros-Shklovskii variable-range hopping (VRH), Mott VRH, and nearest-neighbor hopping are dependent on temperature range and d in crossover changes. The result of this study is first presented in a phase diagram of hopping conduction mechanisms based on the theories of the random network model. The hopping conduction mechanism is unlike in normal semiconductor materials.

  18. Phase diagram of hopping conduction mechanisms in polymer nanofiber network

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jeng-Ting; Lu, Yu-Cheng; Jiang, Shiau-Bin; Zhong, Yuan-Liang, E-mail: ylzhong@cycu.edu.tw [Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li 32023, Taiwan (China); Yeh, Jui-Ming [Department of Chemistry and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li 32023, Taiwan (China)

    2015-12-07

    Network formation by nanofiber crosslinking is usually in polymer materials as application in organic semiconductor devices. Electron hopping transport mechanisms depend on polymer morphology in network. Conducting polymers morphology in a random network structure is modeled by a quasi-one-dimensional system coupled of chains or fibers. We observe the varying hopping conduction mechanisms in the polyaniline nanofibers of the random network structure. The average diameter d of the nanofibers is varied from approximately 10 to 100 nm. The different dominant hopping mechanisms including Efros-Shklovskii variable-range hopping (VRH), Mott VRH, and nearest-neighbor hopping are dependent on temperature range and d in crossover changes. The result of this study is first presented in a phase diagram of hopping conduction mechanisms based on the theories of the random network model. The hopping conduction mechanism is unlike in normal semiconductor materials.

  19. Phase diagram of hopping conduction mechanisms in polymer nanofiber network

    International Nuclear Information System (INIS)

    Network formation by nanofiber crosslinking is usually in polymer materials as application in organic semiconductor devices. Electron hopping transport mechanisms depend on polymer morphology in network. Conducting polymers morphology in a random network structure is modeled by a quasi-one-dimensional system coupled of chains or fibers. We observe the varying hopping conduction mechanisms in the polyaniline nanofibers of the random network structure. The average diameter d of the nanofibers is varied from approximately 10 to 100 nm. The different dominant hopping mechanisms including Efros-Shklovskii variable-range hopping (VRH), Mott VRH, and nearest-neighbor hopping are dependent on temperature range and d in crossover changes. The result of this study is first presented in a phase diagram of hopping conduction mechanisms based on the theories of the random network model. The hopping conduction mechanism is unlike in normal semiconductor materials

  20. Preparation of Conductive Polymer Polyanilines for an Experiment for Students

    Science.gov (United States)

    Yano, Jun; Matsuzaki, Kiyoka; Ichimori, Hayato; Ito, Takeshi; Okano, Hiroshi; Osaki, Nobukazu

    For an organic and polymer chemistry experiment for students in university and college of technology, synthesis of conducting polymers was attempted. Three conductive polymers, polyaniline, poly (o-phenylenediamine) and poly (N-methylaniline) , were prepared by oxidative polymerizations of the corresponding monomers. Among four oxidizing agents, K2Cr2O7, KIO3, FeCl3 and (NH4) 2S2O8, (NH4) 2S2O8 was turned out to be the best oxidizing agent for the polymerizations. The polymerizing solutions gradually colored because of the formation of colored oligomers, which was monitored with the absorption spectra measured during the polymerizations. Since the time for experiment was limited, the molar ratio of [ (NH4) 2S2O8] to [monomer] was taken 2 : 1. The experiment was demonstrated in the organic and polymer chemistry experiments and was evaluated by students as well as teachers.

  1. Lithium ion conducting solid polymer blend electrolyte based on bio-degradable polymers

    Indian Academy of Sciences (India)

    Natarajan Rajeswari; Subramanian Selvasekarapandian; Moni Prabu; Shunmugavel Karthikeyan; C Sanjeeviraja

    2013-04-01

    Lithium ion conducting polymer blend electrolyte films based on poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) with different Mwt% of lithium nitrate (LiNO3) salt, using a solution cast technique, have been prepared. The polymer blend electrolyte has been characterized by XRD, FTIR, DSC and impedance analyses. The XRD study reveals the amorphous nature of the polymer electrolyte. The FTIR study confirms the complex formation between the polymer and salt. The shifts in g values of 70 PVA–30 PVP blend and 70 PVA–30 PVP with different Mwt% of LiNO3 electrolytes shown by DSC thermograms indicate an interaction between the polymer and the salt. The dependence of g and conductivity upon salt concentration has been discussed. The ion conductivity of the prepared polymer electrolyte has been found by a.c. impedance spectroscopic analysis. The PVA–PVP blend system with a composition of 70 wt% PVA: 30 wt% PVP exhibits the highest conductivity of 1.58 × 10-6 Scm-1 at room temperature. Polymer samples of 70 wt% PVA–30 wt% PVP blend with different molecular weight percentage of lithium nitrate with DMSO as solvent have been prepared and studied. High conductivity of 6.828 × 10-4 Scm-1 has been observed for the composition of 70 PVA:30 PVP:25 Mwt% of LiNO3 with low activation energy 0.2673 eV. The conductivity is found to increase with increase in temperature. The temperature dependent conductivity of the polymer electrolyte follows the Arrhenius relationship which shows hopping of ions in the polymer matrix. The relaxation parameters () and () of the complexes have been calculated by using loss tangent spectra. The mechanical properties of polymer blend electrolyte such as tensile strength, elongation and degree of swelling have been measured and the results are presented.

  2. Conducting polymers: nobel prize in chemistry, 2000

    OpenAIRE

    Menon, Reghu

    2000-01-01

    The Nobel Prize in Chemistry, 2000 has been awarded to Alan J. Heeger (University of California at Santa Barbara, USA), Alan G. MacDiarmid (University of Pennsylvania, USA) and Hideki Shirakawa4 (University of Tsukuba, Japan). The citation for the reward – ‘for the discovery and development of electrically conductive polymers’. Moreover, The Royal Swedish Academy of Sciences pointed out that the award is being motivated by the ‘important scientific position that the field has achieved and the...

  3. Electrochemical Analysis of Conducting Polymer Thin Films

    OpenAIRE

    Bin Wang; Vyas, Ritesh N.

    2010-01-01

    Polyelectrolyte multilayers built via the layer-by-layer (LbL) method has been one of the most promising systems in the field of materials science. Layered structures can be constructed by the adsorption of various polyelectrolyte species onto the surface of a solid or liquid material by means of electrostatic interaction. The thickness of the adsorbed layers can be tuned precisely in the nanometer range. Stable, semiconducting thin films are interesting research subjects. We use a conducting...

  4. Electrical characterization of proton conducting polymer electrolyte based on bio polymer with acid dopant

    Science.gov (United States)

    Kalaiselvimary, J.; Pradeepa, P.; Sowmya, G.; Edwinraj, S.; Prabhu, M. Ramesh

    2016-05-01

    This study describes the biodegradable acid doped films composed of chitosan and Perchloric acid with different ratios (2.5 wt %, 5 wt %, 7.5 wt %, 10 wt %) was prepared by the solution casting technique. The temperature dependence of the proton conductivity of complex electrolytes obeys the Arrhenius relationship. Proton conductivity of the prepared polymer electrolyte of the bio polymer with acid doped was measured to be approximately 5.90 × 10-4 Scm-1. The dielectric data were analyzed using Complex impedance Z*, Dielectric loss ɛ', Tangent loss for prepared polymer electrolyte membrane with the highest conductivity samples at various temperature.

  5. A Conducting Polymer Film Stronger Than Aluminum

    Science.gov (United States)

    Shi, Gaoquan; Jin, Shi; Xue, Gi; Li, Cun

    1995-02-01

    Polythiophene (Pth) was electrochemically deposited onto stainless steel substrate from freshly distilled boron fluoride-ethyl ether containing 10 millimoles of thiophene per liter. The free-standing Pth film obtained at an applied potential of 1.3 volts (versus Ag/AgCl) had a conductivity of 48.7 siemens per centimeter. Its tensile strength (1200 to 1300 kilograms per square centimeter) was greater than that of aluminium (1000 to 1100 kilograms per square centimeter). This Pth film behaves like a metal sheet and can be easily cut into various structures with a knife or a pair of scissors.

  6. Study of PEDOT conductive polymer films by admittance measurements

    International Nuclear Information System (INIS)

    Research highlights: → Microwave technique to measure the conductivity of PEDOT films. → PEDOT conductivity depends on its mesoscopic scale structure and oxidation level. → Raman spectroscopy and SEM analysis to study structure and morphology of PEDOT. → Microwave measurements allow determination of the macroscopic scale conductivity. → Microwave measurements overcome problems related to the local structural defects and inhomogeneities of PEDOT. - Abstract: In this paper we propose the use of a microwave technique to measure the conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) films. The PEDOT layers were prepared by electropolymerization from aqueous solutions using both poly(sodium 4-styrene sulphonate) (NaPSS) and sodium dodecyl sulphate (NaDS) acting as monomer solubilizer and dopant for the polymer. The conductive properties of a series of samples produced under different synthesis conditions and characterized by different structures have been investigated by microwave measurements in the frequency range from 40 MHz to 40 GHz by using a Corbino disc geometry. Such technique allows to estimate the mean conductivity of the polymer samples overcoming the limitations of the measuring configurations typically imposed by the conventional d.c. measurements. The morphology of PEDOT films and the structure of polymer chains were studied by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. The correlated morphological, structural and microwave analysis enabled us to evidence several factors that affect the macroscopic scale conductivity of the polymer sample films and to identify the conditions for preparation of PEDOT films with functional properties relevant to technological applications.

  7. Preparation of Conducting Polymers by Electrochemical Methods and Demonstration of a Polymer Battery

    Science.gov (United States)

    Goto, Hiromasa; Yoneyama, Hiroyuki; Togashi, Fumihiro; Ohta, Reina; Tsujimoto, Akitsu; Kita, Eiji; Ohshima, Ken-ichi

    2008-01-01

    The electrochemical polymerization of aniline and pyrrole, and demonstrations of electrochromism and the polymer battery effect, are presented as demonstrations suitable for high school and introductory chemistry at the university level. These demonstrations promote student interest in the electrochemical preparation of conducting polymers, where…

  8. Corrosion Protection of Steels by Conducting Polymer Coating

    Directory of Open Access Journals (Sweden)

    Toshiaki Ohtsuka

    2012-01-01

    Full Text Available The corrosion protection of steels by conducting polymer coating is reviewed. The conducting polymer such as polyaniline, polypyrrole, and polythiophen works as a strong oxidant to the steel, inducing the potential shift to the noble direction. The strongly oxidative conducting polymer facilitates the steel to be passivated. A bilayered PPy film was designed for the effective corrosion protection. It consisted of the inner layer in which phosphomolybdate ion, PMo12O3−40 (PMo, was doped and the outer layer in which dodecylsulfate ion (DoS was doped. The inner layer stabilized the passive oxide and the outer possessed anionic perm-selectivity to inhibit the aggressive anions such as chloride from penetrating through the PPy film to the substrate steel. By the bilayered PPy film, the steel was kept passive for about 200 h in 3.5% sodium chloride solution without formation of corrosion products.

  9. Tunable Nanopatterning of Conductive Polymers via Electrohydrodynamic Lithography

    OpenAIRE

    Rickard, Jonathan James Stanley; Farrer, Ian; Goldberg Oppenheimer, Pola

    2016-01-01

    An increasing number of technologies require the fabrication of conductive structures on a broad range of scales and over large areas. Here, we introduce advanced yet simple electrohydrodynamic lithography (EHL) for patterning conductive polymers directly on a substrate with high fidelity. We illustrate the generality of this robust, low-cost method by structuring thin polypyrrole films via electric-field-induced instabilities, yielding well-defined conductive structures with feature sizes ra...

  10. Spontaneous Emission Enhancement from polymer-embedded colloidal PbS Nanocrystals into Si-based photonics at telecom wavelengths

    CERN Document Server

    Humer, Markus; Jantsch, Wolfgang; Fromherz, Thomas

    2013-01-01

    We experimentally demonstrate the coupling of optically excited PbS nanocrystal (NC) photoluminescence (PL) into Si-based ring resonators and waveguides at 300K. The PbS NCs are dissolved into Novolak polymer at various concentrations and applied by drop-casting. The coupling mechanism and the spontaneous emission enhancement are experimentally investigated and compared to theoretical predictions. Quality (Q) factors of 2500 were obtained in emission and transmission for wavelengths centered around 1.45{\\mu}m. PL intensity shows a linear dependence on the excitation power and no degradation of the Q factors. Devices with stable optical properties are obtained by this versatile technique.

  11. Patterning and Conductivity Modulation of Conductive Polymers by UV Light Exposure

    DEFF Research Database (Denmark)

    Edberg, Jesper; Iandolo, Donata; Brooke, Robert;

    2016-01-01

    to control the conductivity in the conjugated polymer poly(3,4-ethylenedioxythiophene):tosylate by more than six orders of magnitude in addition to producing high-resolution patterns and optical gradients. The mechanism behind the modulation in the polymerization kinetics by UV light irradiation as well......A novel patterning technique of conductive polymers produced by vapor phase polymerization is demonstrated. The method involves exposing an oxidant film to UV light which changes the local chemical environment of the oxidant and subsequently the polymerization kinetics. This procedure is used...... as the properties of the resulting polymer are investigated....

  12. Corrosion-protective coatings from electrically conducting polymers

    Science.gov (United States)

    Thompson, Karen Gebert; Bryan, Coleman J.; Benicewicz, Brian C.; Wrobleski, Debra A.

    1991-01-01

    In a joint effort between NASA Kennedy and LANL, electrically conductive polymer coatings were developed as corrosion protective coatings for metal surfaces. At NASA Kennedy, the launch environment consist of marine, severe solar, and intermittent high acid and/or elevated temperature conditions. Electrically conductive polymer coatings were developed which impart corrosion resistance to mild steel when exposed to saline and acidic environments. Such coatings also seem to promote corrosion resistance in areas of mild steel where scratches exist in the protective coating. Such coatings appear promising for many commercial applications.

  13. Orienting semi-conducting π-conjugated polymers.

    Science.gov (United States)

    Brinkmann, Martin; Hartmann, Lucia; Biniek, Laure; Tremel, Kim; Kayunkid, Navaphun

    2014-01-01

    The present review focuses on the recent progress made in thin film orientation of semi-conducting polymers with particular emphasis on methods using epitaxy and shear forces. The main results reported in this review deal with regioregular poly(3-alkylthiophene)s and poly(dialkylfluorenes). Correlations existing between processing conditions, macromolecular parameters and the resulting structures formed in thin films are underlined. It is shown that epitaxial orientation of semi-conducting polymers can generate a large palette of semi-crystalline and nanostructured morphologies by a subtle choice of the orienting substrates and growth conditions.

  14. Mechanism of actuation in conducting polymers: Osmotic expansion

    DEFF Research Database (Denmark)

    Bay, Lasse; Jacobsen, Torben; West, Keld;

    2001-01-01

    Conducting polymers expand or contract when their redox state is changed. This expansion/contraction effect can be separated in an intrinsic part because of changes of the polymer backbone on reduction/oxidation and a part depending on the surrounding electrolyte phase, because of osmotic expansion...... of the polymer phase. The osmotic effect causes solvent molecules to move into the polymer in a number far in excess of those bound strongly in the solvation shell of the mobile ion, resulting in large volume changes. In this paper, a thermodynamic description of the osmotic expansion is worked out. The model...... is compared with measurements on PPy(DBS) films. The experiments show that the expansion decreases as the electrolyte concentration is increased. This means that a considerable part of the total expansion is due to the osmotic effect. The osmotic effect should be taken into account when interpreting...

  15. Fabrication, Modelling and Application of Conductive Polymer Composites

    Science.gov (United States)

    Price, Aaron David

    Electroactive polymers (EAP) are an emerging branch of smart materials that possess the capability to change shape in the presence of an electric field. Opportunities for the advancement of knowledge were identified in the branch of EAP consisting of inherently electrically conductive polymers. This dissertation explores methods by which the unique properties of composite materials having conductive polymers as a constituent may be exploited. Chapter 3 describes the blending of polyaniline with conventional thermoplastics. Processing these polyblends into foams yielded a porous conductive material. The effect of blend composition and processing parameters on the resulting porous morphology and electrical conductivity was investigated. These findings represent the first systematic study of porous conductive polymer blends. In Chapter 4, multilayer electroactive polymer actuators consisting of polypyrrole films electropolymerized on a passive polymer membrane core were harnessed as actuators. The membrane is vital in the transport of ionic species and largely dictates the stiffness of the layered configuration. The impact of the mechanical properties of the membrane on the actuation response of polypyrrole-based trilayer bending actuators was investigated. Candidate materials with distinct morphologies were identified and their mechanical properties were evaluated. These results indicated that polyvinylidene difluoride membranes were superior to the other candidates. An electrochemical synthesis procedure was proposed, and the design of a novel polymerization vessel was reported. These facilities were utilized to prepare actuators under a variety of synthesis conditions to investigate the impact of conductive polymer morphology on the electromechanical response. Characterization techniques were implemented to quantitatively assess physical and electrochemical properties of the layered composite. Chapter 5 proposes a new unified multiphysics model that captures the

  16. Advanced Proton Conducting Polymer Electrolytes for Electrochemical Capacitors

    Science.gov (United States)

    Gao, Han

    Research on solid electrochemical energy storage devices aims to provide high performance, low cost, and safe operation solutions for emerging applications from flexible consumer electronics to microelectronics. Polymer electrolytes, minimizing device sealing and liquid electrolyte leakage, are key enablers for these next-generation technologies. In this thesis, a novel proton-conducing polymer electrolyte system has been developed using heteropolyacids (HPAs) and polyvinyl alcohol for electrochemical capacitors. A thorough understanding of proton conduction mechanisms of HPAs together with the interactions among HPAs, additives, and polymer framework has been developed. Structure and chemical bonding of the electrolytes have been studied extensively to identify and elucidate key attributes affecting the electrolyte properties. Numerical models describing the proton conduction mechanism have been applied to differentiate those attributes. The performance optimization of the polymer electrolytes through additives, polymer structural modifications, and synthesis of alternative HPAs has achieved several important milestones, including: (a) high proton mobility and proton density; (b) good ion accessibility at electrode/electrolyte interface; (c) wide electrochemical stability window; and (d) good environmental stability. Specifically, high proton mobility has been addressed by cross-linking the polymer framework to improve the water storage capability at normal-to-high humidity conditions (e.g. 50-80% RH) as well as by incorporating nano-fillers to enhance the water retention at normal humidity levels (e.g. 30-60% RH). High proton density has been reached by utilizing additional proton donors (i.e. acidic plasticizers) and by developing different HPAs. Good ion accessibility has been achieved through addition of plasticizers. Electrochemical stability window of the electrolyte system has also been investigated and expanded by utilizing HPAs with different heteroatoms

  17. Effects of preparation temperature on the conductivity of polypyrrole conducting polymer

    Indian Academy of Sciences (India)

    Anuar Kassim; Zarina Bte Basar; H N M Ekramul Mahmud

    2002-04-01

    An attempt has been made to investigate the effect of temperature on the conductivity of polypyrrole conducting polymer films prepared by an electrochemical method in an aqueous medium using camphor sulfonate as the dopant. The polymer was grown from aqueous solutions employing a range of temperatures (1-60°C). It was found that with increase in temperature the conductivity decreased and the optimum temperature was found to be between 10 and 30°C. The results show that the polymer formed at low temperature has higher conductivity and is stronger than that formed at higher temperatures. Characterization by X-ray scattering shows that interlayer distance, Bragg (Å), increases with increasing temperature. The morphology of the films formed was studied by using a scanning electron microscope (SEM). The changes in conductivity and physical appearance were interpreted as being due to compactness in the molecular packing and formation of linkages in the film.

  18. Carbon nanotube and conducting polymer composites for supercapacitors

    Institute of Scientific and Technical Information of China (English)

    Chuang Peng; Shengwen Zhang; Daniel Jewell; George Z. Chen

    2008-01-01

    Composites of carbon nanotubes and conducting polymers can be prepared via chemical synthesis, electrochemical deposition on pre-formed carbon nanotube electrodes, or by electrochemical co-deposition. The composites combine the large pseudocapacitance of the conducting polymers with the fast charging/discharging double-layer capacitance and excellent mechanical properties of the carbon nanotubes. The electrochemically co-deposited composites are the most homogeneous and show an unusual interaction between thepolymer and nanotubes, giving rise to a strengthened electron delocalisation and conjugation along the polymer chains. As a result they exhibit excellent electrochemical charge storage properties and fast charge/discharge switching, making them promising electrode mate-rials for high power supercapacitors.

  19. Electrochemical Formation of Polypyrrole-carboxymethylcellulose Conducting Polymer Composite Films

    Institute of Scientific and Technical Information of China (English)

    H.N.M. Ekramul Mahmud; Anuar Kassim; Zulkarnain Zainal; Wan Mahmood Mat Yunus

    2005-01-01

    The electrochemical preparation of polypyrrole-carboxymethylcellulose (PPY-CMC) conducting polymer composite films on indium tin oxide (ITO) glass electrode from an aqueous solution containing pyrrole monomer, ptoluenesulfonate electrolyte and carboxymethylcellulose insulating polymer is reported. The characterization by Fourier transform infrared spectroscopy (FT-IR) shows that carboxymethylcellulose (CMC) has been successfully incorporated into polypyrrole structure forming PPY-CMC polymer composite films. The conductivity of the prepared composite films was found to increase with increaseing CMC concentration in pyrrole solution. The optical microscopic results show the influence of CMC concentration in the pyrrole solution over the morphological changes of the prepared films. The dynamic mechanical analysis (DMA) on the prepared PPY-CMC film reveals the higher plastic property of the PPY-CMC composite film.

  20. Transport studies of conducting, semiconducting and photoconducting star polymers

    Science.gov (United States)

    Ferguson, John Baker

    Star polymers are studied for their transport properties in the highly conducting state doped with NOPF6 and iodine, the undoped semiconducting state and the photoconducting state. Doped star polymers exhibit variable range hopping of charge carriers. Transport dimensionality and conductivity depend intricately on the processing conditions for doping and casting films. The highest conducting diffusion doped film (room temperature conductivity 50 S/cm) exhibits 2-dimensional variable range for all doping levels. Polymers doped in solution, then cast to form films have 1.4 dimensional variable range hopping for the highest conducting samples with 10 S/cm at room temperature. The hopping dimensionality varies as the conductivity decreases. The doped star polymers remain on the insulator side of the insulator metal transition with localized carriers as revealed with Kramer-Kronig analysis. Optical and near infrared absorbance and photoluminescence reveal the core of the star polymers exist in a solid state solution of the arms with similar absorbance and luminescence for both solution and films. The arms retain the optical properties of their linear analogs indicating the core and arms do not interact quantum mechanically to produce a new state. Excitons created by absorption in the wider band gap cores rapidly migrate to the arms. Photoconductive time of flight mobility measurements reveal an almost field independent mobility at room temperature. This is due to a unique cancellation of on diagonal and off diagonal disorder in the Bassler disorder formalism. The cores introduce heterogeneous regions with a net lower mobility predicted by correlated disorder models. Space charge limited current reveals trap densities several orders of magnitude higher than the carrier density. Photovoltaic performance of star polymer and fullerene blend devices with both 20 nm and 100 nm thick layers are investigated. The thin devices have low open circuit voltages due to space charge

  1. Wearable Keyboard Using Conducting Polymer Electrodes on Textiles.

    Science.gov (United States)

    Takamatsu, Seiichi; Lonjaret, Thomas; Ismailova, Esma; Masuda, Atsuji; Itoh, Toshihiro; Malliaras, George G

    2016-06-01

    A wearable keyboard is demonstrated in which conducting polymer electrodes on a knitted textile sense tactile input as changes in capacitance. The use of a knitted textile as a substrate endows stretchability and compatibility to large-area formats, paving the way for a new type of wearable human-machine interface.

  2. Physical properties of Li ion conducting polyphosphazene based polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, S.; Zawodzinski, T.; Hermes, R.; Davey, J.; Dai, Hongli

    1996-12-31

    We report a systematic study of the transport properties and the underlying physical chemistry of some polyphosphazene (PPhz)-based polymer electrolytes. We synthesized MEEP and variants which employed mixed combinations of different length oxyethylene side-chains. We compare the conductivity and ion-ion interactions in polymer electrolytes obtained with lithium triflate and lithium bis(trifluoromethanesulfonyl)imide (TFSI) salts added to the polymer. The combination of the lithium imide salt and MEEP yields a maximum conductivity of 8 x 10{sup -5} {Omega}{sup -1} cm{sup -1} at room temperature at a salt loading of 8 monomers per lithium. In one of the mixed side-chain variations, a maximum conductivity of 2 x 10{sup -4} {Omega}{sup -1} cm{sup -1} was measured at the same molar ratio. Raman spectral analysis shows some ion aggregation and some polymer - ion interactions in the PPhz-LiTFSI case but much less than observed with Li CF{sub 3}SO{sub 3}. A sharp increase in the Tg as salt is added corresponds to concentrations above which the conductivity significantly decreases and ion associations appear.

  3. Functionalised hybrid materials of conducting polymers with individual wool fibers.

    Science.gov (United States)

    Kelly, Fern M; Johnston, James H; Borrmann, Thomas; Richardson, Michael J

    2008-04-01

    Composites of natural protein materials, such as merino wool, with the conducting polymers polypyrrole (PPy) and polyaniline (PAn) have been successfully synthesised. In doing so, hybrid materials have been produced in which the mechanical strength and flexibility of the fibers is retained whilst also incorporating the desired chemical and electrical properties of the polymer. Scanning electron microscopy shows PPy coatings to comprise individual polymer spheres, approximately 100 to 150 nm in diameter. The average size of the polymer spheres of PAn was observed to be approximately 50 to 100 nm in diameter. These spheres fuse together in a continuous sheet to coat the fibers in their entirety. The reduction of silver ions to silver metal nanoparticles onto the redox active polymer surface has also been successful and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterisation of such products has been undertaken through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electrical conductivity, cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and the testing of their anti-microbial activity.

  4. Shear induced electrical behaviour of conductive polymer composites

    OpenAIRE

    Stary, Zdenek; Krückel, Johannes; Schubert, Dirk W.

    2013-01-01

    The time-dependent electrical resistance of polymethylmethacrylate containing carbon black was measured under oscillatory shear in the molten state. The electrical signal was oscillating exactly at the doubled frequency of the oscillatory shear deformation. Moreover, the experimental results gave a hint to the development of conductive structures in polymer melts under shear deformation. It was shown that the flow induced destruction of conductive paths dominates over the flow induced build-u...

  5. MEASUREMENT METHOD AND PHYSICAL MODEL OF VSC CONDUCTIVITY AND ITS APPLICATIONS IN CONDUCTING POLYMERS

    Institute of Scientific and Technical Information of China (English)

    WAN Meixiang

    1989-01-01

    Method of VSC (Voltage Shorted Compaction ) can be used to determine the intrinsic temperature dependence of conductivity of polycrystalline compaction .The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail.

  6. New secondary batteries utilizing electronically conductive polymer cathodes

    Science.gov (United States)

    Martin, Charles R.; White, Ralph E.

    1989-01-01

    The objectives of this project are to characterize the transport properties in electronically conductive polymers and to assess the utility of these films as cathodes in lithium/polymer secondary batteries. During this research period, progress has been made in a literature survey of the historical background, methods of preparation, the physical and chemical properties, and potential technological applications of polythiophene. Progress has also been made in the characterization of polypyrrole flat films and fibrillar films. Cyclic voltammetry and potential step chronocoulometry were used to gain information on peak currents and potentials switching reaction rates, charge capacity, and charge retention. Battery charge/discharge studies were also performed.

  7. COMMUNICATION: Electrochemical polymerization of conducting polymers in living neural tissue

    Science.gov (United States)

    Richardson-Burns, Sarah M.; Hendricks, Jeffrey L.; Martin, David C.

    2007-06-01

    A number of biomedical devices require extended electrical communication with surrounding tissue. Significant improvements in device performance would be achieved if it were possible to maintain communication with target cells despite the reactive, insulating scar tissue that forms at the device-tissue interface. Here, we report that the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) can be polymerized directly within living neural tissue resulting in an electrically conductive network that is integrated within the tissue. Nano and microscale PEDOT filaments extend out from electrode sites, presumably forming within extracellular spaces. The cloud of PEDOT filaments penetrates out into the tissue far enough that it should be possible to bypass fibrous scar tissue and contact surrounding healthy neurons. These electrically functional, diffuse conducting polymer networks grown directly within tissue signify a new paradigm for creating soft, low impedance implantable electrodes.

  8. Electropolymerization on wireless electrodes towards conducting polymer microfibre networks

    Science.gov (United States)

    Koizumi, Yuki; Shida, Naoki; Ohira, Masato; Nishiyama, Hiroki; Tomita, Ikuyoshi; Inagi, Shinsuke

    2016-01-01

    Conducting polymers can be easily obtained by electrochemical oxidation of aromatic monomers on an electrode surface as a film state. To prepare conducting polymer fibres by electropolymerization, templates such as porous membranes are necessary in the conventional methods. Here we report the electropolymerization of 3,4-ethylenedioxythiophene and its derivatives by alternating current (AC)-bipolar electrolysis. Poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives were found to propagate as a fibre form from the ends of Au wires used as bipolar electrodes (BPEs) parallel to an external electric field, without the use of templates. The effects of applied frequency and of the solvent on the morphology, growth rate and degree of branching of these PEDOT fibres were investigated. In addition, a chain-growth model for the formation of conductive material networks was also demonstrated.

  9. Electrically conductive, optically transparent polymer/carbon nanotube composites

    Science.gov (United States)

    Connell, John W. (Inventor); Smith, Jr., Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  10. Synthesis of polymer nanostructures with conductance switching properties

    Energy Technology Data Exchange (ETDEWEB)

    Su, Kai; Nuraje, Nurxat; Zhang, Lingzhi; Matsui, Hiroshi; Yang, Nan Loh

    2015-03-03

    The present invention is directed to crystalline organic polymer nanoparticles comprising a conductive organic polymer; wherein the crystalline organic polymer nanoparticles have a size of from 10 nm to 200 nm and exhibits two current-voltage states: (1) a high resistance current-voltage state, and (2) a low resistance current-voltage state, wherein when a first positive threshold voltage (V.sub.th1) or higher positive voltage, or a second negative threshold voltage (V.sub.th2) or higher negative voltage is applied to the nanoparticle, the nanoparticle exhibits the low-resistance current-voltage state, and when a voltage less positive than the first positive threshold voltage or a voltage less negative than the second negative threshold voltage is applied to the nanoparticle, the nanoparticle exhibits the high-resistance current-voltage state. The present invention is also directed methods of manufacturing the nanoparticles using novel interfacial oxidative polymerization techniques.

  11. Ultrafast terahertz conductivity and transient optical absorption spectroscopy of silicon nanocrystal thin films

    DEFF Research Database (Denmark)

    Titova, Lyubov V.; Harthy, Rahma Al; Cooke, David;

    We use time-resolved THz spectroscopy and transient optical absorption spectroscopy as two complementary techniques to study ultrafast carrier dynamics in silicon nanocrystal thin films. We find that the photoconductive dynamics in these materials is dominated by interface trapping, and we observe...... several different relaxation mechanisms for photoexcited carriers...

  12. Mechanistic study of silver nanoparticle formation on conducting polymer surfaces.

    Science.gov (United States)

    Mack, Nathan H; Bailey, James A; Doorn, Stephen K; Chen, Chien-An; Gau, Han-Mou; Xu, Ping; Williams, Darrick J; Akhadov, Elshan A; Wang, Hsing-Lin

    2011-04-19

    Conducting polymer (polyaniline) sheets are shown to be active substrates to promote the growth of nanostructured silver thin films with highly tunable morphologies. Using the spontaneous electroless deposition of silver, we show that a range of nanostructured metallic features can be controllably and reproducibly formed over large surface areas. The structural morphology of the resulting metal-polymer nanocomposite is demonstrated to be sensitive to experimental parameters such as ion concentration, temperature, and polymer processing and can range from densely packed oblate nanosheets to bulk crystalline metals. The deposition mechanisms are explained using a diffusion-limited aggregation (DLA) model to describe the semi-fractal-like growth of the metal nanostructures. We find these composite films to exhibit strong surface-enhanced Raman (SERS) activity, and the nanostructured features are optimized with respect to SERS activity using a self-assembled monolayer of mercapto-benzoic acid as a model Raman reporter. SERS enhancements are estimated to be on the order of 10(7). Through micro-Raman SERS mapping, these materials are shown to exhibit uniform SERS responses over macroscopic areas. These metal-polymer nanocomposites benefit from the underlying polymer's processability to yield SERS-active materials of almost limitless shape and size and show significant promise for future SERS-based sensing and detection schemes. PMID:21434643

  13. Photovoltaic Cells with TiO2 Nanocrystals and Conjugated Polymer Composites

    Institute of Scientific and Technical Information of China (English)

    YU Huang-Zhong; LIU Jin-Cheng; PENG Jun-Biao

    2008-01-01

    @@ Various compositional photovoltaic cells based on the blend of poly(3-hexylthiophene) (P3HT) as donors and TiO2 nanoerystals as acceptors are fabricated and investigated. It is demonstrated that the blend ratio of P3HT and TiO2 nanocrystals could greatly influence the performance of the photovoltaic cells. The maximum of 0.411% in power conversion efficiency under AM 1.5, 100mW//cm2, and 44.4% of fill factor are obtained in the solar cell with the blend weight ratio 1:1 of P3HT and TiO2 nanocrystals. The function of nanocrystal composition is discussed in terms of the results of photoluminescence spectroscopy, atomic force microscopy, transmission electron microscopy, and charge transport Ⅰ-Ⅴ curve.

  14. Interdiffusion and Spinodal Decomposition in Electrically Conducting Polymer Blends

    Directory of Open Access Journals (Sweden)

    Antti Takala

    2015-08-01

    Full Text Available The impact of phase morphology in electrically conducting polymer composites has become essential for the efficiency of the various functional applications, in which the continuity of the electroactive paths in multicomponent systems is essential. For instance in bulk heterojunction organic solar cells, where the light-induced electron transfer through photon absorption creating excitons (electron-hole pairs, the control of diffusion of the spatially localized excitons and their dissociation at the interface and the effective collection of holes and electrons, all depend on the surface area, domain sizes, and connectivity in these organic semiconductor blends. We have used a model semiconductor polymer blend with defined miscibility to investigate the phase separation kinetics and the formation of connected pathways. Temperature jump experiments were applied from a miscible region of semiconducting poly(alkylthiophene (PAT blends with ethylenevinylacetate-elastomers (EVA and the kinetics at the early stages of phase separation were evaluated in order to establish bicontinuous phase morphology via spinodal decomposition. The diffusion in the blend was followed by two methods: first during a miscible phase separating into two phases: from the measurement of the spinodal decomposition. Secondly the diffusion was measured by monitoring the interdiffusion of PAT film into the EVA film at elected temperatures and eventually compared the temperature dependent diffusion characteristics. With this first quantitative evaluation of the spinodal decomposition as well as the interdiffusion in conducting polymer blends, we show that a systematic control of the phase separation kinetics in a polymer blend with one of the components being electrically conducting polymer can be used to optimize the morphology.

  15. Stably Doped Conducting Polymer Nanoshells by Surface Initiated Polymerization.

    Science.gov (United States)

    Li, Junwei; Yoon, Soon Joon; Hsieh, Bao-Yu; Tai, Wanyi; O'Donnell, Matthew; Gao, Xiaohu

    2015-12-01

    Despite broad applications ranging from electronics to biomedical sensing and imaging, a long-standing problem of conducting polymers is the poor resistance to dedoping, which directly affects their signature electrical and optical properties. This problem is particularly significant for biomedical uses because of fast leaching of dopant ions in physiological environments. Here, we describe a new approach to engineer multimodal core-shell nanoparticles with a stably doped conductive polymer shell in biological environments. It was achieved by making a densely packed polymer brush rather than changing its molecular structure. Polyaniline (PANI) was used as a model compound due to its concentrated near-infrared (NIR) absorption. It was grafted onto a magnetic nanoparticle via a polydopamine intermediate layer. Remarkably, at pH 7 its conductivity is ca. 2000× higher than conventional PANI nanoshells. Similarly, its NIR absorption is enhanced by 2 orders of magnitude, ideal for photothermal imaging and therapy. Another surprising finding is its nonfouling property, even outperforming polyethylene glycol. This platform technology is also expected to open exciting opportunities in engineering stable conductive materials for electronics, imaging, and sensing.

  16. Conducting polymer/carbon nanocoil composite electrodes for efficient supercapacitors

    KAUST Repository

    Baby, Rakhi Raghavan

    2012-01-01

    Herein, we report for the first time, conducting polymer (polyaniline (PANI) and polypyrrole (PPY)) coated carbon nanocoils (CNCs) as efficient binder-free electrode materials for supercapacitors. CNCs act as a perfect backbone for the uniform distribution of the conducting polymers in the composites. In two electrode configuration, the samples exhibited high specific capacitance with the values reaching up to 360 and 202 F g -1 for PANI/CNCs and PPY/CNCs respectively. The values obtained for specific capacitance and maximum storage energy per unit mass of the composites were found to be comparable to one of the best reported values for polymer coated multi-walled carbon nanotubes. In addition, the fabricated PANI/CNC based supercapacitors exhibited a high value of 44.61 Wh kg -1 for maximum storage energy per unit mass. Although the devices exhibit an initial capacitance loss due to the instability of the polymer, the specific capacitance stabilizes at a fixed value after 500 charge-discharge cycles. © 2012 The Royal Society of Chemistry.

  17. Carbon Nanotubes - Polymer Composites with Enhanced Conductivity using Functionalized Nanotubes

    Science.gov (United States)

    Ramasubramaniam, Rajagopal; Chen, Jian; Gupta, Rishi

    2003-03-01

    Individual carbon nanotubes show superior electrical, mechanical and thermal properties [1]. Composite materials using carbon nanotubes as fillers are predicted to show similar superior properties. However, realization of such composites has been plagued by poor dispersion of carbon nanotubes in solvents and in polymer matrices. We have developed a method to homogenously disperse carbon nanotubes in polymer matrices using functionalized nanotubes [2]. Thin films of functionalized single walled nanotubes (SWNT) - polystyrene composites and functionalized SWNT - polycarbonate composites were prepared using solution evaporation and spin coating. Both of the composites show several orders of magnitude increase in conductivity for less than 1 wt thresholds of the composites are less than 0.2 wt nanotubes. We attribute the enhanced conduction to the superior dispersion of the functionalized nanotubes in the polymer matrix and to the reduced nanotube waviness resulting from the rigid backbone of the conjugated polymer. References: [1]. R. H. Baughman, A. A. Zakhidov and W. A. de Heer, Science v297, p787 (2002); [2]. J. Chen, H. Liu, W. A. Weimer, M. D. Halls, D. H. Waldeck and G. C. Walker, J. Am. Chem. Soc. v124, p9034 (2002).

  18. Experimental investigations on a proton conducting nanocomposite polymer electrolyte

    International Nuclear Information System (INIS)

    A new proton conducting nanocomposite polymer electrolyte (NCPE) comprising polyethylene oxide (PEO)-NH4HSO4 salt complex dispersed with nanosized SiO2 particles has been investigated. The NCPE films have been formed following the usual solution cast method. The results of various studies based on scanning electron microscopy, x-ray diffraction, differential scanning calorimetry, Fourier transform infra-red spectroscopy as well as some basic ionic transport parameters, namely conductivity, and ionic transference number, are presented and discussed. SiO2 concentration dependent conductivity measurements have been carried out on the NCPE films at room temperature. This study revealed the existence of two conductivity maxima at SiO2 concentrations ∼3 and 12 wt% which have been attributed to two percolation thresholds in the composite polymer electrolyte phase. An optimum value of conductivity (σ ∼ 6.2 x 10-5 S cm-1 at 27 0C) was achieved for the NCPE film with 3 wt% SiO2 dispersion. This has been referred to as optimum conducting composition. The temperature dependence of conductivity exhibited an Arrhenius-type thermally activated behaviour both below and above the semicrystalline-amorphous phase transition temperature of PEO

  19. Sub-Micrometer Size Structure Fabrication Using a Conductive Polymer

    Directory of Open Access Journals (Sweden)

    Junji Sone

    2014-12-01

    Full Text Available Stereolithography that uses a femtosecond laser was employed as a method for multiphoton-sensitized polymerization. We studied the stereolithography method, which produces duplicate solid shapes corresponding to the trajectory of the laser focus point and can be used to build a three-dimensional (3D structure using a conductive polymer. To achieve this, we first considered a suitable polymerization condition for line stereolithography. However, this introduced a problem of irregular polymerization. To overcome this, we constructed a support in the polymerized part using a protein material. This method can stabilize polymerization, but it is not suited for building 3D shapes. Therefore, we considered whether heat accumulation causes the irregular polymerization; consequently, the reduction method of the repetition rate of the femtosecond laser was used to reduce the heating process. This method enabled stabilization and building of a 3D shape using photo-polymerization of a conductive polymer.

  20. Electrofragmentation modeling of conductive coatings on polymer substrates

    OpenAIRE

    Leterrier, Yves; Pinyol, Albert; Rougier, Luc; Waller, Judith H.; Månson, Jan-Anders E.

    2009-01-01

    Damage occurring under tensile loading and the resulting increase of electrical resistance of indium-doped tin oxide and amorphous graphite coatings on various polymer substrates are investigated, using an electro-fragmentation method in situ in an optical microscope. The electrical resistance is modeled as a function of damage state assuming that the resistance of coating cracks is proportional to their opening, and that there exists a conducting path of constant thickness at the coating/sub...

  1. Electroless deposition of conducting polymers using the scanning electrochemical microscope

    Energy Technology Data Exchange (ETDEWEB)

    Borgwarth, K.; Ricken, C.; Heinze, J. [Freiburg Univ. (Germany). Inst. fuer Physikalische Chemie; Rohde, N.; Hallensleben, M.L.; Mandler, D.

    1999-10-01

    Micropatterning of organic substances using scanning electrochemical microscopy (SECM) is presented as a versatile, reproducible method for obtaining patterned materials of mesoscopic resolution-between that of conventional lithography and scanning tunneling microscopy or atomic force microscopy. In this technique, conducting polymer is electrolessly deposited on different substrates. It is reported that both flat layers and sets of thin needles protruding from the surface may be formed simply by varying the nature of the redox mediator. (orig.)

  2. Sub-Micrometer Size Structure Fabrication Using a Conductive Polymer

    OpenAIRE

    Junji Sone; Katsumi Yamada; Akihisa Asami; Jun De Chen

    2014-01-01

    Stereolithography that uses a femtosecond laser was employed as a method for multiphoton-sensitized polymerization. We studied the stereolithography method, which produces duplicate solid shapes corresponding to the trajectory of the laser focus point and can be used to build a three-dimensional (3D) structure using a conductive polymer. To achieve this, we first considered a suitable polymerization condition for line stereolithography. However, this introduced a problem of irregular polymeri...

  3. Conductive Polymer Combined Silk Fiber Bundle for Bioelectrical Signal Recording

    OpenAIRE

    Shingo Tsukada; Hiroshi Nakashima; Keiichi Torimitsu

    2012-01-01

    Electrode materials for recording biomedical signals, such as electrocardiography (ECG), electroencephalography (EEG) and evoked potentials data, are expected to be soft, hydrophilic and electroconductive to minimize the stress imposed on living tissue, especially during long-term monitoring. We have developed and characterized string-shaped electrodes made from conductive polymer with silk fiber bundles (thread), which offer a new biocompatible stress free interface with living tissue in bot...

  4. A practical multilayered conducting polymer actuator with scalable work output

    International Nuclear Information System (INIS)

    Household assistance robots are expected to become more prominent in the future and will require inherently safe design. Conducting polymer-based artificial muscle actuators are one potential option for achieving this safety, as they are flexible, lightweight and can be driven using low input voltages, unlike electromagnetic motors; however, practical implementation also requires a scalable structure and stability in air. In this paper we propose and practically implement a multilayer conducting polymer actuator which could achieve these targets using polypyrrole film and ionic liquid-soaked separators. The practical work density of a nine-layer multilayer actuator was 1.4 kJ m−3 at 0.5 Hz, when the volumes of the electrolyte and counter electrodes were included, which approaches the performance of mammalian muscle. To achieve air stability, we analyzed the effect of air-stable ionic liquid gels on actuator displacement using finite element simulation and it was found that the majority of strain could be retained when the elastic modulus of the gel was kept below 3 kPa. As a result of this work, we have shown that multilayered conducting polymer actuators are a feasible idea for household robotics, as they provide a substantial practical work density in a compact structure and can be easily scaled as required

  5. Microscopic mechanism of reinforcement and conductivity in polymer nanocomposite materials

    Science.gov (United States)

    Chang, Tae-Eun

    Modification of polymers by adding various nano-particles is an important method to obtain effective enhancement of materials properties. Within this class of materials, carbon nanotubes (CNT) are among the most studied materials for polymer reinforcement due to their extraordinary mechanical properties, superior thermal and electronic properties, and high aspect ratio. However, to unlock the potential of CNTs for applications, CNTs must be well dispersed in a polymer matrix and the microscopic mechanism of polymer reinforcement by CNTs must be understood. In this study, single-wall carbon nanotube (SWNT) composites with polypropylene (PP)-SWNT and polystyrene (PS)-SWNT were prepared and analyzed. Microscopic study of the mechanism of reinforcement and conductivity by SWNT included Raman spectroscopy, wide-angle X-ray diffraction (WAXD) and dielectric measurement. For PP-SWNT composites, tensile tests show a three times increase in the Young's modulus with addition of only 1 wt% SWNT, and much diminished increase of modulus with further increase in SWNT concentration. For PS-SWNT composites, well-dispersed SWNT/PS composite has been produced, using initial annealing of SWNT and optimum sonication conditions. The studies on the tangential mode in the Raman spectra and TEM indicated well-dispersed SWNTs in a PS matrix. We show that conductivity appears in composites already at very low concentrations, hinting at the formation of a 'percolative' network even below 0.5% of SWNT. The Raman studies for both composites show good transfer of the applied stress from the polymer matrices to SWNTs. However, no significant improvement of mechanical property is observed for PS-SWNT composites. The reason for only a slight increase of mechanical property remains unknown.

  6. EFFECTS OF TRITIUM GAS EXPOSURE ON ELECTRICALLY CONDUCTING POLYMERS

    Energy Technology Data Exchange (ETDEWEB)

    Kane, M.; Clark, E.; Lascola, R.

    2009-12-16

    Effects of beta (tritium) and gamma irradiation on the surface electrical conductivity of two types of conducting polymer films are documented to determine their potential use as a sensing and surveillance device for the tritium facility. It was shown that surface conductivity was significantly reduced by irradiation with both gamma and tritium gas. In order to compare the results from the two radiation sources, an approximate dose equivalence was calculated. The materials were also sensitive to small radiation doses (<10{sup 5} rad), showing that there is a measurable response to relatively small total doses of tritium gas. Spectroscopy was also used to confirm the mechanism by which this sensing device would operate in order to calibrate this sensor for potential use. It was determined that one material (polyaniline) was very sensitive to oxidation while the other material (PEDOT-PSS) was not. However, polyaniline provided the best response as a sensing material, and it is suggested that an oxygen-impermeable, radiation-transparent coating be applied to this material for future device prototype fabrication. A great deal of interest has developed in recent years in the area of conducting polymers due to the high levels of conductivity that can be achieved, some comparable to that of metals [Gerard 2002]. Additionally, the desirable physical and chemical properties of a polymer are retained and can be exploited for various applications, including light emitting diodes (LED), anti-static packaging, electronic coatings, and sensors. The electron transfer mechanism is generally accepted as one of electron 'hopping' through delocalized electrons in the conjugated backbone, although other mechanisms have been proposed based on the type of polymer and dopant [Inzelt 2000, Gerard 2002]. The conducting polymer polyaniline (PANi) is of particular interest because there are extensive studies on the modulation of the conductivity by changing either the oxidation

  7. Conductivity Studies of the Plasticized-Poly(methylmethacrylate) Polymer Electrolytes

    Institute of Scientific and Technical Information of China (English)

    A.Ahmad; Z.Osman

    2007-01-01

    1 Results In this work,five systems of polymethylmethacrylate (PMMA)-based polymer electrolytes films have been prepared by the solution casting technique.The five systems are the (PMMA-EC) system,the (PMMA + PC) system,the (PMMA+LiCF3SO3) system,the ([PMMA+EC]+LiCF3SO3) system and the ([PMMA+PC]+LiCF3SO3) system.The conductivity for each system is characterized using impedance spectroscopy.The conductivity of the pure PMMA,the (PMMA+EC) system and the (PMMA+PC) system at room temperature is 2.37×10-9,3...

  8. Better Proton-Conducting Polymers for Fuel-Cell Membranes

    Science.gov (United States)

    Narayan, Sri; Reddy, Prakash

    2012-01-01

    Polyoxyphenylene triazole sulfonic acid has been proposed as a basis for development of improved proton-conducting polymeric materials for solid-electrolyte membranes in hydrogen/air fuel cells. Heretofore, the proton-conducting membrane materials of choice have been exemplified by a family of perfluorosulfonic acid-based polymers (Nafion7 or equivalent). These materials are suitable for operation in the temperature of 75 to 85 C, but in order to reduce the sizes and/or increase the energy-conversion efficiencies of fuel-cell systems, it would be desirable to increase temperatures to as high as 120 C for transportation applications, and to as high as 180 C for stationary applications. However, at 120 C and at relative humidity values below 50 percent, the loss of water from perfluorosulfonic acid-based polymer membranes results in fuel-cell power densities too low to be of practical value. Therefore, membrane electrolyte materials that have usefully high proton conductivity in the temperature range of 180 C at low relative humidity and that do not rely on water for proton conduction at 180 C would be desirable. The proposed polyoxyphenylene triazole sulfonic acid-based materials have been conjectured to have these desirable properties. These materials would be free of volatile or mobile acid constituents. The generic molecular structure of these materials is intended to exploit the fact, demonstrated in previous research, that materials that contain ionizable acid and base groups covalently attached to thermally stable polymer backbones exhibit proton conduction even in the anhydrous state.

  9. Conductivity of oriented bis-azo polymer films

    DEFF Research Database (Denmark)

    Apitz, D.; Bertram, R.P.; Benter, N.;

    2006-01-01

    The conductivity properties of electro-optic photoaddressable, dense bis-ozo chromophore polymer films are investigated by using samples corona poled at various temperatures. A dielectric spectrometer is applied to measure the frequency dependence of the conductivity at different temperatures...... before and after heating the material to above the glass transition temperature. The results show that the orientation of the chromophores changes the charge-carrier mobility. Ionic conductivity dominates in a more disordered configuration of the material, while the competing process of hole hopping...... takes over as a transition to a liquid-crystalline phase occurs when the material is heated to much higher than the gloss transition temperature. Such micro-crystallization strongly enhances the conductivity....

  10. New transparent conductive metal based on polymer composite

    Energy Technology Data Exchange (ETDEWEB)

    Keshavarz Hedayati, Mehdi; Jamali, Mohammad [Nanochemistry and Nanoengineering, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University, Kiel (Germany); Strunkus, Thomas; Zaporochentko, Vladimir; Faupel, Franz [Multicomponent Materials, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University, Kiel (Germany); Elbahri, Mady [Nanochemistry and Nanoengineering, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University, Kiel (Germany); Helmholtz-Zentrum Geesthacht GmbH, Institute of Polymer Research, Nanochemistry and Nanoengineering (Germany)

    2011-07-01

    Currently great efforts are made to develop new kind of transparent conductors (TCs) to replace ITO. In this regard different materials and composites have been proposed and studied including conductive polymers, carbon nanotubes (CNTs), metal grids, and random networks of metallic nanowires. But so far none of them could be used as a replacing material, since either they are either fragile and brittle or their electrical conductivity is below the typical ITO. Thin metallic films due to their high electrical conductivity could be one of the best replacing materials for ITO, however their poor transparency makes their application as TCs limited. Here we design and fabricate a new polymeric composite coating which enhances the transparency of the thin metal film up to 100% relative to the initial value while having a high electrical conductivity of typical metals. Therefore our proposed device has a great potential to be used as new transparent conductor.

  11. Self-assembly of CdTe nanocrystals at the water/oil interface by amphiphilic hyperbranched polymers

    International Nuclear Information System (INIS)

    A general strategy for realizing the self-assembly of aqueous CdTe nanocrystals (NCs) at the water/oil interface by means of an amphiphilic core-shell hyperbranched polymer has been proposed. Aqueous CdTe NCs were firstly transferred into the chloroform phase in the presence of palmityl chloride functionalized hyperbranched poly(amidoamine) (HPAMAM-PC), and then self-assembled at the water/chloroform interface by decreasing the pH value of the aqueous phase or introducing α-CDs to the aqueous phase. The resulting CdTe/HPAMAM-PC self-assembly film was characterized by fluorescence microscopy, UV-vis, PL, TEM, EDS, FT-IR, DSC and TGA.

  12. Conducting polymer nanofibers for high sensitivity detection of chemical analytes.

    Science.gov (United States)

    Kumar, Abhishek; Leshchiner, Ignaty; Nagarajan, Subhalakshmi; Nagarajan, Ramaswamy; Kumar, Jayant

    2008-03-01

    Possessing large surface area materials is vital for high sensitivity detection of analyte. We report a novel, inexpensive and simple technique to make high surface area sensing interfaces using electrospinning. Conducting polymers (CP) nanotubes were made by electrospinning a solution of a catalyst (ferric tosylate) along with poly (lactic acid), which is an environment friendly biodegradable polymer. Further vapor deposition polymerization of the monomer ethylenedioxy thiophene (EDOT) on the nanofiber surface yielded poly (EDOT) covered fibers. X-ray photo electron spectroscopy (XPS) study reveals the presence of PEDOT predominantly on the surface of nanofibers. Conducting nanotubes had been received by dissolving the polymer in the fiber core. By a similar technique we had covalently incorporated fluorescent dyes on the nanofiber surface. The materials obtained show promise as efficient sensing elements. UV-Vis characterization confirms the formation of PEDOT nanotubes and incorporation of chromophores on the fiber surface. The morphological characterization was carried out using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

  13. Thermal conductivity of polymer composites with oriented boron nitride

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hong Jun; Eoh, Young Jun [Department of Materials Engineering, Kyonggi University, Suwon (Korea, Republic of); Park, Sung Dae [Electronic Materials and Device Research Center, Korea Electronics Technology Institute, Seongnam (Korea, Republic of); Kim, Eung Soo, E-mail: eskim@kyonggi.ac.kr [Department of Materials Engineering, Kyonggi University, Suwon (Korea, Republic of)

    2014-08-20

    Highlights: • Thermal conductivity depended on the orientation of BN in the polymer matrices. • Hexagonal boron nitride (BN) particles were treated by C{sub 27}H{sub 27}N{sub 3}O{sub 2} and C{sub 14}H{sub 6}O{sub 8}. • Amphiphilic-agent-treated BN particles are more easily oriented in the composite. • BN/PVA composites with C{sub 14}H{sub 6}O{sub 8}-treated BN showed the highest thermal conductivity. • Thermal conductivity of the composites was compared with several theoretical models. - Abstract: Thermal conductivity of boron nitride (BN) with polyvinyl alcohol (PVA) and/or polyvinyl butyral (PVB) was investigated as a function of the degree of BN orientation, the numbers of hydroxyl groups in the polymer matrices and the amphiphilic agents used. The composites with in-plane orientation of BN showed a higher thermal conductivity than the composites with out-of-plane orientation of BN due to the increase of thermal pathway. For a given BN content, the composites with in-plane orientation of BN/PVA showed higher thermal conductivity than the composites with in-plane orientation of BN/PVB. This result could be attributed to the improved degree of orientation of BN, caused by a larger number of hydroxyl groups being present. Those treated with C{sub 14}H{sub 6}O{sub 8} amphiphilic agent demonstrated a higher thermal conductivity than those treated by C{sub 27}H{sub 27}N{sub 3}O{sub 2}. The measured thermal conductivity of the composites was compared with that predicted by the several theoretical models.

  14. Thermal conductivity of polymer composites with oriented boron nitride

    International Nuclear Information System (INIS)

    Highlights: • Thermal conductivity depended on the orientation of BN in the polymer matrices. • Hexagonal boron nitride (BN) particles were treated by C27H27N3O2 and C14H6O8. • Amphiphilic-agent-treated BN particles are more easily oriented in the composite. • BN/PVA composites with C14H6O8-treated BN showed the highest thermal conductivity. • Thermal conductivity of the composites was compared with several theoretical models. - Abstract: Thermal conductivity of boron nitride (BN) with polyvinyl alcohol (PVA) and/or polyvinyl butyral (PVB) was investigated as a function of the degree of BN orientation, the numbers of hydroxyl groups in the polymer matrices and the amphiphilic agents used. The composites with in-plane orientation of BN showed a higher thermal conductivity than the composites with out-of-plane orientation of BN due to the increase of thermal pathway. For a given BN content, the composites with in-plane orientation of BN/PVA showed higher thermal conductivity than the composites with in-plane orientation of BN/PVB. This result could be attributed to the improved degree of orientation of BN, caused by a larger number of hydroxyl groups being present. Those treated with C14H6O8 amphiphilic agent demonstrated a higher thermal conductivity than those treated by C27H27N3O2. The measured thermal conductivity of the composites was compared with that predicted by the several theoretical models

  15. Training and shape retention in conducting polymer artificial muscles

    International Nuclear Information System (INIS)

    Electrochemomechanical deformation (ECMD) of the conducting polymer polyaniline film is studied to investigate the behaviour of actuation under tensile loads. The ECMD was induced by the strains due to the insertion of ionic species (cyclic strain) and a creep due to applied loads during the redox cycle. The cyclic strain was enhanced by the experience of high tensile loads, indicating a training effect. The training effect was explained by the enhanced electrochemical activity of the film. The creep was recovered by removal of the tensile load and several electrochemical cycles. This fact indicates that the creep results from the one-dimensional anisotropic deformation, and is retained (shape retention) by the ionic crosslink. The recovery of creep results from the elastic relaxation of the polymer conformation

  16. Preparation and Characterization of Lithium Ion Conducting Solid Polymer Electrolytes from Biodegradable Polymers Starch And PVA

    Directory of Open Access Journals (Sweden)

    B. Chatterjee,

    2015-06-01

    Full Text Available Solid Polymer electrolyte films have been prepared from Starch-Poly vinyl alcohol (PVA blend a well acknowledged biodegradable material. Solution cast technique was employed for the preparation of solid polymer electrolyte films added with Lithium Bromide (LiBr salt. X-ray diffraction (XRD studies of the prepared films portrayed the evolution of an amorphous structure with increasing content of salt which is an important factor that leads to the augmentation of conductivity. Electrochemical impedance spectroscopic analysis revealed noticeable ionic conductivity ~ 5x 10-3 S/cm for 20 wt% of salt at ambient conditions. Ionic conductivity showed an increasing trend with salt content at ambient conditions. Transference number measurements confirmed the ionic nature of the prepared solid polymer electrolyte films. Dielectric studies revealed a sharp increase in the number of charge carriers which contributed to enhancement in conductivity. Low values of activation energy extracted from temperature dependent conductivity measurements could be favorable for device applications. For the composition with highest conductivity a temperature independent relaxation mechanism was confirmed by electric modulus scaling.

  17. Ion conductivity and transport by porous coordination polymers and metal-organic frameworks.

    Science.gov (United States)

    Horike, Satoshi; Umeyama, Daiki; Kitagawa, Susumu

    2013-11-19

    (+)) and other ions can also be transported. If we can optimize the crystal structures, this could offer further improvements in terms of both conductivity and the working temperature range. Another useful characteristic of PCP/MOFs is their wide application to materials fabrication. We can easily prepare heterodomain crystal systems, such as core-shell or solid solution. Other anisotropic morphologies (thin film, nanocrystal, nanorod, etc.,) are also possible, with retention of the ion conductivity. The flexible nature also lets us design morphology-dependent ion-conduction behaviors that we cannot observe in the bulk state. We propose (1) multivalent ion and anion conductions with the aid of redox activity and defects in structures, (2) control of ion transport behavior by applying external stimuli, (3) anomalous conductivity at the hetero-solid-solid interface, and (4) unidirectional ion transport as in the ion channels in membrane proteins. In the future, scientists may use coordination polymers not only to achieve higher conductivity but also to control ion behavior, which will open new avenues in solid-state ionics.

  18. Conducting polymer actuators: From basic concepts to proprioceptive systems

    Science.gov (United States)

    Martinez Gil, Jose Gabriel

    Designers and engineers have been dreaming for decades of motors sensing, by themselves, working and surrounding conditions, as biological muscles do originating proprioception. Here bilayer full polymeric artificial muscles were checked up to very high cathodic potential limits (-2.5 V) in aqueous solution by cyclic voltammetry. The electrochemical driven exchange of ions from the conducting polymer film, and the concomitant Faradaic bending movement of the muscle, takes place in the full studied potential range. The presence of trapped counterion after deep reduction was corroborated by EDX determinations giving quite high electronic conductivity to the device. The large bending movement was used as a tool to quantify the amount of water exchanged per reaction unit (exchanged electron or ion). The potential evolutions of self-supported films of conducting polymers or conducting polymers (polypyrrole, polyaniline) coating different microfibers, during its oxidation/reduction senses working mechanical, thermal, chemical or electrical variables. The evolution of the muscle potential from electrochemical artificial muscles based on electroactive materials such as intrinsically conducting polymers and driven by constant currents senses, while working, any variation of the mechanical (trailed mass, obstacles, pressure, strain or stress), thermal or chemical conditions of work. One physically uniform artificial muscle includes one electrochemical motor and several sensors working simultaneously under the same driving reaction. Actuating (current and charge) and sensing (potential and energy) magnitudes are present, simultaneously, in the only two connecting wires and can be read by the computer at any time. From basic polymeric, mechanical and electrochemical principles a physicochemical equation describing artificial proprioception has been developed. It includes and describes, simultaneously, the evolution of the muscle potential during actuation as a function of the

  19. Thiophene in Conducting Polymers: Synthesis of Poly(thiophene)s and Other Conjugated Polymers Containing Thiophenes, for Application in Polymer Solar Cells

    DEFF Research Database (Denmark)

    Livi, Francesco; Carlé, Jon Eggert; Bundgaard, Eva

    2015-01-01

    Conducting polymers based on thiophene are described. The polymers include poly(thiophene) with and without side-chains and other conjugated polymers in general, based on thiophene. The synthesis and characteristics of the polymers are described along with the application of these as light-absorb...

  20. Utilization of novel bithiazole based conducting polymers in electrochromic applications

    International Nuclear Information System (INIS)

    In this paper we disclose the synthesis of a novel monomer (2,2′-di-pyrrol-1-yl-[4,4′]bithiazolyl, PyDBTH) and the optoelectronic properties of the resultant conducting polymers. PyDBTH was synthesized via the Clauson-Kaas reaction of 2,2′-diamino-4,4′-bithiazole with 2,5-dimethoxytetrahydrofuran in acetic acid which was characterized by 1H, 13C-NMR, FTIR and MS analyses. Homopolymerization and copolymerization (in the presence of 3,4-ethylenedioxythiophene) were achieved in a tetrabutylammonium hexafluorophosphate (TBAPF6) dichloromethane system. The electrochemical and electrochromic properties of the homopolymer and copolymers were examined by cyclic voltammetry, FTIR, spectroelectrochemistry and kinetic studies. Depending on the synthesis conditions, the bithiazole based polymers exhibited optical band gaps ranging from 2.60 to 1.75 eV and the copolymers displayed multichromism within a wide span of the visible spectrum. The copolymers revealed short switching times and useful optical contrast of 0.6 s and 54%, respectively. Due to its favorable electrochromic properties, utilization of bithiazole based polymers in electrochromic devices was also investigated. These devices exhibited low switching voltages and switching times with reasonable stability under atmospheric conditions. (paper)

  1. Conductive Polymer Porous Film with Tunable Wettability and Adhesion

    OpenAIRE

    Yuqi Teng; Yuqi Zhang; Liping Heng; Xiangfu Meng; Qiaowen Yang; Lei Jiang

    2015-01-01

    A conductive polymer porous film with tunable wettability and adhesion was fabricated by the chloroform solution of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyricacid-methyl-ester (PCBM) via the freeze drying method. The porous film could be obtained from the solution of 0.8 wt%, whose pore diameters ranged from 50 nm to 500 nm. The hydrophobic porous surface with a water contact angle (CA) of 144.7° could be transferred into a hydrophilic surface with CA of 25° by applying a vol...

  2. Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

    Science.gov (United States)

    Praveen, D.; Damle, Ramakrishna

    2016-05-01

    Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO4)2, NH4I etc., have already been tried in the past with some success. Also various nanoparticles like Al2O3, TiO2 etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.

  3. Calculation of thermal conductivity of polymer solutions in a wide range of temperatures and pressure

    International Nuclear Information System (INIS)

    Present article is devoted to calculation of thermal conductivity of polymer solutions in a wide range of temperatures and pressure. The dependence of thermal conductivity of polymers on temperature and pressure was studied. The dependence of thermal conductivity of polymers on molar mass was studied as well.

  4. Rechargeable aluminum batteries with conducting polymers as positive electrodes.

    Energy Technology Data Exchange (ETDEWEB)

    Hudak, Nicholas S.

    2013-12-01

    This report is a summary of research results from an Early Career LDRD project con-ducted from January 2012 to December 2013 at Sandia National Laboratories. Demonstrated here is the use of conducting polymers as active materials in the posi-tive electrodes of rechargeable aluminum-based batteries operating at room tempera-ture. The battery chemistry is based on chloroaluminate ionic liquid electrolytes, which allow reversible stripping and plating of aluminum metal at the negative elec-trode. Characterization of electrochemically synthesized polypyrrole films revealed doping of the polymers with chloroaluminate anions, which is a quasi-reversible reac-tion that facilitates battery cycling. Stable galvanostatic cycling of polypyrrole and polythiophene cells was demonstrated, with capacities at near-theoretical levels (30-100 mAh g-1) and coulombic efficiencies approaching 100%. The energy density of a sealed sandwich-type cell with polythiophene at the positive electrode was estimated as 44 Wh kg-1, which is competitive with state-of-the-art battery chemistries for grid-scale energy storage.

  5. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    KAUST Repository

    Kurra, Narendra

    2015-01-01

    In this study, we report the fabrication of solid-state asymmetric supercapacitors (ASCs) based on conducting polymer electrodes on a plastic substrate. Nanostructured conducting polymers of poly(3,4-ethylenedioxythiophene), PEDOT, and polyaniline (PANI) are deposited electrochemically over Au-coated polyethylene naphthalate (PEN) plastic substrates. Due to the electron donating nature of the oxygen groups in the PEDOT, reduction potentials are higher, allowing it to be used as a negative electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid state supercapacitors with PANI as a positive electrode while employing polyvinyl alcohol (PVA)/H2SO4 gel electrolyte. The ASCs exhibit a maximum power density of 2.8 W cm-3 at an energy density of 9 mW h cm-3, which is superior to the carbonaceous and metal oxide based ASC solid state devices. Furthermore, the tandem configuration of asymmetric supercapacitors is shown to be capable of powering a red light emitting diode for about 1 minute after charging for 10 seconds. © The Royal Society of Chemistry 2015.

  6. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    KAUST Repository

    Kurra, Narendra

    2015-02-16

    In this study, we report the fabrication of solid-state asymmetric supercapacitors (ASCs) based on conducting polymer electrodes on a plastic substrate. Nanostructured conducting polymers of poly(3,4-ethylenedioxythiophene), PEDOT, and polyaniline (PANI) are deposited electrochemically over Au-coated polyethylene naphthalate (PEN) plastic substrates. Due to the electron donating nature of the oxygen groups in the PEDOT, reduction potentials are higher, allowing it to be used as a negative electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid state supercapacitors with PANI as a positive electrode while employing polyvinyl alcohol (PVA)/H2SO4 gel electrolyte. The ASCs exhibit a maximum power density of 2.8 W cm−3 at an energy density of 9 mW h cm−3, which is superior to the carbonaceous and metal oxide based ASC solid state devices. Furthermore, the tandem configuration of asymmetric supercapacitors is shown to be capable of powering a red light emitting diode for about 1 minute after charging for 10 seconds.

  7. Electronically conductive polymer binder for lithium-ion battery electrode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gao; Xun, Shidi; Battaglia, Vincent S.; Zheng, Honghe; Wu, Mingyan

    2015-07-07

    A family of carboxylic acid groups containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. Triethyleneoxide side chains provide improved adhesion to materials such as, graphite, silicon, silicon alloy, tin, tin alloy. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  8. Multiscale Modeling of Thermal Conductivity of Polymer/Carbon Nanocomposites

    Science.gov (United States)

    Clancy, Thomas C.; Frankland, Sarah-Jane V.; Hinkley, Jeffrey A.; Gates, Thomas S.

    2010-01-01

    Molecular dynamics simulation was used to estimate the interfacial thermal (Kapitza) resistance between nanoparticles and amorphous and crystalline polymer matrices. Bulk thermal conductivities of the nanocomposites were then estimated using an established effective medium approach. To study functionalization, oligomeric ethylene-vinyl alcohol copolymers were chemically bonded to a single wall carbon nanotube. The results, in a poly(ethylene-vinyl acetate) matrix, are similar to those obtained previously for grafted linear hydrocarbon chains. To study the effect of noncovalent functionalization, two types of polyethylene matrices. -- aligned (extended-chain crystalline) vs. amorphous (random coils) were modeled. Both matrices produced the same interfacial thermal resistance values. Finally, functionalization of edges and faces of plate-like graphite nanoparticles was found to be only modestly effective in reducing the interfacial thermal resistance and improving the composite thermal conductivity

  9. Electronically conductive polymer binder for lithium-ion battery electrode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gao; Battaglia, Vincent S.; Park, Sang -Jae

    2015-10-06

    A family of carboxylic acid groups containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. Triethyleneoxide side chains provide improved adhesion to materials such as, graphite, silicon, silicon alloy, tin, tin alloy. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  10. Relationship between Polymer Dielectric Constant and Percolation Threshold in Conductive Poly(styrene)-Type Polymer and Carbon Black Composites

    OpenAIRE

    Mariana Castro Martínez; Susana Hernández López; Enrique Vigueras Santiago

    2015-01-01

    We study the effect of dielectric constant of some poly(styrene)-type polymer matrix on the percolation threshold in conductive polymer composites with carbon black (CB). We demonstrate that percolation threshold diminishes with an increment of the dielectric constant of polymer matrix. We chose polystyrene and other three polymers similar in structure and molecular weight but with different chemical nature. The corresponding dielectric constant and critical concentration, Xc, in volume frac...

  11. Comment on "Electrical Conductivity and Current-Voltage Characteristics of Individual Conducting Polymer PEDOT Nanowires"

    Institute of Scientific and Technical Information of China (English)

    P. Ohlckers; P. Pipinys

    2009-01-01

    @@ In "Electrical Conductivity and Current-Voltage Characteristics of Individual Conducting Polymer PEDOT Nanowires", Long et al.[1] reported the currentvoltage ( Ⅰ - Ⅴ) characteristics of individual poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires in the temperature range from 20 to 50K (Fig. 2(a)). The authors stated that at temperatures equal to 50 K and higher, the Ⅰ - Ⅴ curves were linear. With decreasing temperature the Ⅰ - Ⅴ curves gradually became nonlinear. The temperature behavior of Ⅰ - Ⅴ characteristics is not suitably explained.

  12. Formation of conductive polymers using nitrosyl ion as an oxidizing agent

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyoung-Shin; Jung, Yongju; Singh, Nikhilendra

    2016-06-07

    A method of forming a conductive polymer deposit on a substrate is disclosed. The method may include the steps of preparing a composition comprising monomers of the conductive polymer and a nitrosyl precursor, contacting the substrate with the composition so as to allow formation of nitrosyl ion on the exterior surface of the substrate, and allowing the monomer to polymerize into the conductive polymer, wherein the polymerization is initiated by the nitrosyl ion and the conductive polymer is deposited on the exterior surface of the substrate. The conductive polymer may be polypyrrole.

  13. Drastic modification of the piezoresistive behavior of polymer nanocomposites by using conductive polymer coatings

    KAUST Repository

    Ventura, Isaac Aguilar

    2015-07-21

    We obtained highly conductive nanocomposites by adding conductive polymer poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS)-coated carbon nanotubes (CNTs) to pristine insulating Polycarbonate. Because the PEDOT/PSS ensures efficient charge transfer both along and between the CNTs, we could attribute the improvement in electrical conductivity to coating. In addition to improving the electrical conductivity, the coating also modified the piezoresistive behavior of the nanocomposites compared to the material with pristine uncoated CNTs: whereas CNT/Polycarbonate samples exhibited a very strong piezoresistive effect, PEDOT/PSS-coated MWCNT/Polycarbonate samples exhibited very little piezoresistivity. We studied this change in piezoresistive behavior in detail by investigating various configurations of filler content. We investigated how this observation could be explained by changes in the microstructure and in the conduction mechanism in the interfacial regions between the nanofillers. Our study suggests that tailoring the piezoresistive response to specific application requirements is possible.

  14. Conductive polymer combined silk fiber bundle for bioelectrical signal recording.

    Directory of Open Access Journals (Sweden)

    Shingo Tsukada

    Full Text Available Electrode materials for recording biomedical signals, such as electrocardiography (ECG, electroencephalography (EEG and evoked potentials data, are expected to be soft, hydrophilic and electroconductive to minimize the stress imposed on living tissue, especially during long-term monitoring. We have developed and characterized string-shaped electrodes made from conductive polymer with silk fiber bundles (thread, which offer a new biocompatible stress free interface with living tissue in both wet and dry conditions.An electroconductive polyelectrolyte, poly(3,4-ethylenedioxythiophene-poly(styrenesulfonate (PEDOT-PSS was electrochemically combined with silk thread made from natural Bombyx mori. The polymer composite 280 µm thread exhibited a conductivity of 0.00117 S/cm (which corresponds to a DC resistance of 2.62 Mohm/cm. The addition of glycerol to the PEDOT-PSS silk thread improved the conductivity to 0.102 S/cm (20.6 kohm/cm. The wettability of PEDOT-PSS was controlled with glycerol, which improved its durability in water and washing cycles. The glycerol treated PEDOT-PSS silk thread showed a tensile strength of 1000 cN in both wet and dry states. Without using any electrolytes, pastes or solutions, the thread directly collects electrical signals from living tissue and transmits them through metal cables. ECG, EEG, and sensory evoked potential (SEP signals were recorded from experimental animals by using this thread placed on the skin. PEDOT-PSS silk glycerol composite thread offers a new class of biocompatible electrodes in the field of biomedical and health promotion that does not induce stress in the subjects.

  15. Decohesion Kinetics of PEDOT:PSS Conducting Polymer Films

    KAUST Repository

    Dupont, Stephanie R.

    2013-10-17

    The highly conductive polymer PEDOT:PSS is a widely used hole transport layer and transparent electrode in organic electronic devices. To date, the mechanical and fracture properties of this conductive polymer layer are not well understood. Notably, the decohesion rate of the PEDOT:PSS layer and its sensitivity to moist environments has not been reported, which is central in determining the lifetimes of organic electronic devices. Here, it is demonstrated that the decohesion rate is highly sensitive to the ambient moisture content, temperature, and mechanical stress. The kinetic mechanisms are elucidated using atomistic bond rupture models and the decohesion process is shown to be facilitated by a chemical reaction between water molecules from the environment and strained hydrogen bonds. Hydrogen bonds are the predominant bonding mechanism between individual PEDOT:PSS grains within the layer and cause a significant loss in cohesion when they are broken. Understanding the decohesion kinetics and mechanisms in these films is essential for the mechanical integrity of devices containing PEDOT:PSS layers and yields general guidelines for the design of more reliable organic electronic devices. Decohesion rate in PEDOT:PSS conducting films is studied under varied environmental conditions. The moisture content in the environment is the most important factor accelerating the decohesion in the PEDOT:PSS layer, which is detrimental for device reliability. The findings on the decohesion rate and mechanisms, elucidated by atomic kinetic models, are essential for the design of more reliable organic electronic devices containting PEDOT:PSS layers. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Conductivity of microfibrillar polymer-polymer composites with CNT-loaded microfibrils or compatibilizer: A comparative study

    OpenAIRE

    Fakirov, S.; S. M. Panamoottil; P. Potschke; R. J. T. Lin; Bhattacharyya, D

    2013-01-01

    Conductive polymer composites have wide ranging applications, but when they are produced by conventional melt blending, high conductive filler loadings are normally required, hindering their processability and reducing mechanical properties. In this study, two types of polymer-polymer composites were studied: i) microfibrillar composites (MFC) of polypropylene (PP) and 5 wt% carbon nanotube (CNT) loaded poly(butylene terephthalate) (PBT) as reinforcement, and ii) maleic anhydride-grafted poly...

  17. Amine-functionalized polypyrrole: Inherently cell adhesive conducting polymer.

    Science.gov (United States)

    Lee, Jae Y; Schmidt, Christine E

    2015-06-01

    Electrically conducting polymers (CPs) have been recognized as novel biomaterials that can electrically communicate with biological systems. For their tissue engineering applications, CPs have been modified to promote cell adhesion for improved interactions between biomaterials and cells/tissues. Conventional approaches to improve cell adhesion involve the surface modification of CPs with biomolecules, such as physical adsorption of cell adhesive proteins and polycationic polymers, or their chemical immobilization; however, these approaches require additional multiple modification steps with expensive biomolecules. In this study, as a simple and effective alternative to such additional biomolecule treatment, we synthesized amine-functionalized polypyrrole (APPy) that inherently presents cell adhesion-supporting positive charges under physiological conditions. The synthesized APPy provides electrical activity in a moderate range and a hydrophilic surface compared to regular polypyrrole (PPy) homopolymers. Under both serum and serum-free conditions, APPy exhibited superior attachment of human dermal fibroblasts and Schwann cells compared to PPy homopolymer controls. Moreover, Schwann cell adhesion onto the APPy copolymer was at least similar to that on poly-l-lysine treated PPy controls. Our results indicate that amine-functionalized CP substrates will be useful to achieve good cell adhesion and potentially electrically stimulate various cells. In addition, amine functionality present on CPs can further serve as a novel and flexible platform to chemically tether various bioactive molecules, such as growth factors, antibodies, and chemical drugs. PMID:25294089

  18. Conductive paper from lignocellulose wood microfibers coated with a nanocomposite of carbon nanotubes and conductive polymers

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Mangilal; Xing Qi; Lvov, Yuri [Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA 71272 (United States); Shim, Bong Sup; Kotov, Nicholas [Chemical Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States); Varahramyan, Kody [Electrical and Computer Engineering Department, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202 (United States)], E-mail: agarwal@iupui.edu

    2009-05-27

    Composite nanocoating of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) and aqueous dispersion of carbon nanotubes (CNT-PSS) on lignocellulose wood microfibers has been developed to make conductive microfibers and paper sheets. To construct the multilayers on wood microfibers, cationic poly(ethyleneimine) (PEI) has been used in alternate deposition with anionic conductive PEDOT-PSS and solubilized CNT-PSS. Using a Keithley microprobe measurement system, current-voltage measurements have been carried out on single composite microfibers after deposition of each layer to optimize the electrical properties of the coated microfibers. The conductivity of the resultant wood microfibers was in the range of 10{sup -2}-2 S cm{sup -1} depending on the architecture of the coated layer. Further, the conductivity of the coated wood microfibers increased up to 20 S cm{sup -1} by sandwiching multilayers of conductive co-polymer PEDOT-PSS with CNT-PSS through a polycation (PEI) interlayer. Moreover, paper hand sheets were manufactured from these coated wood microfibers with conductivity ranging from 1 to 20 S cm{sup -1}. A paper composite structure consisting of conductive/dielectric/conductive layers that acts as a capacitor has also been fabricated and is reported.

  19. Conductive paper from lignocellulose wood microfibers coated with a nanocomposite of carbon nanotubes and conductive polymers

    Science.gov (United States)

    Agarwal, Mangilal; Xing, Qi; Shim, Bong Sup; Kotov, Nicholas; Varahramyan, Kody; Lvov, Yuri

    2009-05-01

    Composite nanocoating of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) and aqueous dispersion of carbon nanotubes (CNT-PSS) on lignocellulose wood microfibers has been developed to make conductive microfibers and paper sheets. To construct the multilayers on wood microfibers, cationic poly(ethyleneimine) (PEI) has been used in alternate deposition with anionic conductive PEDOT-PSS and solubilized CNT-PSS. Using a Keithley microprobe measurement system, current-voltage measurements have been carried out on single composite microfibers after deposition of each layer to optimize the electrical properties of the coated microfibers. The conductivity of the resultant wood microfibers was in the range of 10-2-2 S cm-1 depending on the architecture of the coated layer. Further, the conductivity of the coated wood microfibers increased up to 20 S cm-1 by sandwiching multilayers of conductive co-polymer PEDOT-PSS with CNT-PSS through a polycation (PEI) interlayer. Moreover, paper hand sheets were manufactured from these coated wood microfibers with conductivity ranging from 1 to 20 S cm-1. A paper composite structure consisting of conductive/dielectric/conductive layers that acts as a capacitor has also been fabricated and is reported.

  20. Conductive paper from lignocellulose wood microfibers coated with a nanocomposite of carbon nanotubes and conductive polymers

    International Nuclear Information System (INIS)

    Composite nanocoating of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) and aqueous dispersion of carbon nanotubes (CNT-PSS) on lignocellulose wood microfibers has been developed to make conductive microfibers and paper sheets. To construct the multilayers on wood microfibers, cationic poly(ethyleneimine) (PEI) has been used in alternate deposition with anionic conductive PEDOT-PSS and solubilized CNT-PSS. Using a Keithley microprobe measurement system, current-voltage measurements have been carried out on single composite microfibers after deposition of each layer to optimize the electrical properties of the coated microfibers. The conductivity of the resultant wood microfibers was in the range of 10-2-2 S cm-1 depending on the architecture of the coated layer. Further, the conductivity of the coated wood microfibers increased up to 20 S cm-1 by sandwiching multilayers of conductive co-polymer PEDOT-PSS with CNT-PSS through a polycation (PEI) interlayer. Moreover, paper hand sheets were manufactured from these coated wood microfibers with conductivity ranging from 1 to 20 S cm-1. A paper composite structure consisting of conductive/dielectric/conductive layers that acts as a capacitor has also been fabricated and is reported.

  1. Applications of conducting polymers and their issues in biomedical engineering

    Science.gov (United States)

    Ravichandran, Rajeswari; Sundarrajan, Subramanian; Venugopal, Jayarama Reddy; Mukherjee, Shayanti; Ramakrishna, Seeram

    2010-01-01

    Conducting polymers (CPs) have attracted much interest as suitable matrices of biomolecules and have been used to enhance the stability, speed and sensitivity of various biomedical devices. Moreover, CPs are inexpensive, easy to synthesize and versatile because their properties can be readily modulated by (i) surface functionalization techniques and (ii) the use of a wide range of molecules that can be entrapped or used as dopants. This paper discusses the various surface modifications of the CP that can be employed in order to impart physico-chemical and biological guidance cues that promote cell adhesion/proliferation at the polymer–tissue interface. This ability of the CP to induce various cellular mechanisms widens its applications in medical fields and bioengineering. PMID:20610422

  2. Electromechanical Behavior of Carbon Nanotubes-Conducting Polymer Films

    Science.gov (United States)

    Kim, Cheol; Liu, Xinyun

    A relationship between strain and applied potential is derived for composite films consisting of single-wall carbon nanotubes (SWNTs) and conductive polymers (CPs). When it is derived, an electrochemical ionic approach is utilized to formulate the electromechanical actuation of the film actuator. This relationship can give us a direct understanding of actuation of the nanoactuator. The results show that the well-aligned SWNTs composite actuator can give good actuation responses and high actuating forces available. The actuation is found to be affected by both SWNTs and CPs components and the actuation of SWNTs component has two kinds of influences on that of the CPs component: reinforcement at the positive voltage and abatement at the negative voltage. Optimizations of SWNTs-CPs composite actuator may be achieved by using well-aligned nanotubes as well as choosing suitable electrolyte and an input voltage range.

  3. Conductive polymer-based microextraction methods: a review.

    Science.gov (United States)

    Bagheri, Habib; Ayazi, Zahra; Naderi, Mehrnoush

    2013-03-12

    Conductive polymers (CPs) are classified as materials which exhibit highly reversible redox behavior and the unusual combined properties of metal and plastics. CPs, due to their multifunctionality, ease of synthesis and their stability, have attracted more attentions in different fields of research, including sample preparation. CPs along with several commercial hydrophilic sorbents, are alternative to the commercially available hydrophobic sorbents which despite their high specific surface areas, have poor interactions and retentions in the extraction of polar compounds. This review covers a general overview regarding the recent progress and new applications of CPs toward their synthesis and use in novel extraction and microextraction techniques including solid phase microextraction (SPME), electrochemically controlled solid-phase microextraction (EC-SPME) and other relevant techniques. Furthermore the contribution of nano-structured CPs in these methodologies is also reviewed. PMID:23452781

  4. Conductive Polymer Porous Film with Tunable Wettability and Adhesion

    Directory of Open Access Journals (Sweden)

    Yuqi Teng

    2015-04-01

    Full Text Available A conductive polymer porous film with tunable wettability and adhesion was fabricated by the chloroform solution of poly(3-hexylthiophene (P3HT and [6,6]-phenyl-C61-butyricacid-methyl-ester (PCBM via the freeze drying method. The porous film could be obtained from the solution of 0.8 wt%, whose pore diameters ranged from 50 nm to 500 nm. The hydrophobic porous surface with a water contact angle (CA of 144.7° could be transferred into a hydrophilic surface with CA of 25° by applying a voltage. The water adhesive force on the porous film increased with the increase of the external voltage. The electro-controllable wettability and adhesion of the porous film have potential application in manipulating liquid collection and transportation.

  5. Intrinsically Conductive Polymer Fibers from Thermoplastic trans-1,4-Polyisoprene.

    Science.gov (United States)

    Han, Peng; Zhang, Xiaohong; Qiao, Jinliang

    2016-05-17

    Herein, we report a new strategy to prepare conductive polymer fibers to overcome the insurmountable weakness of current conductive polymer fibers. First, special thermoplastic polymers are processed into polymer fibers using a conventional melt-spinning process, and then the nonconductive polymer fibers are converted into intrinsically conductive polymer fibers. Using this new strategy, intrinsically conductive polymer fibers have been prepared by melt spinning low-cost thermoplastic trans-1,4-polyisoprene and doping with iodine, which can be as fine as 0.01 mm, and the resistivity can be as low as 10(-2) Ω m. Moreover, it has been found that drawing can improve the orientation of trans-1,4-polyisoprene crystals in the fibers and, thus, the conductivity of the conductive polymer fibers. Therefore, conductive fibers with excellent conductivities can be prepared by large drawing ratios before doping. Such conductive polymer fibers with low cost could be used in textile, clothing, packing, and other fields, which would benefit both industry and daily life. The newly developed method also allows one to produce conductive polymers of any shape besides fibers for antistatic or conductive applications. PMID:27135825

  6. Two-Dimensional Electronic Excitations in Self-Assembled Conjugated Polymer Nanocrystals

    Science.gov (United States)

    Österbacka, R.; An, C. P.; Jiang, X. M.; Vardeny, Z. V.

    2000-02-01

    Several spectroscopic methods were applied to study the characteristic properties of the electronic excitations in thin films of regioregular and regiorandom polythiophene polymers. In the regioregular polymers, which form two-dimensional lamellar structures, increased interchain coupling strongly influences the traditional one-dimensional electronic properties of the polymer chains. The photogenerated charge excitations (polarons) show two-dimensional delocalization that results in a relatively small polaronic energy, multiple absorption bands in the gap where the lowest energy band becomes dominant, and associated infrared active vibrations with reverse absorption bands caused by electron-vibration interferences. The relatively weak absorption bands of the delocalized polaron in the visible and near-infrared spectral ranges may help to achieve laser action in nanocrystalline polymer devices using current injection.

  7. PATTERN RECOGNITION STUDIES OF HALOGENATED ORGANIC COMPOUNDS USING CONDUCTING POLYMER SENSOR ARRAYS. (R825323)

    Science.gov (United States)

    Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...

  8. Quantum soliton conductivity in polymers: a field theory approach

    International Nuclear Information System (INIS)

    Full text: The discovery of a tremendous increase in the electrical conductivity of polyacetylene, the simplest linear conjugated polymer, when doped with either halogens or alkalis, was a breakthrough of far reaching consequences in physics and chemistry. The fact that the trans-isomer occurs in two degenerate species opens the possibility of occurrence of soliton defects interconnecting them. Indeed, quantum solitons or polarons are supposed to play a crucial role in the electric conductivity of polyacetylene, in the intermediate doping regime. In this work, we present an exact fully quantized calculation of the quantum soliton conductivity in polyacetylene and show that it vanishes exactly. This strongly suggests that dynamic solitons are not the charge carriers in polyacetylene. Rather, polarons, which are basically soliton-anti soliton bound states should be responsible for the transport of charge in the intermediate doping regime of polyacetylene. This result is obtained by applying a general method of soliton quantization, based on order-disorder duality, to a Z(2)-symmetric complex extension of the TLM (Takayama, Lin-Liu and Maki) dimerization effective field theory. We show that, in this theory, polyacetylene solitons are sine-Gordon solitons in the phase of the complex field. (author)

  9. Polymer-Enhanced Stability of Inorganic Perovskite Nanocrystals and Their Application in Color Conversion LEDs.

    Science.gov (United States)

    Meyns, Michaela; Perálvarez, Mariano; Heuer-Jungemann, Amelie; Hertog, Wim; Ibáñez, Maria; Nafria, Raquel; Genç, Aziz; Arbiol, Jordi; Kovalenko, Maksym V; Carreras, Josep; Cabot, Andreu; Kanaras, Antonios G

    2016-08-01

    Cesium lead halide (CsPbX3, X = Cl, Br, I) nanocrystals (NCs) offer exceptional optical properties for several potential applications but their implementation is hindered by a low chemical and structural stability and limited processability. In the present work, we developed a new method to efficiently coat CsPbX3 NCs, which resulted in their increased chemical and optical stability as well as processability. The method is based on the incorporation of poly(maleic anhydride-alt-1-octadecene) (PMA) into the synthesis of the perovskite NCs. The presence of PMA in the ligand shell stabilizes the NCs by tightening the ligand binding, limiting in this way the NC surface interaction with the surrounding media. We further show that these NCs can be embedded in self-standing silicone/glass plates as down-conversion filters for the fabrication of monochromatic green and white light emitting diodes (LEDs) with narrow bandwidths and appealing color characteristics. PMID:27454750

  10. Understanding hopping transport and thermoelectric properties of conducting polymers

    Science.gov (United States)

    Ihnatsenka, S.; Crispin, X.; Zozoulenko, I. V.

    2015-07-01

    We calculate the conductivity σ and the Seebeck coefficient S for the phonon-assisted hopping transport in conducting polymers poly(3,4-ethylenedioxythiophene) or PEDOT, experimentally studied by Bubnova et al. [J. Am. Chem. Soc. 134, 16456 (2012)], 10.1021/ja305188r. We use the Monte Carlo technique as well as the semianalytical approach based on the transport energy concept. We demonstrate that both approaches show a good qualitative agreement for the concentration dependence of σ and S . At the same time, we find that the semianalytical approach is not in a position to describe the temperature dependence of the conductivity. We find that both Gaussian and exponential density of states (DOS) reproduce rather well the experimental data for the concentration dependence of σ and S giving similar fitting parameters of the theory. The obtained parameters correspond to a hopping model of localized quasiparticles extending over 2-3 monomer units with typical jumps over a distance of 3-4 units. The energetic disorder (broadening of the DOS) is estimated to be 0.1 eV. Using the Monte Carlo calculation we reproduce the activation behavior of the conductivity with the calculated activation energy close to the experimentally observed one. We find that for a low carrier concentration a number of free carriers contributing to the transport deviates strongly from the measured oxidation level. Possible reasons for this behavior are discussed. We also study the effect of the dimensionality on the charge transport by calculating the Seebeck coefficient and the conductivity for the cases of three-, two-, and one-dimensional motion.

  11. Polymerization of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) around living neural cells

    OpenAIRE

    Richardson-Burns, Sarah M.; Hendricks, Jeffrey L.; Foster, Brian; Povlich, Laura K.; Kim, Dong-Hwan; Martin, David C.

    2006-01-01

    In this paper we describe interactions between neural cells and the conducting polymer poly(3,4-ethylenedioxythiophene (PEDOT) toward development of electrically conductive biomaterials intended for direct, functional contact with electrically-active tissues such as the nervous system, heart, and skeletal muscle. We introduce a process for polymerizing PEDOT around living cells and describe a neural cell-templated conducting polymer coating for microelectrodes and a hybrid conducting polymer-...

  12. Thermal Conductivity of Carbon Nanotubes and their Polymer Nanocomposites: A Review

    OpenAIRE

    Han, Zhidong; Fina, Alberto

    2011-01-01

    Thermally conductive polymer composites offer new possibilities for replacing metal parts in several applications, including power electronics, electric motors and generators, heat exchangers, etc., thanks to the polymer advantages such as light weight, corrosion resistance and ease of processing. Current interest to improve the thermal conductivity of polymers is focused on the selective addition of nanofillers with high thermal conductivity. Unusually high thermal conductivity makes carbon ...

  13. Designer coordination polymers: dimensional crossover architectures and proton conduction.

    Science.gov (United States)

    Yamada, Teppei; Otsubo, Kazuya; Makiura, Rie; Kitagawa, Hiroshi

    2013-08-21

    Coordination polymers (CPs) have large degrees of freedom in framework compositions and in the structures and environment of the inner pores. This review focuses on the recent significant progress achieved by controlling these degrees of freedom. Two breakthroughs are reviewed for constructing sophisticated structures of CP frameworks, especially in dimensional crossover regions. The first is the synthesis of quasi one-dimensional halogen-bridged coordinative tubes by applying state-of-the-art techniques of coordination chemistry. The electronic state of the coordinative tube was studied by structural, spectroscopic and theoretical methods and found to be distinct from conventional one-dimensional systems. The second breakthrough is the achievement of a quasi-two-dimensional architecture by combining Langmuir-Blodgett and layer-by-layer methods. Two-dimensional LB CP films were prepared on liquid; the films were stacked layer by layer, and a crystalline quasi-two-dimensional structure was constructed. This review also covers the design of the environment of the inner pore, where hydrogen bond networks with various acidic sites were modified. By appropriate design of the hydrogen bond network, proton-conductive CPs are invented, which are summarized in this review. Types of proton donor sites are discussed and classified, and superprotonic conductive CPs were achieved in these investigations. These results will provide new strategies for constructing functional materials for smart devices.

  14. A New Conducting Polymer Electrode for Organic Electroluminescence Devices

    Institute of Scientific and Technical Information of China (English)

    QU Shu; PENG Jing-Cui

    2008-01-01

    @@ Conducting polymer polydimethylsiloxane (PDMS) is studied for the high performance electrode of organic electroluminescence devices. A method to prepare the electrode consisting of a SiC thin film and PDMS is investigated. By using ultra thin SiC films with different thicknesses, the organic electroluminescenee devices are obtained in an ultra vacuum system with the model device PDMS/SiC/PPV/Alq3, where PPV is poly para-phenylene vinylene and Alq3 is tris(8-hydroxyquinoline) aluminium. The capacitance-voltage (C-V), capacitance-frequency (C-F), current-voltage (I- V), radiation intensity-voltage (R- V) and luminance efficiency-voltage (E-V) measurements are systematically studied to investigate the conductivity, Fermi align-ment and devices properties in organic semiconductors. Scanning Kelvin probe measurement shows that the work function of PDMS/SiC anode with a 2.5-nm SiC over layer can be increased by as much as 0.28eV, compared to the conventional ITO anode. The result is attributed to the charge transfer effect and ohmic contacts at the interface.

  15. Soft capacitor fibers using conductive polymers for electronic textiles

    CERN Document Server

    Gu, Jian Feng; Skorobogatiy, Maksim

    2010-01-01

    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its crossection the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometres of fibers can be obtained from a single preform with fiber diameters ranging between 500um -1000um. A typical measured capacitance of our fibers is 60-100 nF/m and it is independent of the fiber diameter. For comparison, a coaxial cable of the comparable dimensions would have only ~0.06nF/m capacitance. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kOhm/L, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials...

  16. Soft capacitor fibers using conductive polymers for electronic textiles

    Science.gov (United States)

    Gu, Jian Feng; Gorgutsa, Stephan; Skorobogatiy, Maksim

    2010-11-01

    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its cross section the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using the fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometers of fibers can be obtained from a single preform with fiber diameters ranging between 500 and 1000 µm. A typical measured capacitance of our fibers is 60-100 nF m-1 and it is independent of the fiber diameter. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kΩ m L-1, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, the absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage.

  17. Synthesis of Conductive Nanofillers/Nanofibers and Electrical Properties of their Conductive Polymer Composites

    Science.gov (United States)

    Sarvi, Ali

    Thanks to their corrosion resistance, light weight, low cost, and ease of processing, electrically conducting polymer composites (CPCs) have received significant attention for the replacement of metals and inorganic materials for sensors, actuators, supercapacitors, and electromagnetic interference (EMI) shields. In this PhD thesis, high aspect ratio conductive nanofillers namely copper nanowires (CuNWs) and multiwall carbon nanotubes (MWCNTs) were coated with polyaniline (PANi) using solution mixing and in-situ polymerization method, respectively. Transmission electron microscopy (TEM) showed a smooth polyaniline nano-coating between 5--18 nm in thickness on the nanofillers' surface. The coating thickness and; consequently, electrical conductivity was controlled and tuned by polyaniline/aniline concentration in solution. Composites with tunable conductivity may be used as chemisensors, electronic pressure sensors and switches. Coated nanofillers demonstrated better dispersion in polystyrene (PS) and provided lower electrical percolation threshold. Dispersion of nanofillers in PS was investigated using rheological measurements and confirmed with electron micrographs and nano-scale images of CPCs. Polyaniline (PANi), when used as a coating layer, was able to attenuate electromagnetic (EM) waves via absorption and store electrical charges though pseudocapacitance mechanism. The dielectric measurements of MWCNT-PANi/PS composites showed one order of magnitude increase in real electrical permittivity compared to that of MWCNT/PS composites making them suitable for charge storage purposes. Incorporation of PANi also brought a new insight into conductive network formation mechanism in electrospun mats where the orientation of conductive high aspect ratio nanofillers is a major problem. Conductive nanofibers of poly(vinylidene fluoride) (PVDF) filled with coated multiwall carbon nanotubes (MWCNTs) were fabricated using electrospinning. These highly oriented PVDF

  18. Porous palladium coated conducting polymer nanoparticles for ultrasensitive hydrogen sensors

    Science.gov (United States)

    Lee, Jun Seop; Kim, Sung Gun; Cho, Sunghun; Jang, Jyongsik

    2015-12-01

    Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm) and stability toward hydrogen gas at room temperature due to the palladium sensing layer.Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm

  19. A facile synthesis and photoluminescence properties of water-dispersible Re3+ doped CeF3 nanocrystals and solid nanocomposites with polymers.

    Science.gov (United States)

    Li, Chunguang; Li, Feifei; Li, Tao; Bai, Tianyu; Wang, Long; Shi, Zhan; Feng, Shouhua

    2012-04-28

    Water-dispersible Re(3+) doped CeF(3) colloidal nanocrystals with well controllable morphology and high crystallinity have been successfully synthesized through a solvothermal process. The TEM images illustrate that the Re(3+) doped CeF(3) nanocrystals are rectangular (or cubic) with a mean diameter of ~10 nm. The excellent dispersibility in some of the polar solvents including water is achieved by using polyethyleneimine as the capping agent. The amine groups of the polymer chains on one hand bind to the nanocrystal surface; on the other hand the free ones could link to functional materials including bio-molecules. The CeF(3) nanocrystals doped with Tb(3+) and Dy(3+) ions show the characteristic emission of Tb(3+ 5)D(4)-(7)F(J) (J = 6-3, with (5)D(4)-(7)F(5) green emission at 542 nm as the strongest one) and Dy(3+ 4)F(9/2)-(6)H(15/2) (blue-green color at 478 nm) and (4)F(9/2)-(6)H(13/2) (yellow color at 571 nm) transitions, respectively. The energy transfer from Ce(3+) to Tb(3+) and Dy(3+) was also investigated in detail. In vitro studies of Re(3+) doped CeF(3) colloidal nanocrystals on HepG2 cells confirm their excellent biological compatibility. The obtained solid CeF(3) : Tb(3+)/PDMS nanocomposites are very stable and flexible and exhibit strong green photoluminescence upon UV excitation. PMID:22398580

  20. A Route for Polymer Nanocomposites with Engineered Electrical Conductivity and Percolation Threshold

    OpenAIRE

    Drzal, Lawrence T.; Hiroyuki Fukushima; Kyriaki Kalaitzidou

    2010-01-01

    Polymer nanocomposites with engineered electrical properties can be made by tuning the fabrication method, processing conditions and filler’s geometric and physical properties. This work focuses on investigating the effect of filler’s geometry (aspect ratio and shape), intrinsic electrical conductivity, alignment and dispersion within the polymer, and polymer crystallinity, on the percolation threshold and electrical conductivity of polypropylene based nanocomposites. The conductive reinforce...

  1. Cotton Fabric Coated with Conducting Polymers and its Application in Monitoring of Carnivorous Plant Response

    OpenAIRE

    Václav Bajgar; Marek Penhaker; Lenka Martinková; Andrej Pavlovič; Patrycja Bober; Miroslava Trchová; Jaroslav Stejskal

    2016-01-01

    The paper describes the electrical plant response to mechanical stimulation monitored with the help of conducting polymers deposited on cotton fabric. Cotton fabric was coated with conducting polymers, polyaniline or polypyrrole, in situ during the oxidation of respective monomers in aqueous medium. Thus, modified fabrics were again coated with polypyrrole or polyaniline, respectively, in order to investigate any synergetic effect between both polymers with respect to conductivity and its sta...

  2. The contact resistance force relationship of an intrinsically conducting polymer interface

    OpenAIRE

    Lam, Yu-Zhi (Liza); Swingler, J.; McBride, J. W.

    2006-01-01

    Investigations on contact connector materials for different applications such as in the automotive industry have focused toward the increasing interest of using conducting polymers, as compared to conventional metallic contacts. The aim is to achieve overall improvements in performance as well as cost effectiveness. Currently, extrinsic conducting polymers (ECPs) are employed as conductive coats or adhesives at contact interfaces. However, frictional abrasion within the metal doped polymer (E...

  3. Efficiency of a Compact Elliptical Planar Ultra-Wideband Antenna Based on Conductive Polymers

    OpenAIRE

    Christophe Fumeaux; Roderick Shepherd; Bo Weng; Akhilesh Verma; Van-Tan Truong; Thomas Kaufmann

    2012-01-01

    A planar antenna for ultra-wideband (UWB) applications covering the 3.1–10.6 GHz range has been designed as a test bed for efficiency measurements of antennas manufactured using polymer conductors. Two types of conductive polymers, PEDOT and PPy (polypyrrole), with very different thicknesses and conductivities have been selected as conductors for the radiating elements. A comparison between measured radiation patterns of the conductive polymers and a copper reference antenna allows to estimat...

  4. Rate dependence of electrical and mechanical properties of conductive polymer nanocomposites

    OpenAIRE

    Foley J.R.; Stilson C.L.; Smith K.K.G.; McKinion C.M.; Chen C.; Ganguli S; Roy A.K

    2015-01-01

    Conductive polymer nanocomposites with enhanced electrical and thermal properties show promise as an alternative solution for electronic materials. For example, electronic interconnect materials will have comparable electrical and thermal conductivity to solder with an increased operating range of strain and temperature. This paper documents the fabrication and experimental evaluation of a prototype conductive polymer nanocomposite. Material selection, fabrication processes, and initial chara...

  5. Rational design and synthesis of semi-conducting polymers.

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Bryan Matthew; Reeder, Craig; Cordaro, Joseph Gabriel

    2010-12-01

    A rational approach was used to design polymeric materials for thin-film electronics applications, whereby theoretical modeling was used to determine synthetic targets. Time-dependent density functional theory calculations were used as a tool to predict the electrical properties of conjugated polymer systems. From these results, polymers with desirable energy levels and band-gaps were designed and synthesized. Measurements of optoelectronic properties were performed on the synthesized polymers and the results were compared to those of the theoretical model. From this work, the efficacy of the model was evaluated and new target polymers were identified.

  6. Carbon Nanotube-Conducting Polymer Composites Based Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Prakash; R.Somani; M.Umeno

    2007-01-01

    1 Results Combination of carbon nanotubes (CN) with polymers is important for application towards value added composites,solar cells,fuel cells etc.Especially interesting is the combination of CN with π-conjugated polymers because of the potential interaction between the highly delocalized π-electrons of the CN and the π-electrons correlated with the lattice of polymer skeleton.Efficient exciton dissociation due to electron transfer from the photoexcited polymer to CN is of interest for photovoltaic app...

  7. Electroanalytical measurements without electrolytes: conducting polymers as probes for redox titration in non-conductive organic media.

    Science.gov (United States)

    Lange, Ulrich; Mirsky, Vladimir M

    2012-09-26

    Electroanalytical methods have been applied only in conducting media. An application of conducting polymers allows to overcome this limitation. If such material is in electrochemical equilibrium with dissolved redox active species, its electrical conductivity depends on the redox potential of these species. Therefore, conductometric measurements with conducting polymers can provide about the same information as classical redox electrodes. The approach was applied for redox titration. Equivalent points obtained by this titration in aqueous and organic electrolytes were identical. Then the approach was applied for determination of bromine number by redox titration in non-conducting organic phase.

  8. Electrochemical DNA Hybridization Sensors Based on Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Md. Mahbubur Rahman

    2015-02-01

    Full Text Available Conducting polymers (CPs are a group of polymeric materials that have attracted considerable attention because of their unique electronic, chemical, and biochemical properties. This is reflected in their use in a wide range of potential applications, including light-emitting diodes, anti-static coating, electrochromic materials, solar cells, chemical sensors, biosensors, and drug-release systems. Electrochemical DNA sensors based on CPs can be used in numerous areas related to human health. This review summarizes the recent progress made in the development and use of CP-based electrochemical DNA hybridization sensors. We discuss the distinct properties of CPs with respect to their use in the immobilization of probe DNA on electrode surfaces, and we describe the immobilization techniques used for developing DNA hybridization sensors together with the various transduction methods employed. In the concluding part of this review, we present some of the challenges faced in the use of CP-based DNA hybridization sensors, as well as a future perspective.

  9. Functionalised inherently conducting polymers as low biofouling materials.

    Science.gov (United States)

    Zhang, Binbin; Nagle, Alex R; Wallace, Gordon G; Hanks, Timothy W; Molino, Paul J

    2015-01-01

    Diatoms are a major component of microbial biofouling layers that develop on man-made surfaces placed in aquatic environments, resulting in significant economic and environmental impacts. This paper describes surface functionalisation of the inherently conducting polymers (ICPs) polypyrrole (PPy) and polyaniline (PANI) with poly(ethylene glycol) (PEG) and their efficacy as fouling resistant materials. Their ability to resist interactions with the model protein bovine serum albumin (BSA) was tested using a quartz crystal microbalance with dissipation monitoring (QCM-D). The capacity of the ICP-PEG materials to prevent settlement and colonisation of the fouling diatom Amphora coffeaeformis (Cleve) was also assayed. Variations were demonstrated in the dopants used during ICP polymerisation, along with the PEG molecular weight, and the ICP-PEG reaction conditions, all playing a role in guiding the eventual fouling resistant properties of the materials. Optimised ICP-PEG materials resulted in a significant reduction in BSA adsorption, and > 98% reduction in diatom adhesion.

  10. Using artificial intelligence methods to design new conducting polymers

    Directory of Open Access Journals (Sweden)

    Ronaldo Giro

    2003-12-01

    Full Text Available In the last years the possibility of creating new conducting polymers exploring the concept of copolymerization (different structural monomeric units has attracted much attention from experimental and theoretical points of view. Due to the rich carbon reactivity an almost infinite number of new structures is possible and the procedure of trial and error has been the rule. In this work we have used a methodology able of generating new structures with pre-specified properties. It combines the use of negative factor counting (NFC technique with artificial intelligence methods (genetic algorithms - GAs. We present the results for a case study for poly(phenylenesulfide phenyleneamine (PPSA, a copolymer formed by combination of homopolymers: polyaniline (PANI and polyphenylenesulfide (PPS. The methodology was successfully applied to the problem of obtaining binary up to quinternary disordered polymeric alloys with a pre-specific gap value or exhibiting metallic properties. It is completely general and can be in principle adapted to the design of new classes of materials with pre-specified properties.

  11. Conductivity study and fourier transform infrared (FTIR) characterization of methyl cellulose solid polymer electrolyte with sodium iodide conducting ion

    International Nuclear Information System (INIS)

    Sodium ion (Na+) based solid polymer electrolyte (SPE) has been prepared using solution cast technique with distilled water as solvent and Methylcellulose (MC) as a polymer host. Methylcellulose polymer was chosen as the polymer host due to the abundance of lone pair electrons in the carbonyl and C-O-C constituents, which in turn provide multiple hopping sites for the Na+ conducting ions. Variable compositions of sodium iodide (NaI) salt were prepared to investigate the optimum MC-NaI weight ratio. Results from Electrical Impedance Spectroscopy (EIS) technique show that pure methylcellulose has a low conductivity of 3.61 × 10−11 S/cm.The conductivity increases as NaI content increases up to optimum NaIcomposition of 40 wt%, which yields an average conductivity of 2.70 × 10−5 S/cm

  12. Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

    Science.gov (United States)

    Jarad, Amer N.; Ibrahim, Kamarulazizi; Ahmed, Nasser M.

    2016-07-01

    In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10-5 (Ω.cm)-1, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

  13. Review on Optical and Electrical Properties of Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Manisha Bajpai

    2016-01-01

    Full Text Available We reviewed optical and electrical properties of conjugated polymers. The charge transport models to describe the hole and electron transport mechanism are also included in the electrical properties of conjugated polymers. The effect of optical and electrical properties after doping is also indexed in this paper.

  14. New Secondary Batteries Using Electronically Conductive Polymer Cathodes

    Science.gov (United States)

    Martin, Charles R.; White, Ralph E.

    1991-01-01

    A Li/Polypyrrole secondary battery was designed and built, and the effect of controlling the morphology of the polymer on enhancement of counterion diffusion in the polymer phase was explored. The experimental work was done at Colorado State University, while the mathematical modeling of the battery was done at Texas A and M University. Manuscripts and publications resulting from the project are listed.

  15. Electron conductive three-dimensional polymer of cuboidal C60

    OpenAIRE

    Yamanaka, Shoji; Kubo, Akira; Inumaru, Kei; Komaguchi, Kenji; Kini, N. S.; Inoue, Toru; Irifune, Tetsuo

    2006-01-01

    Single crystals of three-dimensional (3D) C60 polymer were prepared by the topotactic conversion of two-dimensional (2D) C60 polymer single crystals at a pressure of 15 GPa at 600°C. The x-ray single crystal study revealed that the 3D C60 polymer crystallized in a body centered orthorhombic space group Immm, and spherical C60 monomer units were substantially deformed to rectangular parallelepiped (cuboidal) shapes, each unit being bonded to eight cuboidal C60 neighbors via [3+3] cycloaddition...

  16. Design of electrically conducting polymer hybrid composites based on polyvinyl chloride and polyethylene

    OpenAIRE

    Kuryptya, Yaroslav; Sova, Nadiya; Savchenko, Bohdan; Slieptsov, Aleksander; Plavan, Viktoriia

    2016-01-01

    Interest to electrically conducting polymer composite materials in recent times has grown considerably, which is associated with the design of new branches of science and technology. The existing analogues are different in the complexity of production and high cost. One of the ways of solving the problem may be designing polymer composite materials with a combined filler. The research was carried out on creating electrically conducting hybrid polymer composites, based on emulsion polyvinyl ch...

  17. Performance of conducting polymer electrodes for stimulating neuroprosthetics

    Science.gov (United States)

    Green, R. A.; Matteucci, P. B.; Hassarati, R. T.; Giraud, B.; Dodds, C. W. D.; Chen, S.; Byrnes-Preston, P. J.; Suaning, G. J.; Poole-Warren, L. A.; Lovell, N. H.

    2013-02-01

    Objective. Recent interest in the use of conducting polymers (CPs) for neural stimulation electrodes has been growing; however, concerns remain regarding the stability of coatings under stimulation conditions. These studies examine the factors of the CP and implant environment that affect coating stability. The CP poly(ethylene dioxythiophene) (PEDOT) is examined in comparison to platinum (Pt), to demonstrate the potential performance of these coatings in neuroprosthetic applications. Approach. PEDOT is coated on Pt microelectrode arrays and assessed in vitro for charge injection limit and long-term stability under stimulation in biologically relevant electrolytes. Physical and electrical stability of coatings following ethylene oxide (ETO) sterilization is established and efficacy of PEDOT as a visual prosthesis bioelectrode is assessed in the feline model. Main results. It was demonstrated that PEDOT reduced the potential excursion at a Pt electrode interface by 72% in biologically relevant solutions. The charge injection limit of PEDOT for material stability was found to be on average 30× larger than Pt when tested in physiological saline and 20× larger than Pt when tested in protein supplemented media. Additionally stability of the coating was confirmed electrically and morphologically following ETO processing. It was demonstrated that PEDOT-coated electrodes had lower potential excursions in vivo and electrically evoked potentials (EEPs) could be detected within the visual cortex. Significance. These studies demonstrate that PEDOT can be produced as a stable electrode coating which can be sterilized and perform effectively and safely in neuroprosthetic applications. Furthermore these findings address the necessity for characterizing in vitro properties of electrodes in biologically relevant milieu which mimic the in vivo environment more closely.

  18. Semiconductor Nanomaterials and Nanocrystals

    Directory of Open Access Journals (Sweden)

    N.V. Stetsyk

    2015-06-01

    Full Text Available This article introduces an innovative synthesis of doped nanocrystals and aims at expanding the fundamental understanding of charge transport in these doped nanocrystal films. The list of semiconductor nanocrystals that can be doped is large, and if one combines that with available dopants, an even larger set of materials with interesting properties and applications can be generated. In addition to doping, another promising route to increase conductivity in nanocrystal films is to use nanocrystals with high ionic conductivities. This work also examines this possibility by studying new phases of mixed ionic and electronic conductors at the nanoscale. Such a versatile approach may open new pathways for interesting fundamental research, and also lay the foundation for the creation of novel materials with important application.

  19. A general approach toward enhancement of pseudocapacitive performance of conducting polymers by redox-active electrolytes

    KAUST Repository

    Chen, Wei

    2014-12-01

    A general approach is demonstrated where the pseudocapacitive performance of different conducting polymers is enhanced in redox-active electrolytes. The concept is demonstrated using several electroactive conducting polymers, including polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene). As compared to conventional electrolytes, the redox-active electrolytes, prepared by simply adding a redox mediator to the conventional electrolyte, can significantly improve the energy storage capacity of pseudocapacitors with different conducting polymers. The results show that the specific capacitance of conducting polymer based pseudocapacitors can be increased by a factor of two by utilization of the redox-active electrolytes. In fact, this approach gives some of the highest reported specific capacitance values for electroactive conducting polymers. Moreover, our findings present a general and effective approach for the enhancement of energy storage performance of pseudocapacitors using a variety of polymeric electrode materials. © 2014 Elsevier B.V. All rights reserved.

  20. Protocol and cell responses in three-dimensional conductive collagen gel scaffolds with conductive polymer nanofibres for tissue regeneration

    OpenAIRE

    Sirivisoot, Sirinrath; Pareta, Rajesh; Harrison, Benjamin S.

    2014-01-01

    It has been established that nerves and skeletal muscles respond and communicate via electrical signals. In regenerative medicine, there is current emphasis on using conductive nanomaterials to enhance electrical conduction through tissue-engineered scaffolds to increase cell differentiation and tissue regeneration. We investigated the role of chemically synthesized polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT) conductive polymer nanofibres for conductive gels. To mimic a na...

  1. Investigating the Inter-Tube Conduction Mechanism in Polycarbonate Nanocomposites Prepared with Conductive Polymer-Coated Carbon Nanotubes

    OpenAIRE

    Ventura, Isaac Aguilar; Zhou, Jian; Lubineau, Gilles

    2015-01-01

    A well-known strategy to improve the electrical conductivity of polymers is to dope them with high-aspect-ratio and conductive nanoparticles such as carbon nanotubes (CNTs). However, these nanocomposites also exhibit undesirable properties such as damage-sensitive and history-dependent conductivity because their macroscopic electrical conductivity is largely determined by the tunneling effect at the tube/tube interface. To reduce these issues, new nanocomposites have been developed with CNTs ...

  2. Application of nano-structured conducting polymers to humidity sensing

    Science.gov (United States)

    Park, Pilyeon

    Nanostructures, such as nanowires, nanocolumns, and nanotubes, have attracted a lot of attention because of their huge potential impact on a variety of applications. For sensor applications, nanostructures provide high surface area to volume ratios. The high surface area to volume ratio allows more reaction areas between target species and detection materials and also improves the detection sensitivity and response time. The main goal of this research was to exploit the advantages and develop innovative methods to accomplish the synthesis of nanowires and nano-coulmn conducting polymers used in humidity detection. To accomplish this, two fabrication methods are used. The first one utilizes the geometric confinement effect of a temporary nanochannel template to orient, precisely position, and assemble Polyaniline (PANI) nanowires as they are synthesized. The other approach is to simply spin-coat a polymer onto a substrate, and then oxygen plasma etch to generate a nano-columned Polyethylenedioxythiophene (PEDOT) thin film. 200 nm silicon oxide coated wafers with embedded platinum electrodes are used as a substrate for both fabrication methods. The biggest advantage of this first method is that it is simple, requires a single-step, i.e., synthesizing and positioning procedures are carried out simultaneously. The second method is potentially manufacturable and economic yet environmentally safe. These two methods do not produce extra nano-building materials to discard or create a health hazard. Both PANI nanowires and nano-columned PEDOT films have been tested for humidity detection using a system designed and built for this research to monitor response (current changes) to moisture, To explain the surface to volume ratio effect, 200 nm PANI nanowires and 10 microm PANI wires were directly compared for detecting moisture, and it was shown that the PANI nanowire had a better sensitivity. It was found difficult to monitor the behaviors of the PEDOT reaction to varying

  3. Micropatterning of a stretchable conductive polymer using inkjet printing and agarose stamping

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Hassager, Ole; Larsen, Niels Bent;

    2007-01-01

    A highly conducting stretchable polymer material has been patterned using additive inkjet printing and by subtractive agarose stamping of a deactivation agent (hypochlorite). The material consisted of elastomeric polyurethane combined in an interpenetrating network with a conductive polymer, poly(3......,4-ethylenedioxythiophene) (PEDOT). The agarose stamping produced 50 μm wide conducting lines with high spatial fidelity. The deactivation agent was found to cause some degradation of the remaining conducting lines, as revealed by a stronger increase in resistance upon straining compared to the pristine polymer material...

  4. Characterization of proton conducting blend polymer electrolyte using PVA-PAN doped with NH4SCN

    Science.gov (United States)

    Premalatha, M.; Mathavan, T.; Selvasekarapandian, S.; Genova, F. Kingslin Mary; Umamaheswari, R.

    2016-05-01

    Polymer electrolytes with proton conductivity based on blend polymer using polyvinyl alcohol (PVA) and poly acrylo nitrile (PAN) doped with ammonium thiocyanate have been prepared by solution casting method using DMF as solvent. The complex formation between the blend polymer and the salt has been confirmed by FTIR Spectroscopy. The amorphous nature of the blend polymer electrolytes have been confirmed by XRD analysis. The highest conductivity at 303 K has been found to be 3.25 × 10-3 S cm-1 for 20 mol % NH4SCN doped 92.5PVA:7.5PAN system. The increase in conductivity of the doped blend polymer electrolytes with increasing temperature suggests the Arrhenius type thermally activated process. The activation energy is found to be low (0.066 eV) for the highest conductivity sample.

  5. Effect of complexing salt on conductivity of PVC/PEO polymer blend electrolytes

    Indian Academy of Sciences (India)

    S Rajendran; Ravi Shanker Babu; M Usha Rani

    2011-12-01

    Solid polymer electrolyte membrane comprising poly(vinyl chloride) (PVC), poly(ehylene oxide) (PEO) and different lithium salts (LiClO4, LiBF4 and LiCF3SO3) were prepared by the solution casting technique. The effect of complexing salt on the ionic conductivity of the PVC/PEO host polymer is discussed. Solid polymer electrolyte films were characterized by X-ray diffraction, FTIR spectroscopy, TG/DTA and ac impedance spectroscopic studies. The conductivity studies of these solid polymer electrolyte (SPE) films are carried out as a function of frequency at various temperatures ranging from 302 K to 353 K. The maximum room temperature ionic conductivity is found to be 0.079 × 10-4 S cm-1 for the film containing LiBF4 as the complexing salt. The temperature dependence of the conductivity of polymer electrolyte films seems to obey the Vogel–Tamman–Fulcher (VTF) relation.

  6. Polymer Vesicles as Robust Scaffolds for the Directed Assembly of Highly Crystalline Nanocrystals

    KAUST Repository

    Wang, Mingfeng

    2009-12-15

    We report the incorporation of various inorganic nanoparticles (NPs) (PbS, LaOF, LaF3, and TiO2, each capped by oleic acid, and CdSe/ZnS core/shell QDs capped by trioctylphosphine oxide) into vesicles (d = 70-150 nm) formed by a sample of poly(styrene-b-acrylic acid) (PS4o4-b-PAA 62, where the subscripts refer to the degree of polymerization) in mixtures of tetrahydrofuran (THF), dioxane, and water. The block copolymer formed mixtures of crew-cut micelles and vesicles with some enhancement of the vesicle population when the NPs were present. The vesicle fraction could be isolated by selective sedimentation via centrifugation, followed by redispersion in water. The NPs appeared to be incorporated into the PAA layers on the internal and external walls of the vesicles (strongly favoring the former). NPs on the exterior surface of the vesicles could be removed completely by treating the samples with a solution of ethylenediaminetetraacetate (EDTA) in water. The triangular nanoplatelets of LaF3 behaved differently. Stacks of these platelets were incorporated into solid colloidal entities, similar in size to the empty vesicles that accompanied them, during the coassembly as water was added to the polymer/LaF3/THF/ dioxane mixture. © 2009 American Chemical Society.

  7. Mechanisms of Local Stress Sensing in Multifunctional Polymer Films Using Fluorescent Tetrapod Nanocrystals.

    Science.gov (United States)

    Raja, Shilpa N; Zherebetskyy, Danylo; Wu, Siva; Ercius, Peter; Powers, Alexander; Olson, Andrew C K; Du, Daniel X; Lin, Liwei; Govindjee, Sanjay; Wang, Lin-Wang; Xu, Ting; Alivisatos, A Paul; Ritchie, Robert O

    2016-08-10

    Nanoscale stress-sensing can be used across fields ranging from detection of incipient cracks in structural mechanics to monitoring forces in biological tissues. We demonstrate how tetrapod quantum dots (tQDs) embedded in block copolymers act as sensors of tensile/compressive stress. Remarkably, tQDs can detect their own composite dispersion and mechanical properties with a switch in optomechanical response when tQDs are in direct contact. Using experimental characterizations, atomistic simulations and finite-element analyses, we show that under tensile stress, densely packed tQDs exhibit a photoluminescence peak shifted to higher energies ("blue-shift") due to volumetric compressive stress in their core; loosely packed tQDs exhibit a peak shifted to lower energies ("red-shift") from tensile stress in the core. The stress shifts result from the tQD's unique branched morphology in which the CdS arms act as antennas that amplify the stress in the CdSe core. Our nanocomposites exhibit excellent cyclability and scalability with no degraded properties of the host polymer. Colloidal tQDs allow sensing in many materials to potentially enable autoresponsive, smart structural nanocomposites that self-predict impending fracture. PMID:27411026

  8. Epitaxy-assisted creation of PCBM nanocrystals and its application in constructing optimized morphology for bulk-heterojunction polymer solar cells.

    Science.gov (United States)

    Li, Ligui; Lu, Guanghao; Li, Sijun; Tang, Haowei; Yang, Xiaoniu

    2008-12-11

    PCBM (a C60 derivative) is so far the most successful electron acceptor for bulk-heterojunction polymer photovoltaic (PV) cells. Here we present a novel method epitaxy-assisted creation of PCBM nanocrystals and their homogeneous distribution in the matrix using freshly cleaved mica sheet as the substrate. The highly matched epitaxy relationship between the unit cell of PCBM crystal and crystallographic (001) surface of mica induces abundant PCBM nuclei, which subsequently develop into nanoscale crystals with homogeneous dispersion in the composite film. Both the shape and size of these nanocrystals could be tuned via choosing the type of matrix polymer, film thickness, ratio of PCBM in the composite film, and annealing temperature. Thus, the obtained thin composite film is removed from the original mica substrate via the flotation technique and transferred to a real substrate for device completion. The success of this method has been verified by the substantially improved device performance, in particular the increased short-circuit current, which is heavily dependent on the morphology of the photoactive layer. Therefore, we have actually demonstrated a novel approach to construct preferred morphology for high-performance optoelectronic devices via resorting to other specific substrates which could induce the formation of this type morphology. PMID:19367916

  9. FINAL REPORT. SENSORS USING MOLECULAR RECOGNITION IN LUMINESCENT, CONDUCTIVE POLYMERS

    Science.gov (United States)

    The purpose of this project is to develop sensor technology for detecting specific heavy metal ions, such as transition metals, lead, lanthanides, and actinides in waste streams. The sensing strategy uses molecular recognition of the metal ions by polymers that change their lumin...

  10. Proton Conductive Nanosheets Formed by Alignment of Metallo-Supramolecular Polymers.

    Science.gov (United States)

    Pandey, Rakesh K; Rana, Utpal; Chakraborty, Chanchal; Moriyama, Satoshi; Higuchi, Masayoshi

    2016-06-01

    Linear Fe(II)-based metallo-supramolecular polymer chains were precisely aligned by the simple replacement of the counteranion with an N,N'-bis(4-benzosulfonic acid)perylene-3,4,9,10-tetracarboxylbisimide (PSA) dianion, which linked the polymer chains strongly. A parallel alignment of the polymer chains promoted by the PSA dianions yielded nanosheets formation. The nanosheets' structure was analyzed with FESEM, HRTEM, UV-vis, and XRD in detail. The nanosheets showed more than 5 times higher proton conductivity than the original polymer due to the smooth ionic conduction through the aligned polymer chains. The complex impedance plot with two semicircles also suggested the presence of grain boundaries in the polymer nanosheets. PMID:27164027

  11. Molecular motion in polymer electrolytes. An investigation of methods for improving the conductivity of solid polymer electrolytes

    CERN Document Server

    Webster, M I

    2002-01-01

    Three methods were explored with a view to enhancing the ionic conductivity of polymer electrolytes; namely the addition of an inert, inorganic filler, the addition of a plasticizer and the incorporation of the electrolyte in the pores of silica matrices. There have been a number of reports, which suggest the addition of nanocrystalline oxides to polymer electrolytes increases the ionic conductivities by about a factor of two. In this thesis studies of the polymer electrolyte NaSCN.P(EO) sub 8 with added nanocrystalline alumina powder are reported which show no evidence of enhanced conductivity. The addition of a plasticizer to polymer electrolytes will increase the ionic conductivity. A detailed study was made of the polymer electrolytes LiT.P(EO) sub 1 sub 0 and LiClO sub 4.P(EO) sub 1 sub 0 with added ethylene carbonate plasticizer. The conductivities showed an enhancement, however this disappeared on heating under vacuum. The present work suggests that the plasticised system is not thermodynamically stabl...

  12. Electrochemical deposition of conducting polymer coatings on magnesium surfaces in ionic liquid

    OpenAIRE

    Luo, Xiliang; Cui, Xinyan Tracy

    2010-01-01

    A conducting polymer based smart coating for magnesium (Mg) implants that can both improve the corrosion resistance of Mg and release drug in a controllable way is reported. As the ionic liquid is a highly conductive and stable solvent with a very wide electrochemical window, the conducting polymer coatings can be directly electrodeposited on the active metal Mg in ionic liquid at mild conditions, and Mg is considerably stable during the electrodeposition. The electrodeposited Poly(3,4-ethyle...

  13. Electrochemical Switching of Conductance with Diarylethene-Based Redox-Active Polymers

    DEFF Research Database (Denmark)

    Logtenberg, Hella; van der Velde, Jasper H. M.; de Mendoza, Paula;

    2012-01-01

    Reversible switching of conductance using redox triggered switching of a polymer-modified electrode is demonstrated. A bifunctional monomer comprising a central electroswitchable core and two bithiophene units enables formation of a film through anodic electropolymerization. The conductivity of t...... of the polymer can be switched electrochemically in a reversible manner by redox triggered opening and closing of the diarylethene unit. In the closed state, the conductivity of the modified electrode is higher than in the open state....

  14. Highly Electrically Conductive Nanocomposites Based on PolymerInfused Graphene Sponges

    OpenAIRE

    Yuanqing Li; Yarjan Abdul Samad; Kyriaki Polychronopoulou; Alhassan, Saeed M.; Kin Liao

    2014-01-01

    Conductive polymer composites require a threedimensional 3D network to impart electrical conductivity. A general method that is applicable to most polymers for achieving a desirable graphene 3D network is still a challenge. We have developed a facile technique to fabricate highly electrical conductive composite using vacuumassisted infusion of epoxy into graphene sponge GS scaffold. Macroscopic GSs were synthesized from graphene oxide solution by a hydrothermal method combined with freeze dry...

  15. Investigation of ITO free transparent conducting polymer based electrode

    Science.gov (United States)

    Sharma, Vikas; Sapna, Sachdev, Kanupriya

    2016-05-01

    The last few decades have seen a significant improvement in organic semiconductor technology related to solar cell, light emitting diode and display panels. The material and structure of the transparent electrode is one of the major concerns for superior performance of devices such as OPV, OLED, touch screen and LCD display. Commonly used ITO is now restricted due to scarcity of indium, its poor mechanical properties and rigidity, and mismatch of energy levels with the active layer. Nowadays DMD (dielectric-metal-dielectric) structure is one of the prominent candidates as alternatives to ITO based electrode. We have used solution based spin coated polymer layer as the dielectric layer with silver thin film embedded in between to make a polymer-metal-polymer (PMP) structure for TCE applications. The PMP structure shows low resistivity (2.3 x 10-4Ω-cm), high carrier concentration (2.9 x 1021 cm-3) and moderate transparency. The multilayer PMP structure is characterized with XRD, AFM and Hall measurement to prove its suitability for opto-electronic device applications.

  16. Protecting conductive polymer wire from oxidation using an air-impermeable polyisobutylene coating

    International Nuclear Information System (INIS)

    The decay of the electrical conductivity over time under environmental conditions sets restrictions to some possible technical applications of polymer electronics. We report here that a polyisobutylene (PI) coating can act as a protecting layer that prevents the oxidation of polyaniline by oxygen and thereby increase the lifetime of polymer electronics

  17. An Integrated Laboratory Approach toward the Preparation of Conductive Poly(phenylene vinylene) Polymers

    Science.gov (United States)

    Knoerzer, Timm A.; Balaich, Gary J.; Miller, Hannah A.; Iacono, Scott T.

    2014-01-01

    Poly(phenylene vinylene) (PPV) represents an important class of conjugated, conducting polymers that have been readily exploited in the preparation of organic electronic materials. In this experiment, students prepare a PPV polymer via a facile multistep synthetic sequence with robust spectroscopic evaluation of synthetic intermediates and the…

  18. Regiochemistry of Poly(3-Hexylthiophene): Synthesis and Investigation of a Conducting Polymer

    Science.gov (United States)

    Pappenfus, Ted M.; Hermanson, David L.; Kohl, Stuart G.; Melby, Jacob H.; Thoma, Laura M.; Carpenter, Nancy E.; Filho, Demetrio A. da Silva; Bredas, Jean-Luc

    2010-01-01

    A series of experiments for undergraduate laboratory courses (e.g., organic, polymer, inorganic) have been developed. These experiments focus on understanding the regiochemistry of the conducting polymer poly(3-hexylthiophene) (P3HT). The substitution patterns in P3HTs control their conformational features, which, in turn, dictates the [pi]…

  19. Effect of plasticizer and fumed silica on ionic conductivity behaviour of proton conducting polymer electrolytes containing HPF6

    Indian Academy of Sciences (India)

    Jitender Paul Sharma; S S Sekhon

    2013-08-01

    The effect of addition of propylene carbonate (PC) and nano-sized fumed silica on the ionic conductivity behaviour of proton conducting polymer electrolytes containing different concentrations of hexafluorophosphoric acid (HPF6) in polyethylene oxide (PEO) has been studied. The addition of PC results in an increase in ionic conductivity, whereas the addition of nano-sized fumed silica improves mechanical strength of electrolytes along with a small increase in ionic conductivity. It was observed that the simultaneous addition of PC and fumed silica results in electrolytes with optimum value of ionic conductivity and other properties.

  20. An all-polymer micropump based on the conductive polymer poly(3,4-ethylenedioxythiophene) and a polyurethane channel system

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; West, Keld; Hassager, Ole;

    2007-01-01

    An all-polymer micropunlp was realized using the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDT) as the active cODlponent. The pUlnping effect originated fronl an ac potential applied to an aSylnlnetric array of interdigitat.ed electrodes. The PEDT electrodes were fabricated using opti...... of t.he conducting polylner electrodes by an insulating polYlTIer layer prevented electrode break-down at the cost of puolping efficiency. Continuous punlping for 40 nlin at 20 fJ..,m s-l without detectable pump degradation was delTIOnstrated in this configuration....

  1. BF3-doped polyaniline: A novel conducting polymer

    Indian Academy of Sciences (India)

    Debangshu Chaudhuri; D D Sarma

    2006-07-01

    We review the unusual structural, transport and magnetic properties of highly conducting polyaniline, doped with boron trifluoride. Our studies establish the unique conducting state of this system, which is in distinct contrast with the conventional proton-doped polyaniline samples.

  2. Electrically conducting polymer nanostructures confined in anodized aluminum oxide templates (AAO

    Directory of Open Access Journals (Sweden)

    I. Blaszczyk-Lezak

    2016-03-01

    Full Text Available Intrinsically or extrinsically conducting polymers are considered good candidates for replacement of metals in specific applications. In order to further expand their applications, it seems necessary to examine the influence of confinement effects on the electric properties of nanostructured conducting polymers in comparison to the bulk. The present study reports a novel way to fabricate and characterize high quality and controllable one-dimensional (1D polymer nanostructures with promising electrical properties, with the aid of two examples polyaniline (PANI and poly(vinylidene fluoride with multiwall carbon nanotubes (PVDF-MWCNT as representative of intrinsically and extrinsically conducting polymers, respectively. In this work, porous anodic aluminum oxide (AAO templates have been used both as a nanoreactor to synthesize 1D PANI nanostructures by polymerization of the ANI monomer and as a nanomold to prepare 1D PVDFMWCNT nanorods by melt infiltration of the precursor PVDF-MWCNT film. The obtained polymer nanostructures were morphologically and chemically characterized by SEM and Confocal Raman Spectroscopy, respectively, and the electrical properties determined by Broadband Dielectric Spectroscopy (BDS in a non-destructive way. SEM study allowed to establish the final nanostructure of PANI and PVDF-MWCNT and confirmed, in both cases, the well-aligned and uniform rodlike polymer nanostructures. Confocal Raman Microscopy has been performed to study the formation of the conducting emeraldine salt of PANI through all the length of AAO nanocavities. Finally, the electrical conductivity of both types of polymer nanostructures was easily evaluated by means of Dielectric Spectroscopy.

  3. Porous polymer electrolytes with high ionic conductivity and good mechanical property for rechargeable batteries

    Science.gov (United States)

    Liang, Bo; Jiang, Qingbai; Tang, Siqi; Li, Shengliang; Chen, Xu

    2016-03-01

    Porous polymer electrolytes (PPEs) are attractive for developing lithium-ion batteries because of the combined advantages of liquid and solid polymer electrolytes. In the present study, a new porous polymer membrane doped with phytic acid (PA) is prepared, which is used as a crosslinker in polymer electrolyte matrix and can also plasticize porous polymer electrolyte membranes, changing them into soft tough flexible materials. A PEO-PMMA-LiClO4-x wt.% PA (x = weight of PA/weight of polymer, PEO: poly(ethylene oxide); PMMA: poly(methyl methacrylate)) polymer membrane is prepared by a simple evaporation method. The effects of the ratio of PA to PEO-PMMA on the properties of the porous membrane, including morphology, porous structure, and mechanical property, are systematically studied. PA improves the porous structure and mechanical properties of polymer membrane. The maximum tensile strength and elongation of the porous polymer membranes are 20.71 MPa and 45.7% at 15 wt.% PA, respectively. Moreover, the PPEs with 15 wt.% PA has a conductivity of 1.59 × 10-5 S/cm at 20 °C, a good electrochemical window (>5 V), and a low interfacial resistance. The results demonstrate the compatibility of the mechanical properties and conductivity of the PPEs, indicating that PPEs have good application prospects for lithium-ion batteries.

  4. Photo-induced charge transfer and relaxation of persistent charge carriers in polymer/nanocrystal composites for applications in hybrid solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, Marc Daniel; Zutz, Folker; Kolny-Olesiak, Joanna; Borchert, Holgert; Riedel, Ingo; Parisi, Juergen [University of Oldenburg, Department of Physics, Energy and Semiconductor Research Laboratory, Oldenburg (Germany); Maydell, Karsten von [EWE Research Center for Energy Technology, Oldenburg (Germany)

    2009-12-09

    The photo-induced charge transfer and the dynamics of persistent charge carriers in blends of semiconducting polymers and nanocrystals are investigated. Regioregular poly(3-hexylthiophene) (P3HT) is used as the electron donor material, while the acceptor moiety is established by CdSe nanocrystals (nc-CdSe) prepared via colloidal synthesis. As a reference system, organic blends of P3HT and [6,6]-phenyl C{sub 61}-butyric acid methyl ester (PCBM) are studied as well. The light-induced charge transfer between P3HT and the acceptor materials is studied by photoluminescence (PL), photo-induced absorption (PIA) and light-induced electron spin resonance spectroscopy (LESR). Compared to neat P3HT samples, both systems show an intensified formation of polarons in the polymer upon photo-excitation, pointing out successful separation of photogenerated charge carriers. Additionally, relaxation of the persistent charge carriers is investigated, and significant differences are found between the hybrid composite and the purely organic system. While relaxation, reflected in the transient signal decay of the polaron signal, is fast in the organic system, the hybrid blends exhibit long-term persistence. The appearance of a second, slow recombination channel indicates the existence of deep trap states in the hybrid system, which leads to the capture of a large fraction of charge carriers. A change of polymer conformation due to the presence of nc-CdSe is revealed by low temperature LESR measurements and microwave saturation techniques. The impact of the different recombination behavior on the photovoltaic efficiency of both systems is discussed. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  5. Tailoring Thermal Conductivity of Single-stranded Carbon-chain Polymers through Atomic Mass Modification

    CERN Document Server

    Liao, Quanwen; Liu, Zhichun; Liu, Wei

    2016-01-01

    Tailoring the thermal conductivity of polymers is central to enlarge their applications in the thermal management of flexible integrated circuits. Progress has been made over the past decade by fabricating materials with various nanostructures, but a clear relationship between various functional groups and thermal properties of polymers remains to be established. Here, we numerically study the thermal conductivity of single-stranded carbon-chain polymers with multiple substituents of hydrogen atoms through atomic mass modification. We find that their thermal conductivity can be tuned by atomic mass modifications as revealed through molecular dynamics simulations. The simulation results suggest that heavy homogeneous substituents do not assist heat transport and trace amounts of heavy substituents can in fact hinder heat transport substantially. Our analysis indicates that carbon chain has the biggest contribution (over 80%) to the thermal conduction in single-stranded carbon-chain polymers. We further demonst...

  6. Cotton Fabric Coated with Conducting Polymers and its Application in Monitoring of Carnivorous Plant Response.

    Science.gov (United States)

    Bajgar, Václav; Penhaker, Marek; Martinková, Lenka; Pavlovič, Andrej; Bober, Patrycja; Trchová, Miroslava; Stejskal, Jaroslav

    2016-01-01

    The paper describes the electrical plant response to mechanical stimulation monitored with the help of conducting polymers deposited on cotton fabric. Cotton fabric was coated with conducting polymers, polyaniline or polypyrrole, in situ during the oxidation of respective monomers in aqueous medium. Thus, modified fabrics were again coated with polypyrrole or polyaniline, respectively, in order to investigate any synergetic effect between both polymers with respect to conductivity and its stability during repeated dry cleaning. The coating was confirmed by infrared spectroscopy. The resulting fabrics have been used as electrodes to collect the electrical response to the stimulation of a Venus flytrap plant. This is a paradigm of the use of conducting polymers in monitoring of plant neurobiology. PMID:27070612

  7. Cotton Fabric Coated with Conducting Polymers and its Application in Monitoring of Carnivorous Plant Response

    Science.gov (United States)

    Bajgar, Václav; Penhaker, Marek; Martinková, Lenka; Pavlovič, Andrej; Bober, Patrycja; Trchová, Miroslava; Stejskal, Jaroslav

    2016-01-01

    The paper describes the electrical plant response to mechanical stimulation monitored with the help of conducting polymers deposited on cotton fabric. Cotton fabric was coated with conducting polymers, polyaniline or polypyrrole, in situ during the oxidation of respective monomers in aqueous medium. Thus, modified fabrics were again coated with polypyrrole or polyaniline, respectively, in order to investigate any synergetic effect between both polymers with respect to conductivity and its stability during repeated dry cleaning. The coating was confirmed by infrared spectroscopy. The resulting fabrics have been used as electrodes to collect the electrical response to the stimulation of a Venus flytrap plant. This is a paradigm of the use of conducting polymers in monitoring of plant neurobiology. PMID:27070612

  8. Cotton Fabric Coated with Conducting Polymers and its Application in Monitoring of Carnivorous Plant Response

    Directory of Open Access Journals (Sweden)

    Václav Bajgar

    2016-04-01

    Full Text Available The paper describes the electrical plant response to mechanical stimulation monitored with the help of conducting polymers deposited on cotton fabric. Cotton fabric was coated with conducting polymers, polyaniline or polypyrrole, in situ during the oxidation of respective monomers in aqueous medium. Thus, modified fabrics were again coated with polypyrrole or polyaniline, respectively, in order to investigate any synergetic effect between both polymers with respect to conductivity and its stability during repeated dry cleaning. The coating was confirmed by infrared spectroscopy. The resulting fabrics have been used as electrodes to collect the electrical response to the stimulation of a Venus flytrap plant. This is a paradigm of the use of conducting polymers in monitoring of plant neurobiology.

  9. Synthesis and Ionic Conductivity of Network Polymer Electrolytes with Internal Plasticizers

    Institute of Scientific and Technical Information of China (English)

    Jun Jie KANG; Shi Bi FANG

    2004-01-01

    Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.

  10. BIOAFFINITY SENSORS BASED ON CONDUCTING POLYMERS: A SHORT REVIEW. (R825323)

    Science.gov (United States)

    The development of new electrode materials has expanded the range and classes of detectable compounds using electroanalytical methods. Conducting electroactive polymers (CEPs) have been demonstrated to have remarkable sensing applications through their ability to be reversibly ox...

  11. ION AND MOLECULE SENSORS USING MOLECULAR RECOGNITION IN LUMINESCENT, CONDUCTIVE POLYMERS

    Science.gov (United States)

    This program integrates three individual, highly interactive projects that will use molecular recognition strategies to develop sensor technology based on luminescent, conductive polymers that contain sites for binding specific molecules or ions in the presence of related molecul...

  12. Water-free Alkaline Polymer-inorganic Acid Complexes with High Conductivity at Ambient Temperature

    Institute of Scientific and Technical Information of China (English)

    O.V.Chervakov; M.V.Andriianova; V.V.Riabenko; A.V.Markevich; E.M.Shembel; D.Meshri

    2007-01-01

    1 Results Recently increased interest is shown to proton conducting materials based on the alkaline polymer-inorganic acid complexes that is caused by a possibility of their application as the high-temperature electrolyte systems for various electrochemical devices (fuel cells,sensors,lithium power sources etc.).Complexes of inorganic acids with the alkaline polymers (polybenzimidazoles[1],polyvinylpyridines[2]) are characterized by high ionic conductivity at ambient temperatures (up to 10-2 Ω-1·cm-1) a...

  13. Reversible post-breakdown conduction in aluminum oxide-polymer capacitors

    OpenAIRE

    CHEN, Qian; Gomes, HL; Rocha, PRF; De Leeuw,; Meskers, SCJ Stefan

    2013-01-01

    Aluminum/Al2O3/polymer/metal capacitors submitted to a low-power constant current stress undergo dielectric breakdown. The post-breakdown conduction is metastable, and over time the capacitors recover their original insulating properties. The decay of the conduction with time follows a power law (1/t) α . The magnitude of the exponent α can be raised by application of an electric field and lowered to practically zero by optical excitation of the polyspirofluorene polymer. The metastable condu...

  14. A unified model for temperature dependent electrical conduction in polymer electrolytes

    OpenAIRE

    Mikrajuddin; Lenggoro, I. Wuled; Okuyama, Kikuo

    2001-01-01

    The observed temperature dependence of electrical conduction in polymer electrolytes is usually fitted with two separated equations: an Arrhenius equation at low temperatures and Vogel-Tamman-Fulcher (VTF) at high temperatures. We report here a derivation of a single equation to explain the variation of electrical conduction in polymer electrolytes at all temperature ranges. Our single equation is in agreement with the experimental data

  15. DOPANT FLEXIBILITY AND PROCESSABILITY STUDIES WITH ELECTRICALLY CONDUCTIVE, FACE-TO-FACE METALLOMACROCYCLIC POLYMERS

    OpenAIRE

    Inabe, T.; Lyding, J.; Moguel, M.; Marks, T.

    1983-01-01

    In doping experiments on the cofacially arrayed phthalocyanine polymer [Si(Pc)O]n using high potential quinone, halogen, or nitrosyl electron acceptors, the achievable degree of partial oxidation, the inhomogeneity of the doping process, and the conductivity mechanism remain remarkably constant. Using wet spinning techniques, it has proven possible to prepare electrically conductive fibers of [Si(Pc)O]n alone or blended with the high performance aramid polymer Kevlar.

  16. Electrochemical evaluation of the p-Si/conducting polymer interfacial properties

    Science.gov (United States)

    Nagasubramanian, G.; Distefano, S.; Moacanin, J.

    1988-01-01

    Results are presented from an experimental investigation of the contact resistance and interfacial properties of a p-Si/conducting polymer interface for solar cell applications. The electronic character of the polymer/semiconductor function is determined by studying the electrochemical behavior of both poly(isothianapthene) (PITN) and polypyrrole (PP) in an acetonitrile solution on p-silicon electrodes. The results obtained indicate that while PITN is intrinsically more conductive than PP, neither passivates surface states nor forms ohmic contact.

  17. Properties and processing by extrusion of electrically conductive multilayer filaments comprising polymer composites

    OpenAIRE

    R. S. Martins; Gonçalves, Renato Ferreira; Azevedo, Tiago; Nóbrega, J. M.; Carvalho, Helder; Lanceros-Méndez, S.; Rocha, J. G.

    2013-01-01

    This work describes the production and characterization of three-layer piezoelectric filaments using two different electrically conductive polymers. The filaments were produced in a filament extrusion line, equipped with a coextrusion die that enabled a coaxial arrangement for a three-layer filament. For the inner and outer layers two different electrically conductive compounds were used, and the middle layer was made of the electroactive polymer PVDF. The produced filament can be used as a p...

  18. Micropatterning of Functional Conductive Polymers with Multiple Surface Chemistries in Register

    DEFF Research Database (Denmark)

    Lind, Johan Ulrik; Acikgöz, Canet; Daugaard, Anders Egede;

    2012-01-01

    A versatile procedure is presented for fast and efficient micropatterning of multiple types of covalently bound surface chemistry in perfect register on and between conductive polymer microcircuits. The micropatterning principle is applied to several types of native and functionalized PEDOT (poly...... functionalized conjugated polymer systems.......A versatile procedure is presented for fast and efficient micropatterning of multiple types of covalently bound surface chemistry in perfect register on and between conductive polymer microcircuits. The micropatterning principle is applied to several types of native and functionalized PEDOT (poly(3...

  19. Poly(bis- (2,5-N-methyl pyrrylene) vinylene), a new conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Takassi, M.A.; Wha Chen; Niziurski, R.E.; Cava, M.P.; Metzger, R.M. (Dept. of Chemistry, Univ. of Alabama, Tuscaloosa, AL (USA))

    1990-05-01

    A new conducting polymer, poly(bis-(2,5-N-methylpyrrylene)vinylene), pMPy2V, has been prepared by electrochemical oxidation; it is an air-stable, moisture-insensitive, free-standing, black film with metallic conductivity 500 to 800 times greater than that of poly(N-methylpyrrole). The doped polymer probably has a trans configuration around the vinylene groups, and has approximately one cation site for every 16 neutral N-methylpyrrole units. The polymer can be electrochemically reduced to the yellow insulating form. (orig.).

  20. Conductive network formation of carbon nanotubes in elastic polymer microfibers and its effect on the electrical conductance: Experiment and simulation.

    Science.gov (United States)

    Cho, Hyun Woo; Kim, Sang Won; Kim, Jeongmin; Kim, Un Jeong; Im, Kyuhyun; Park, Jong-Jin; Sung, Bong June

    2016-05-21

    We investigate how the electrical conductance of microfibers (made of polymers and conductive nanofillers) decreases upon uniaxial deformation by performing both experiments and simulations. Even though various elastic conductors have been developed due to promising applications for deformable electronic devices, the mechanism at a molecular level for electrical conductance change has remained elusive. Previous studies proposed that the decrease in electrical conductance would result from changes in either distances or contact numbers between conductive fillers. In this work, we prepare microfibers of single walled carbon nanotubes (SWCNTs)/polyvinyl alcohol composites and investigate the electrical conductance and the orientation of SWCNTs upon uniaxial deformation. We also perform extensive Monte Carlo simulations, which reproduce experimental results for the relative decrease in conductance and the SWCNTs orientation. We investigate the electrical networks of SWCNTs in microfibers and find that the decrease in the electrical conductance upon uniaxial deformation should be attributed to a subtle change in the topological structure of the electrical network. PMID:27208970

  1. A Route for Polymer Nanocomposites with Engineered Electrical Conductivity and Percolation Threshold

    Directory of Open Access Journals (Sweden)

    Lawrence T. Drzal

    2010-02-01

    Full Text Available Polymer nanocomposites with engineered electrical properties can be made by tuning the fabrication method, processing conditions and filler’s geometric and physical properties. This work focuses on investigating the effect of filler’s geometry (aspect ratio and shape, intrinsic electrical conductivity, alignment and dispersion within the polymer, and polymer crystallinity, on the percolation threshold and electrical conductivity of polypropylene based nanocomposites. The conductive reinforcements used are exfoliated graphite nanoplatelets, carbon black, vapor grown carbon fibers and polyacrylonitrile carbon fibers. The composites are made using melt mixing followed by injection molding. A coating method is also employed to improve the nanofiller’s dispersion within the polymer and compression molding is used to alter the nanofiller’s alignment.

  2. Studies on AC Electrical Conductivity of CdCl2 Doped PVA Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    M. B. Nanda Prakash

    2013-01-01

    Full Text Available PVA-based polymer electrolytes were prepared with various concentrations of CdCl2 using solvent casting method. Prepared polymer films were investigated using line profile analysis employing X-ray diffraction (XRD data. XRD results show that the crystallite size decreases and then increases with increase in CdCl2. AC conductivity in these polymer increases films first and then decreases. These observations are in agreement with XRD results. The highest ionic conductivity of 1.68E − 08 Scm−1 was observed in 4% of CdCl2 in PVA polymer blend. Crystallite ellipsoids for different concentrations of CdCl2 are computed here using whole pattern powder fitting (WPPF indicating that crystallite area decreases with increase in the ionic conductivity.

  3. Superior thermal conductivity of polymer nanocomposites by using graphene and boron nitride as fillers

    Science.gov (United States)

    Liem, H.; Choy, H. S.

    2013-06-01

    We report a significant enhancement of thermal conductivity in polymer nanocomposites with graphene and boron nitride as fillers. Strong variations in the Raman spectra for different single-layer graphene flakes are related to the measured thermal conductivity in polymer nanocomposites. In the absence of doping, variations in the Raman parameters are most common, suggesting the presence of excess charges in the samples. Graphene has a Raman D-peak that indicates structural disorder is present, causing the large variations in Raman G peaks. Using this type of graphene and boron nitride for preparing the polymer nanocomposites, the thermal conductivities of the polymer nanocomposites are measured to be in the range of 6.2-9.5 W/mK. The absence of Raman D peaks suggests that structural defects are infinitesimal and the graphene is pristine. Polymer nanocomposites filled with graphene without a D-peak exhibit thermal conductivities as high as ˜21.6 W/mK. As a thermal management material, thermal imaging shows that the polymer nanocomposite can effectively lower the surface mounted LED temperature by 21.1 °C. The existence of Raman D peaks can be used to distinguish two different types of graphenes, establishing the primary prerequisite for achieving a higher thermal conductivity.

  4. Improving conducting polymer electrochromic speeds and depositing aligned polymeric nanofibers by electrospinning process

    Science.gov (United States)

    Asemota, Chris I.

    The effects of film thickness and porosity on electrochromic switching time of conducting polymers was pursued to determine the morphology influence on ions transport during oxidation step of the redox process, affording sub-second or seconds switching times. Electrospinning technique provided non-woven nanofiber mats, while spin coating and electropolymerization of monomer (N3T) provided films. Porosity decreased as depositing method changed from electrospinning to spin coating. In electrochemical oxidation, the electrons leave the polymer at the metal electrode-polymer film interface, and counter ions arrive at the polaron-bipolaron sites left in the polymer, through polymer-electrolyte interface. Counter ion diffusion in conducting polymers are film thickness limited at increasing thickness and inability of ions to reach holes sites on the oxidizing polymer accounts for long switching speeds, introducing extensive and micro pores and high surface areas should lead to decreasing electrochromic switching speed to single digit time in seconds (for display and vision applications), while increasing the maximum optical switching contrast due to increased fiber mat thicknesses. Photolithographic patterning of nanofiber mats of the conducting polymer precursor having photo cross-linking unit was also explored. The photo-crosslinkable polymer was prepared by including norborene methacrylate (NMA) units to the polymer backbone during precursor polymerization, yielding a terpolymer poly(N3T-NA-NMA). The influence of photo crosslinking on electrochemical switching in conducting polymer nanofibers, and effect of developing parameters (solvent and time) on pattern transfer to the nanofiber mat was investigated and showed no influence on the electrochemical redox of the polymer. Solvents suitable for dissolving the polymer were investigated as developers with results showing non-differentiable pattern transfer for all suitable solvents, and no net preference to solvent choice

  5. Conductive polymers for controlled release and treatment of central nervous system injury

    Science.gov (United States)

    Saigal, Rajiv

    As one of the most devastating forms of neurotrauma, spinal cord injury remains a challenging clinical problem. The difficulties in treatment could potentially be resolved by better technologies for therapeutic delivery. In order to develop new approaches to treating central nervous system injury, this dissertation focused on using electrically-conductive polymers, controlled drug release, and stem cell transplantation. We first sought to enhance the therapeutic potential of neural stem cells by electrically increasing their production of neurotrophic factors (NTFs), important molecules for neuronal cell survival, differentiation, synaptic development, plasticity, and growth. We fabricated a new cell culture device for growing neural stem cells on a biocompatible, conductive polymer. Electrical stimulation via the polymer led to upregulation of NTF production by neural stem cells. This approach has the potential to enhance stem cell function while avoiding the pitfalls of genetic manipulation, possibly making stem cells more viable as a clinical therapy. Seeing the therapeutic potential of conductive polymers, we extended our studies to an in vivo model of spinal cord injury (SCI). Using a novel fabrication and extraction technique, a conductive polymer was fabricated to fit to the characteristic pathology that follows contusive SCI. Assessed via quantitative analysis of MR images, the conductive polymer significantly reduced compression of the injured spinal cord. Further characterizing astroglial and neuronal response of injured host tissue, we found significant neuronal sparing as a result of this treatment. The in vivo studies also demonstrated improved locomotor recovery mediated by a conductive polymer scaffold over a non-conductive control. We next sought to take advantage of conductive polymers for local, electronically-controlled release of drugs. Seeking to overcome reported limitations in drug delivery via polypyrrole, we first embedded drugs in poly

  6. A study on nanocomposites made of a conducting polymer and metallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed Ahmed Khalil, Rania [Nanochemistry and Nanoengineering, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University of Kiel (Germany); Multicomponent Materials, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University of Kiel (Germany); Abdelaziz Mahmoud Abdelaziz, Ramzy [Nanochemistry and Nanoengineering, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University of Kiel (Germany); Strunkus, Thomas; Faupel, Franz [Multicomponent Materials, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University of Kiel (Germany); Elbahri, Mady [Nanochemistry and Nanoengineering, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-University of Kiel (Germany); Helmholtz-Zentrum Geesthacht GmbH, Institute of Polymer Research, Nanochemistry and Nanoengineering (Germany)

    2011-07-01

    Conducting polymers offer a unique combination of properties that makes them attractive materials for many electronic applications. PEDOT:PSS is one of the most successful conductive materials which is considered to be highly stable and resisting degradation under typical ambient conditions. In this study, we have prepared two sets of conducting polymer nano-composites. The first set is composed of PEDOT:PSS doped with different aspect ratios of gold nanorod and the other one is PEDOT:PSS doped with different sizes of gold nanosphere. The chemical reduction method was used for preparing the nano-particles. Indeed, gold nanorods and nanosphere which exhibit tunable absorption as a function of their size and aspect ratio, respectively, have tuned the absorption coefficient for PEDOT: PSS. The nature of the dopant as well as the degree of doping has played a significant role in the improvement of the electrical conductivity of conducting polymer.

  7. Shrinkage Effects of the Conduction Zone in the Electrical Properties of Metal Oxide Nanocrystals: The Basis for Room Temperature Conductometric Gas Sensor

    Directory of Open Access Journals (Sweden)

    M. Manzanares

    2009-01-01

    Full Text Available The influence of charge localized at the surface of minute metal oxide nanocrystals was studied in WO3 and In2O3 nanostructures, which were obtained replicating mesoporous silica templates. Here, it is shown that the very high resistive states observed at room temperature and dark conditions were originated by the total shrinkage of the conductive zone in the inner part of these nanocrystals. On the contrary, at room temperature and under UV illumination, both photogenerated electron-hole pairs and empty surface states generated by photons diminished the negative charge accumulated at the surface, enlarging the conductive zone and, as a consequence, leading to a reduction of the electrical resistance. Under these conditions, empty surface states produced by UV light reacted with oxidizing gaseous molecules. The charge exchange associated to these reactions also affected the size of the inner conductive zone, and leaded to a new steady-state resistance. These chemical, physical and geometrical effects can be used for gas detection, and constitutes the basis for developing novel room temperature conductometric gas sensors responsive to oxidizing species.

  8. Investigating the Inter-Tube Conduction Mechanism in Polycarbonate Nanocomposites Prepared with Conductive Polymer-Coated Carbon Nanotubes

    Science.gov (United States)

    Ventura, Isaac Aguilar; Zhou, Jian; Lubineau, Gilles

    2015-12-01

    A well-known strategy to improve the electrical conductivity of polymers is to dope them with high-aspect-ratio and conductive nanoparticles such as carbon nanotubes (CNTs). However, these nanocomposites also exhibit undesirable properties such as damage-sensitive and history-dependent conductivity because their macroscopic electrical conductivity is largely determined by the tunneling effect at the tube/tube interface. To reduce these issues, new nanocomposites have been developed with CNTs that have been coated with a conductive layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS). It has been posited that the insulating region between the CNTs is replaced by a conductive polymer bridge; this has not been proven up to now. We propose here to investigate in-depth how the macroscopic conductivity of these materials is changing when (1) varying the frequency of the electrical loading (impedance spectroscopy), (2) varying the mechanical hydrostatic pressure, and (3) varying the voltage of the electrical loading. The response is systematically compared to the one of conventional carbon nanotube/polycarbonate (CNT/PC) nanocomposites so we can clarify how efficiently the tunneling effect is suppressed from these composites. The objective is to elucidate further the mechanism for conduction in such material formulations.

  9. Investigating the Inter-Tube Conduction Mechanism in Polycarbonate Nanocomposites Prepared with Conductive Polymer-Coated Carbon Nanotubes

    KAUST Repository

    Ventura, Isaac Aguilar

    2015-12-16

    A well-known strategy to improve the electrical conductivity of polymers is to dope them with high-aspect-ratio and conductive nanoparticles such as carbon nanotubes (CNTs). However, these nanocomposites also exhibit undesirable properties such as damage-sensitive and history-dependent conductivity because their macroscopic electrical conductivity is largely determined by the tunneling effect at the tube/tube interface. To reduce these issues, new nanocomposites have been developed with CNTs that have been coated with a conductive layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS). It has been posited that the insulating region between the CNTs is replaced by a conductive polymer bridge; this has not been proven up to now. We propose here to investigate in-depth how the macroscopic conductivity of these materials is changing when (1) varying the frequency of the electrical loading (impedance spectroscopy), (2) varying the mechanical hydrostatic pressure, and (3) varying the voltage of the electrical loading. The response is systematically compared to the one of conventional carbon nanotube/polycarbonate (CNT/PC) nanocomposites so we can clarify how efficiently the tunneling effect is suppressed from these composites. The objective is to elucidate further the mechanism for conduction in such material formulations.

  10. Gain Characteristics of Polymer Waveguide Amplifiers Based on NaYF4:Ybl+, Er3+ Nanocrystals at 0.54 µm Wavelength.

    Science.gov (United States)

    Zhang, Meiling; Yin, Jiao; Jia, Zhixu; Song, Weiye; Wang, Xibin; Qin, Guanshi; Zhao, Dan; Qin, Weiping; Wang, Fei; Zhang, Daming

    2016-04-01

    Gain characteristics of polymer waveguide amplifiers based on NaYF4:Yb3+, Er3+ nanocrystals (NCs) at 0.54 µm wavelength were investigated through numerical simulations. NaYF4:18%Yb3+, 1 0%Er3+ NCs were doped into SU-8 2005 polymer matrix as the core of a polymer waveguide. The absorption spectrum and photoluminescence spectrum of the NCs were recorded and analyzed. The Judd-Ofelt parameters were achieved by means of Judd-Ofelt theory: Ω2 = 6.302 x 10(-20) cm2, Ω4 = 0.69 x 10(-20) cm2, Ω6 =7.572 x 10(-20) cm2. We simulated the gain characteristics of the waveguide amplifier at 0.54 µm wavelength by combining the atomic rate equations with power propaga- tion equations. The gain curves had the saturation effects. A maximum gain -4.3 dB for the 5 cm waveguide with the Er3+ concentration of ~7.5 x 1025 m-3 was obtained.

  11. Varying the apparent conduction mechanism in polymer semiconductors

    Science.gov (United States)

    Bittle, Emily G.; Ro, Hyun Wook; Basham, James I.; Delongchamp, Dean; Gundlach, David; Jurchescu, Oana

    The weak van der Waals inter-molecular interactions in organic semiconductors (OSCs) result in large variations in transport behavior ranging from hopping to band-like. Accurately measuring and modelling charge transport is a prerequisite to establishing robust transport-microstructure correlations and developing predictive structure-function relationships for optimized materials design and processing. Field-effect transistors have become a favored test structure for parameterizing and benchmarking the electronic properties of OSCs due to their ease of fabrication, measurement, and possible use in commercial applications. However, correctly analyzing transistor current-voltage measurements to extract material properties has proven difficult, as parasitic effects influence the device electrical properties and mask intrinsic material properties. Here, we use impedance spectroscopy to evaluate the effects of contacts on device operation and extract the properties of the channel which we compare with conventional DC measurements. We apply this approach to model systems of the widely studied polymer regioregular poly(3-hexylthiophene-2,5-diyl) which we engineer through different solidification kinetics to achieve distinct, well characterized degrees of molecular order. When increasing the order we find that the transport changes from field enhanced to field independent. This study addresses the origins of transport behavior seen in OSCs while discerning non-linear contact effects from field dependent transport.

  12. Role of Chain Morphology and Stiffness in Thermal Conductivity of Amorphous Polymers.

    Science.gov (United States)

    Zhang, Teng; Luo, Tengfei

    2016-02-01

    Designing thermally conductive polymer is of scientific interest and practical importance for applications like thermal interface materials, electronics packing, and plastic heat exchangers. In this work, we study the fundamental relationship between the molecular morphology and thermal conductivity in bulk amorphous polymers. We use polyethylene as a model system and performed systematic parametric study in molecular dynamics simulations. We find that the thermal conductivity is a strong function of the radius of gyration of the molecular chains, which is further correlated to persistence length, an intrinsic property of the molecule that characterizes molecular stiffness. Larger persistence length can lead to more extended chain morphology and thus higher thermal conductivity. Further thermal conductivity decomposition analysis shows that thermal transport through covalent bonds dominates the effective thermal conductivity over other contributions from nonbonded interactions (van der Waals) and translation of molecules disregarding the morphology. As a result, the more extended chains due to larger persistence length provide longer spatial paths for heat to transfer efficiently and thus lead to higher thermal conductivity. In addition, rigid rod-like polymers with very large persistence length tend to spontaneously crystallize and form orientated chains, leading to a thermal conductivity increase by more than 1 order of magnitude. Our results will provide important insights into the design of thermally conductive amorphous polymers.

  13. Role of Chain Morphology and Stiffness in Thermal Conductivity of Amorphous Polymers.

    Science.gov (United States)

    Zhang, Teng; Luo, Tengfei

    2016-02-01

    Designing thermally conductive polymer is of scientific interest and practical importance for applications like thermal interface materials, electronics packing, and plastic heat exchangers. In this work, we study the fundamental relationship between the molecular morphology and thermal conductivity in bulk amorphous polymers. We use polyethylene as a model system and performed systematic parametric study in molecular dynamics simulations. We find that the thermal conductivity is a strong function of the radius of gyration of the molecular chains, which is further correlated to persistence length, an intrinsic property of the molecule that characterizes molecular stiffness. Larger persistence length can lead to more extended chain morphology and thus higher thermal conductivity. Further thermal conductivity decomposition analysis shows that thermal transport through covalent bonds dominates the effective thermal conductivity over other contributions from nonbonded interactions (van der Waals) and translation of molecules disregarding the morphology. As a result, the more extended chains due to larger persistence length provide longer spatial paths for heat to transfer efficiently and thus lead to higher thermal conductivity. In addition, rigid rod-like polymers with very large persistence length tend to spontaneously crystallize and form orientated chains, leading to a thermal conductivity increase by more than 1 order of magnitude. Our results will provide important insights into the design of thermally conductive amorphous polymers. PMID:26751002

  14. Electrical conductivity of polyaniline doped PVC–PMMA polymer blends

    Indian Academy of Sciences (India)

    S H Deshmukh; D K Burghate; V P Akhare; V S Deogaonkar; P T Deshmukh; M S Deshmukh

    2007-02-01

    The electrical conductivity of polyaniline doped polyvinylchloride (PVC) and poly(methyl methacrylate) (PMMA) thin films has been measured by studying the – characteristics at various temperatures in the range 323–363 K. The results are presented in the form of – characteristics and analysis has been made by interpretation of Poole–Frenkel, Fowler–Nordheim, Schottky ln() vs plots, Richardson and Arrhenius plots. The analysis of these results suggests that Schottky and Richardson mechanisms are primarily responsible for the observed conduction.

  15. Printed organic conductive polymers thermocouples in textile and smart clothing applications.

    Science.gov (United States)

    Seeberg, Trine M; Røyset, Arne; Jahren, Susannah; Strisland, Frode

    2011-01-01

    This work reports on an experimental investigation of the potential of using selected commercially available organic conductive polymers as active ingredients in thermocouples printed on textiles. Poly(3, 4-ethylenedioxythiophene): poly(4 styrenesulfonate) (PEDOT:PSS) and polyaniline (PANI) were screen printed onto woven cotton textile. The influence of multiple thermocycles between 235 K (-38 °C) and 350 K (+77 °C) on resistivity and thermoelectric properties was examined. The Seebeck coefficients of PEDOT:PSS and PANI were found to be about +18 μV/K and +15 uV/K, respectively, when "metal-polymer" thermocouples were realized by combining the polymer with copper. When "polymer-polymer" thermocouples were formed by combining PEDOT:PSS and PANI, a thermoelectric voltage of about +10 μV/K was observed. A challenge recognized in the experiments is that the generated voltage exhibited drift and fluctuations. PMID:22255039

  16. Structure-conductivity studies in polymer electrolytes containing multivalent cations

    CERN Document Server

    Aziz, M

    1996-01-01

    force microscopy (AFM). DSC evidences helped to explain the texture of the iron samples during the drying process, and showed transitions between low melting, PEO and high melting spherulites, and VTPM is able to visualise the spherulites present in the samples. AFM has successfully imaged the as cast PEO sub 8 :FeBr sub 2 sample and the surface effect causing extra resistance in the impedance spectra could be seen. Conductivity studies were carried out using a.c. impedance spectra. Fe(ll) samples exhibit the typical semicircle-spike plot but the Fe(lll) samples displayed an extra semicircle before the spike reflecting a surface effect. This is also manifested in the Arrhenius plots of the same samples where a dip was shown at 100 deg C. From the conductivity studies on the iron systems it was found that for the dry samples the optimum conductivity was observed in PEO sub 8 :FeBr sub x irrespective of the valence state of the cation. For the air-cast samples the optimum conductivity composition depends on the...

  17. Thermally stimulated discharge conductivity in polymer composite thin films

    Indian Academy of Sciences (India)

    V S Sangawar; P S Chikhalikar; R J Dhokne; A U Ubale; S D Meshram

    2006-08-01

    This paper describes the results of thermally stimulated discharge conductivity study of activated charcoal–polyvinyl chloride (PVC) thin film thermoelectrets. TSDC has been carried out in the temperature range 308–400°K and at four different polarizing fields. Results are discussed on the basis of mobility of activated charcoal and polyvinyl chloride chains.

  18. Sensing of environmental pollutant by conductive composite from prepared from hyperbranched polymer-grafted carbon black and crystalline polymer

    International Nuclear Information System (INIS)

    Complete text of publication follows. The hyperbranched (HB) polymer-grafted (PG) carbon blacks (CB) have the possibility of utilizing as a support of catalyst and enzyme, and a curing agent of epoxy resin, because they have much terminal amino or hydroxyl groups. The postgrafting of crystalline polymer onto HB PG CB and the sensing of environmental pollutant by the conductive composite prepared from the polymer-postgrafted CB was discussed. The grafting of poly(amidoamide) onto CB surface was achieved by repeating either Michael addition of methyl acrylate to amino group on the surface or the amidation of the resulting terminal methyl ester group with ethylene diamine. HB polyester onto CB surface was grafted by stepwise growth of 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) from surface carboxyl and hydroxyl groups on CB as a core in the presence of p-toluenesulfonic acid (p-TSA). The one-pot grafting of HB polyester onto CB as core was also achieved by the polycondensation of bis-MPA in the presence of p-TSA. Postgrafting of crystalline polymer onto HB polymer-grafted CB was achieved by the reaction of terminal amino or hydroxyl groups of grafted chain with COCl-terminated crystalline polymer. The electric resistance of the composite prepared from crystalline polymer-postgrafted CB was found to increase drastically in hexane, containing environmental pollutant, such as chloroform and trichloroethane, and returned immediately to the initial resistance when it was transferred into pure hexane. Based on the above results, it is concluded that the composite can be used as a novel sensor for environmental pollutant in solution

  19. Functionalization of conducting polymer with novel Co(II) complex: Electroanalysis of ascorbic acid

    International Nuclear Information System (INIS)

    We report for the first time the functionalization of a conducting polymer with a metal complex in order to develop a new type of catalytic material exhibiting better electronic communication through their delocalized π electrons. The Co(II) complex having hydroxyl group as functional moiety is chemically coupled with carboxyl group of polyanthranilic acid which itself is a self doped conducting polymer. The covalent linkage between Co(II) and -OH group is confirmed using UV-vis, FT-IR and NMR spectroscopic techniques. The Co(II) complex functionalized polymer does exhibit excellent redox behavior and stability with mixed properties of Co(II) complex and π-conjugated polymer. The material possesses potential benefits in sensors/biosensor applications and it is demonstrated for the electroanalysis of ascorbic acid at a level of nano molar concentration.

  20. Kinetic factors determining conducting filament formation in solid polymer electrolyte based planar devices.

    Science.gov (United States)

    Krishnan, Karthik; Aono, Masakazu; Tsuruoka, Tohru

    2016-08-01

    Resistive switching characteristics and conducting filament formation dynamics in solid polymer electrolyte (SPE) based planar-type atomic switches, with opposing active Ag and inert Pt electrodes, have been investigated by optimizing the device configuration and experimental parameters such as the gap distance between the electrodes, the salt inclusion in the polymer matrix, and the compliance current applied in current-voltage measurements. The high ionic conductivities of SPE enabled us to make scanning electron microscopy observations of the filament formation processes in the sub-micrometer to micrometer ranges. It was found that switching behaviour and filament growth morphology depend strongly on several kinetic factors, such as the redox reaction rate at the electrode-polymer interfaces, ion mobility in the polymer matrix, electric field strength, and the reduction sites for precipitation. Different filament formations, resulting from unidirectional and dendritic growth behaviours, can be controlled by tuning specified parameters, which in turn improves the stability and performance of SPE-based devices.

  1. Functionalization of conducting polymer with novel Co(II) complex: Electroanalysis of ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, Swati [School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India); Prakash, Rajiv, E-mail: rajivprakash12@yahoo.com [School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)

    2010-06-15

    We report for the first time the functionalization of a conducting polymer with a metal complex in order to develop a new type of catalytic material exhibiting better electronic communication through their delocalized {pi} electrons. The Co(II) complex having hydroxyl group as functional moiety is chemically coupled with carboxyl group of polyanthranilic acid which itself is a self doped conducting polymer. The covalent linkage between Co(II) and -OH group is confirmed using UV-vis, FT-IR and NMR spectroscopic techniques. The Co(II) complex functionalized polymer does exhibit excellent redox behavior and stability with mixed properties of Co(II) complex and {pi}-conjugated polymer. The material possesses potential benefits in sensors/biosensor applications and it is demonstrated for the electroanalysis of ascorbic acid at a level of nano molar concentration.

  2. Ion Conductive Polymer Electrolyte Membranes and Simulation of Their Fractal Growth Patterns

    International Nuclear Information System (INIS)

    Due to their high ionic conductivity, solid polymer electrolyte (SPE) systems have attracted wide spread attention as the most appropriate choice to fabricate all-solid-state electrochemical devices, namely batteries, sensors and fuel cells. In this work, ion conductive polymer electrolyte membranes have been prepared for battery fabrication. However, fractals were found to grow in these polymer electrolyte membranes weeks after they were prepared. It was believed that the formation of fractal aggregates in these membranes were due to ionic movement. The discovery of fractal growth pattern can be used to understand the effects of such phenomenon in the polymer electrolyte membranes. Digital images of the fractal growth patterns were taken and a simulation model was developed based on the Brownian motion theory and a fractal dialect known as L-system. A computer coding has been designed to simulate and visualize the fractal growth. (author)

  3. Functional Conducting Polymers via Thiol-ene Chemistry

    OpenAIRE

    Martin, David C.; Feldman, Kathleen E.

    2012-01-01

    We demonstrate here that thiol-ene chemistry can be used to provide side-chain functionalized monomers based on 3,4-propylenedioxythiophene (ProDOT) containing ionic, neutral, hydrophobic, and hydrophilic side chains. All reactions gave high yields and purification could generally be accomplished through precipitation. These monomers were polymerized either chemically or electro-chemically to give soluble materials or conductive films, respectively. This strategy provides for facile tuning of...

  4. Thermal Conductivity of Polymer/Nano-filler Blends

    Science.gov (United States)

    Ghose, Sayata; Watson, Kent A.; Delozier, Donovan M.; Working, Dennis C.; Connell, John W.; Smith, Joseph G.; Sun, Y. P.; Lin, Y.

    2006-01-01

    To improve the thermal conductivity of an ethylene vinyl acetate copolymer, Elvax 260 was compounded with three carbon based nano-fillers. Multiwalled carbon nanotubes (MWCNT), vapor grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. In an attempt to improve compatibility between the Elvax and nanofillers, MWCNTs and EGs were modified through non covalent and covalent attachment of alkyl groups. Ribbons were extruded to form samples in which the nanofillers were aligned, and samples were also fabricated by compression molding in which the nano-fillers were randomly oriented. The thermal properties were evaluated by DSC and TGA, and mechanical properties of the aligned samples were determined by tensile testing. The degree of dispersion and alignment of the nanoparticles were investigated using high-resolution scanning electron microscopy. Thermal conductivity measurements were performed using a Nanoflash technique. The thermal conductivity of the samples was measured in both the direction of alignment as well as perpendicular to that direction. The results of this study will be presented.

  5. Process for depositing strong adherend polymer coating onto an electrically conductive surface

    OpenAIRE

    Bertrand, Olivier; Jérôme, Robert; Gautier, Sandrine; Maquet, Véronique; Detrembleur, Christophe; Jérôme, Christine; Voccia, Samuel; Claes, Michaël; Lou, Xudong; Labaye, David-Emmanuel

    2002-01-01

    Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising an electrochemical grafting at the surface of an active monomer for forming a primer coating P onto said surface and having as general formula: X0 (meth)acrylate wherein X is either part of a preformed polymer or is an intermediate agent for polyaddition reaction or is an anchoring group for attachment of a molecule having at least one complementary reactive group. Su...

  6. High Yield Sample Preconcentration Using a Highly Ion-conductive Charge-selective Polymer

    OpenAIRE

    Chun, Honggu; Chung, Taek Dong; Ramsey, J. Michael

    2010-01-01

    The development and analysis of a microfluidic sample preconcentration system using a highly ion-conductive charge-selective polymer (poly-AMPS) is reported. The preconcentration is based on the phenomenon of concentration polarization which develops at the boundaries of the poly-AMPS with buffer solutions. A negatively charged polymer, poly-AMPS, positioned between two microchannels efficiently extracts cations through its large cross section, resulting in efficient anion sample preconcentra...

  7. Rate dependence of electrical and mechanical properties of conductive polymer nanocomposites

    Science.gov (United States)

    Foley, J. R.; Stilson, C. L.; Smith, K. K. G.; McKinion, C. M.; Chen, C.; Ganguli, S.; Roy, A. K.

    2015-09-01

    Conductive polymer nanocomposites with enhanced electrical and thermal properties show promise as an alternative solution for electronic materials. For example, electronic interconnect materials will have comparable electrical and thermal conductivity to solder with an increased operating range of strain and temperature. This paper documents the fabrication and experimental evaluation of a prototype conductive polymer nanocomposite. Material selection, fabrication processes, and initial characterization of a low Tg polymer with a high fill ratio of carbon nanotubes is presented. The electrical and thermal properties of the composite are measured and compared with predictions. The mechanical properties are measured using dynamic mechanical analysis (DMA) over a wide temperature range. The mechanical and electrical responses of the conductive polymer composite are simultaneously measured at higher strain rates using a modified split Hopkinson pressure bar (SHPB) apparatus. The dynamic stress-strain response is obtained using traditional analytic methods (e.g., two- and three-wave analysis). The electrical response is observed using constant current excitation with high bandwidth (>500 kHz) instrumentation. The dynamic compression data implies the change in electrical resistance is solely a function of the material deformation, i.e., the material exhibits constant electrical conductivity and is insensitive to the applied loads. DMA and SHPB dynamic data are used to estimate the parameters in a Mulliken-Boyce constitutive model, and the resulting behavior is critically evaluated. Finally, progress towards improving the polymer composite's mechanical, electrical, and thermal properties are discussed.

  8. Destruction and recovery of a nanorod conductive network in polymer nanocomposites via molecular dynamics simulation.

    Science.gov (United States)

    Gao, Yangyang; Cao, Dapeng; Wu, Youping; Liu, Jun; Zhang, Liqun

    2016-03-28

    By adopting coarse-grained molecular dynamics simulation, we investigate the effects of end-functionalization and shear flow on the destruction and recovery of a nanorod conductive network in a functionalized polymer matrix. We find that the end-functionalization of polymeric chains can enhance the electrical conductivity of nanorod filled polymer nanocomposites, indicated by the decrease of the percolation threshold. However, there exists an optimal end-functionalization extent to reach the maximum electrical conductivity. In the case of steady shear flow, both homogeneous conductive probability and directional conductive probability perpendicular to the shear direction decrease with the shear rate, while the directional conductive probability parallel to the shear direction increases. Importantly, we develop a semi-empirical equation to describe the change of the homogeneous conductive probability as a function of the shear rate. Meanwhile, we obtain an empirical formula describing the relationship between the anisotropy of the conductive probability and the orientation of the nanorods. In addition, the conductivity stability increases with increasing nanorod volume fraction. During the recovery process of the nanorod conductive network, it can be fitted well by the model combining classical percolation theory and a time-dependent nanorod aggregation kinetic equation. The fitted recovery rate is similar for different nanorod volume fractions. In summary, this work provides some rational rules for fabricating polymer nanocomposites with excellent performance of electrical conductivity.

  9. How to Control Component Ratio of Conducting Polymer Blend for Organic Photovoltaic Devices by Annealing

    Directory of Open Access Journals (Sweden)

    Bobins Augustine

    2015-01-01

    Full Text Available There are various conducting polymer blends which are used as hole transporting layers (HTL in organic photovoltaic devices (OPV. The electrical performance of these conducting polymer blends depends crucially on its surface compositions and morphology. In this paper, we studied poly(3,4-ethylenedioxythiophene-poly(styrenesulfonate or PEDOT:PSS as an example of the HTL conducting polymer blends used in OPV. We have investigated the effect of annealing PEDOT:PSS in different atmospheres such as vacuum, N2, and air at different temperatures. It was found that the component ratio of the polymer blend is changing with annealing temperature and atmosphere. PSS/PEDOT ratio was found to have clear influence on the electrical performance of the material. In practice, we found that annealing can be used as a method to control component ratio of the HTL conducting polymer blend to achieve better electrical performance in OPV devices. The component ratio changes of the polymer with annealing were understood by X-ray photoelectron spectroscopy (XPS. Annealing in N2 atmosphere at 220°C for 1 hour gave best electrical performance for the polymer and the PSS/PEDOT ratio at that condition was close to 1.1, while the initial ratio was 2.5. Optimizing HTL layer by simple conductivity measurement does not guarantee best performance in OPV since surface property changes during annealing might affect the deposition of successive active layers on top and thus final device. Thus we have optimized annealing condition of the HTL layer according to the OPV performance itself.

  10. Ionic Conductivity and Dielectric Properties of the PAN-Ion Conducting Polymers

    Institute of Scientific and Technical Information of China (English)

    N.M.Ali; L.Othman; K.B.Md; Isa; A.Ahmad; Z.Osman

    2007-01-01

    1 Results In this work, the ion conducting films of polyacrylonitrile (PAN) containing lithium triflate (LiCF3SO3) and sodium triflate (NaCF3SO3) were prepared by the solution casting technique. The ionic conductivity measurements were carried out using impedance spectroscopy. The room temperature conductivity for pure polyacrylonitrile film is 1.51×10-11 S·cm-1. The room temperature conductivity for the highest conducting film in the PAN-LiCF3SO3 and PAN-NaCF3SO3 systems is 1.51×10-5 and 7.99×10-6 S·...

  11. Morphology and Electrical Conductivity of Carbon Nanocoatings Prepared from Pyrolysed Polymers

    OpenAIRE

    Marcin Molenda; Michał Świętosławski; Marek Drozdek; Barbara Dudek; Roman Dziembaj

    2014-01-01

    Conductive carbon nanocoatings (conductive carbon layers—CCL) were formed on α-Al2O3 model support using three different polymer precursors and deposition methods. This was done in an effort to improve electrical conductivity of the material through creating the appropriate morphology of the carbon layers. The best electrical properties were obtained with use of a precursor that consisted of poly-N-vinylformamide modified with pyromellitic acid (PMA). We demonstrate that these properties orig...

  12. Electrooptical characteristics of the novelty system: ionic doped liquid crystal - conductive polymer

    OpenAIRE

    Mykytyuk, T.; Aksimentyeva, O.; Stakhira, P.; Cherpak, V.; Fechan, A.; Konopelnik, O.; Fomenko, V.; Hlushyk, I.

    2004-01-01

    Taking into account that ionic-doped liquid crystals are conductive and the conductance depends on dopant concentration, we suggested using ionic-doped liquid crystals as a electrolytic medium in a described configuration of cell. The application of an ionic doped liquid crystal as electrolytic medium in electrochromic device were investigated. Polyaniline is a conductive polymer and has electrochromic effect in an electrolytic medium under the applied voltage. The spectral investigation of t...

  13. Modification of Conductive Polymer for Polymeric Anodes of Flexible Organic Light-Emitting Diodes

    OpenAIRE

    Wang Guang-Feng; Tao Xiao-Ming; Xin John; Fei Bin

    2009-01-01

    Abstract A conductive polymer, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), was modified with dimethyl sulfoxide (DMSO) in solution state, together with sub-sequential thermal treatment of its spin-coated film. The electrical conductivity increased by more than three orders of magnitude improvement was achieved. The mechanism for the conductivity improvement was studied at nanoscale by particle size analysis, field emission scanning electron microscopy (FESEM), and X-...

  14. Novel conducting polymer based composite coatings for corrosion protection of zinc

    International Nuclear Information System (INIS)

    Highlights: • The introduction of carbon black has solved the problem of Fermi-level misalignment. • Carbon black supplies conductive pathways to activate more amount of PEDOT. • The active charge of PEDOT is investigated by Scanning Kelvin Probe. • Corrosion protection is achieved by the coating with the optimal concentration of carbon black. • The delamination inhibition is due to the active polarization of the interface. - Abstract: The application of conducting polymers on zinc tends to result in an electronically highly insulating interface leading even to Fermi-level misalignment at the polymer/metal interface. This makes the conducting polymers electrochemically inactive. To prevent this Fermi-level misalignment, carbon black was introduced as conductive spacer between the conducting polymer and the zinc into composite coatings of poly (3,4-ethylenedioxythiophene) (PEDOT) nanoparticles and a polyvinyl butyral (PVB) binder. It was found that the carbon black not only enabled electronic contact between zinc and the PEDOT, but also increased the amount of electrochemical available PEDOT in the coating, by supplying the necessary conductive pathways

  15. Ion beam irradiation as a tool to improve the ionic conductivity in solid polymer electrolyte systems

    Science.gov (United States)

    Manjunatha, H.; Damle, R.; Kumaraswamy, G. N.

    2016-05-01

    Solid polymer electrolytes (SPEs) have potential applications in solid state electronic and energy devices. The optimum conductivity of SPEs required for such applications is about 10-1 - 10-3 Scm-1, which is hard to achieve in these systems. It is observed that ionic conductivity of SPEs continuously increase with increasing concentration of inorganic salt in the host polymer. However, there is a critical concentration of the salt beyond which the conductivity of SPEs decreases due to the formation of ion pairs. In the present study, solid polymer thin films based on poly (ethylene oxide) (PEO) complexed with NaBr salt with different concentrations have been prepared and the concentration at which ion pair formation occurs in PEOxNaBr is identified. The microstructure of the SPE with highest ionic conductivity is modified by irradiating it with low energy O+1 ion (100 keV) of different fluencies. It is observed that the ionic conductivity of irradiated SPEs increases by one order in magnitude. The increase in ionic conductivity may be attributed to the enhanced segmental motion of the polymer chains due to radiation induced micro structural modification.

  16. Thermoelectric Behavior of Conducting Polymers Hybridized with Inorganic Nanoparticles

    Science.gov (United States)

    Son, Woohyun; Lee, Seung Hwan; Park, Hongkwan; Choi, Hyang Hee; Kim, Jung Hyun

    2016-06-01

    We introduce a simple and facile method for fabrication of a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/germanium nanoparticle (Ge NP) composite film with enhanced thermoelectric conversion efficiency. The Ge NP were prepared by mechanical grinding and mixed with solution-phase PEDOT:PSS. The film processability of the composite was excellent and the overall process did not involve complicated synthetic procedures. The thermoelectric power factor of the composite film was optimized to 31.20 μW m-1 K-2 by controlling the composition. The composite film had an exceptionally low thermal conductivity of 0.417 W m-1 K-1 and the thermoelectric figure of merit ( ZT) was maximized at 0.0223 at room temperature. The mechanism for the improvement of the thermoelectric conversion efficiency was investigated by introducing energy models based on interfacial scattering of charge carriers and phonons. We expect that this robust method could lead to a facile route for design of organic-inorganic composite-based thermoelectric materials.

  17. Chemical mechanical polishing of transparent conductive layers using spherical cationic polymer microbeads

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, Shoji, E-mail: nagaoka@kmt-iri.go.jp [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Ryu, Naoya [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Yamanouchi, Akio [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Shirosaki, Tomohiro [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Horikawa, Maki [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Sakurai, Hideo; Takafuji, Makoto; Ihara, Hirotaka [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan)

    2015-02-02

    Spherical cationic polymer microbeads were used to chemically mechanically polish transparent conductive oxide (TCO) layers without the need for inorganic abrasives. Poly(methyl acrylate) (PMA) was used as the polymer matrix. Surface cationization of the spherical PMA microbeads was achieved by aminolysis using 1,2-diaminoethane. The amino group content of the microbeads was controlled using the aminolysis reaction time. The surface roughness of the TCO polished using the cationic polymer microbeads was similar to that of TCO polished with an inorganic abrasive. The microbead-polished TCO layer was slightly thinner than the unpolished TCO layer. The sheet resistance of the TCO layer polished using the microbeads was lower than that polished using the inorganic abrasive. The TCO polishing ability of the microbeads was dependent on their cationic properties and softness. - Highlights: • Indium tin oxide (ITO) layer was planarized using cationic polymer microbeads. • Cationic polymer microbeads planarized, while retaining ITO layer thickness • Cationic polymer microbeads did not degrade the sheet resistance of ITO. • Cationic polymer microbeads could planarize the ITO surface without damaging.

  18. Chemical mechanical polishing of transparent conductive layers using spherical cationic polymer microbeads

    International Nuclear Information System (INIS)

    Spherical cationic polymer microbeads were used to chemically mechanically polish transparent conductive oxide (TCO) layers without the need for inorganic abrasives. Poly(methyl acrylate) (PMA) was used as the polymer matrix. Surface cationization of the spherical PMA microbeads was achieved by aminolysis using 1,2-diaminoethane. The amino group content of the microbeads was controlled using the aminolysis reaction time. The surface roughness of the TCO polished using the cationic polymer microbeads was similar to that of TCO polished with an inorganic abrasive. The microbead-polished TCO layer was slightly thinner than the unpolished TCO layer. The sheet resistance of the TCO layer polished using the microbeads was lower than that polished using the inorganic abrasive. The TCO polishing ability of the microbeads was dependent on their cationic properties and softness. - Highlights: • Indium tin oxide (ITO) layer was planarized using cationic polymer microbeads. • Cationic polymer microbeads planarized, while retaining ITO layer thickness • Cationic polymer microbeads did not degrade the sheet resistance of ITO. • Cationic polymer microbeads could planarize the ITO surface without damaging

  19. Study of Swift Heavy Ion Modified Conducting Polymer Composites for Application as Gas Sensor

    Directory of Open Access Journals (Sweden)

    Ulrich W. Scherer

    2006-04-01

    Full Text Available A polyaniline-based conducting composite was prepared by oxidativepolymerisation of aniline in a polyvinylchloride (PVC matrix. The coherent free standingthin films of the composite were prepared by a solution casting method. The polyvinylchloride-polyaniline composites exposed to 120 MeV ions of silicon with total ion fluenceranging from 1011 to 1013 ions/cm2, were observed to be more sensitive towards ammoniagas than the unirradiated composite. The response time of the irradiated composites wasobserved to be comparably shorter. We report for the first time the application of swiftheavy ion modified insulating polymer conducting polymer (IPCP composites for sensingof ammonia gas.

  20. Thermal Conductivity of 3D CNT-Polymer Composites with Controlled Dispersion

    Science.gov (United States)

    Klittich, Mena; Wang, Xue; Dhinojwala, Ali

    The high thermal conductivity of isolated carbon nanotubes (CNTs) has inspired its use as a thermal filler for insulative polymers. However, the performance of these composites has consistently been sub par. Extensive analyses of these complex systems have resulted in the conclusion that resistance at the CNT/polymer interface due to phonon mismatch and poor physical binding, as well as the weakly bonded tube-tube interactions restrict the effectiveness of CNTs in practice. Experimental comparisons of CNT treatments, coatings, functionalization, and interactions with various polymers have proved challenging, due to the interconnected nature of the composite properties. Here, we have reversed the paradigm and used a constant CNT structure that is then modified post-growth to allow for direct comparisons of polymer composites.

  1. Electrochemomechanical Behaviour of Bilayer and Trilayer Films with PEDOT and PPY Conducting Polymers

    DEFF Research Database (Denmark)

    Zainudeen, Umer L.; Careem, M.A.; Skaarup, Steen

    2008-01-01

    A detailed study on bilayer and trilayer films prepared with polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymers is reported. Both polymers are doped with dodecyl benzenesulfonate (DBS) anions. These multi layer films were prepared electrochemically so that the PEDOT...... individual polymer. In trilayer films, the reduction of inner and outer PPy layers takes place at two different potentials. The oxidation occurs at one potential only. The separation between the two reduction peaks depends on the thickness of PEDOT layer, the scan rate and the concentration of cycling...... electrolyte. This separation becomes smaller with the number of cycles, indicating the enhancement of ion diffusion through the PEDOT layer. Electrochemomechanical measurements show that the strain generated in the polymer significantly decreases with increasing scan rate. Rapid increment in strain...

  2. Highly conductive polymer electrolyte membranes modified with polyethylene glycol-bis-carbamate

    Science.gov (United States)

    Fu, Guopeng; Dempsey, Janel; Kyu, Thein

    By virtue of its non-flammability and chemical stability, polyethylene glycol (PEG) networks have shown potential application in all solid-state polymer electrolyte membranes (PEM). However, room temperature ionic conductivity of these PEG based PEMs is inherently low. Plasticization of these PEMs is needed to improve the ionic conductivity. It was demonstrated by this group that small-molecule plasticizers such as succinonitrile, ethylene carbonate, or urea-carbamate can boost ionic conductivity of solid-state polymer electrolyte membranes. Polyethylene glycol bis-carbamate (PEGBC) was synthesized via condensation reaction of polyethylene glycol diamine and ethylene carbonate. The PEGBC modified PEM has shown higher ionic conductivity relative to the unmodified PEM. Moreover, PEGBC modified PEM has a better thermal stability relative to ethylene carbonate based liquid electrolyte with enhanced ionic conductivity. Supported by NSF-DMR 1161070, 1502543 and REU 1359321.

  3. Layered conductive polymer on nylon membrane templates for high performance, thin-film supercapacitor electrodes

    Science.gov (United States)

    Shi, HaoTian Harvey; Naguib, Hani E.

    2016-04-01

    Flexible Thin-film Electrochemical Capacitors (ECs) are emerging technology that plays an important role as energy supply for various electronics system for both present era and the future. Intrinsically conductive polymers (ICPs) are promising pseudo-capacitive materials as they feature both good electrical conductivity and high specific capacitance. This study focuses on the construction and characterization of ultra-high surface area porous electrodes based on coating of nano-sized conductive polymer materials on nylon membrane templates. Herein, a novel nano-engineered electrode material based on nylon membranes was presented, which allows the creation of super-capacitor devices that is capable of delivering competitive performance, while maintaining desirable mechanical characteristics. With the formation of a highly conductive network with the polyaniline nano-layer, the electrical conductivity was also increased dramatically to facilitate the charge transfer process. Cyclic voltammetry and specific capacitance results showed promising application of this type of composite materials for future smart textile applications.

  4. Observation of irreversible current path in polymer dielectric using conductive atomic force microscope

    Science.gov (United States)

    Jung, Ji-Hoon; Kim, Woo Young; Kim, Do-Kyung; Kwon, Jin-Hyuk; Lee, Hee Chul; Bae, Jin-Hyuk

    2015-03-01

    During the measurement of the electrical properties of a metal-polymer-metal capacitor, it was found that the capacitor exhibited write-once-read-many-times (WORM) memory behavior, even though it was made of the dielectric polymer, polystyrene. The initial low conductance state changed to a high conductance state when a threshold voltage was applied, but this final state never reverted to the initial state. This phenomenon only appeared in sub-100-nm-thick films. To understand this phenomenon, conductive atomic force microscopy (CAFM) was used. The current distribution measured with CAFM showed an irreversible current path had formed near particles in the polymer film. For reproducibility, particles were intentionally inserted into the polymer film during the fabrication of metal-polymer-metal capacitors, and the same current mechanism was found. From these results, it is concluded that the purification and cleaning process of organic devices severely affects the device characteristics. In addition, particle-insertion appears to be a promising method for fabrication low-cost and air-stable WORM type memory for various applications. [Figure not available: see fulltext.

  5. Ti3C2Tx Filler Effect on the Proton Conduction Property of Polymer Electrolyte Membrane.

    Science.gov (United States)

    Liu, Yahua; Zhang, Jiakui; Zhang, Xiang; Li, Yifan; Wang, Jingtao

    2016-08-10

    Conductive polymer electrolyte membranes are increasingly attractive for a wide range of applications in hydrogen-relevant devices, for instance hydrogen fuel cells. In this study, two-dimensional Ti3C2Tx, a typical representative of the recently developed MXene family, is synthesized and employed as a universal filler for its features of large specific surface area, high aspect ratio, and sufficient terminated -OH groups. The Ti3C2Tx is incorporated into polymer matrix to explore its function on membrane microstructure and proton conduction property. Both phase-separated (acidic Nafion and sulfonated poly(ether ether ketone)) and non-phase-separated (basic chitosan) polymers are utilized as membrane matrixes. The microstructures, physicochemical properties, and proton conduction properties of the membranes are extensively investigated. It is demonstrated that Ti3C2Tx generates significant promotion effect on proton conduction of the composite membrane by facilitating both vehicle-type and Grotthuss-type proton transfer, yielding several times increased proton conductivity for every polymer-based composite membrane under various conditions, and the composite membrane achieves elevated hydrogen fuel cell performance. The stable Ti3C2Tx also reinforces the thermal and mechanical stabilities of these composite membranes. Since the MXene family includes more than 70 members, this exploration is expected to open up new perspectives for expanding their applications, especially as membrane modifiers and proton conductors. PMID:27430190

  6. Microfabrication of a Polymer Based Bi-Conductive Membrane for a Polymer Electrolyte Membrane Fuel Cell

    International Nuclear Information System (INIS)

    This paper reports a novel fabrication process of a high active area ratio bi-conductive membrane for PEMFCs. The fabricated device is a 50μm thick flexible polyimide based membrane that integrates for the first time lateral electrical conductive layers on both sides with a through ionic conductive path. With the use of thermo-conductive rubber as a bonding agent allowing a quick-flip process, five configurations of double-sided multilayer metal sputtering on polyimide were tested. An approach for filling through pores in the membrane with the ionic conductor (Nafion) with a temporary reservoir was also developed. The development of these new processes allowed to fabricate a membrane with 50μm wide holes filled with ionic conductor with double-sided electrical conductive layers

  7. Controlled Aloin Release from Crosslinked Polyacrylamide Hydrogels: Effects of Mesh Size, Electric Field Strength and a Conductive Polymer

    OpenAIRE

    Anuvat Sirivat; Amornrat Niansiri; Sumonman Niamlang; Tawansorn Buranut

    2013-01-01

    The aim of this paper is to investigate the effects of hydrogel mesh size, a conductive polymer, and electric field strength on controlled drug delivery phenomena using drug-loaded polyacrylamide hydrogels prepared at various crosslinking ratios both with and without a conductive polymer system. Poly(p-phenylene vinylene), PPV, as the model conductive polymer, was used to study its ability to control aloin released from aloin-doped poly(p-phenylene vinylene)/polyacrylamide hydrogel (aloin-dop...

  8. Developments in the Field of Conducting and Non-conducting Polymer Based Potentiometric Membrane Sensors for Ions Over the Past Decade

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Ganjali

    2008-04-01

    Full Text Available Many research studies have been conducted on the use of conjugated polymers in the construction of chemical sensors including potentiometric, conductometric and amperometric sensors or biosensors over the last decade. The induction of conductivity on conjugated polymers by treating them with suitable oxidizing agents won Heeger, MacDiarmid and Shirakawa the 2000 Nobel Prize in Chemistry. Common conjugated polymers are poly(acetylenes, poly(pyrroles, poly(thiophenes, poly(terthiophenes, poly(anilines, poly(fluorines, poly(3-alkylthiophenes, polytetrathiafulvalenes, polynapthalenes, poly(p-phenylene sulfide, poly(p-phenylenevinylenes, poly(3,4-ethylenedioxythiophene, polyparaphenylene, polyazulene, polyparaphenylene sulfide, polycarbazole and polydiaminonaphthalene. More than 60 sensors for inorganic cations and anions with different characteristics based on conducting polymers have been reported. There have also been reports on the application of non-conducting polymers (nCPs, i.e. PVC, in the construction of potentiometric membrane sensors for determination of more than 60 inorganic cations and anions. However, the leakage of ionophores from the membranes based on these polymers leads to relatively lower life times. In this article, we try to give an overview of Solid-Contact ISE (SCISE, Single-Piece ISE (SPISE, Conducting Polymer (CP-Based, and also non-conducting polymer PVC-based ISEs for various ions which their difference is in the way of the polymer used with selective membrane. In SCISEs and SPISEs, the plasticized PVC containing the ionophore and ionic additives govern the selectivity behavior of the electrode and the conducting polymer is responsible of ion-to-electron transducer. However, in CPISEs, the conducting polymer layer is doped with a suitable ionophore which enhances the ion selectivity of the CP while its redox response has to be suppressed.

  9. Sulfonation and characterization of styrene-indene copolymers for the development of proton conducting polymer membranes

    Directory of Open Access Journals (Sweden)

    Cristiane M. Becker

    2012-01-01

    Full Text Available The aim of this work is to obtain polymer precursors based on styrene copolymers with distinct degrees of sulfonation, as an alternative material for fuel cell membranes. Acetyl sulfate was used to carry out the sulfonation and the performance of the polyelectrolyte was evaluated based on the content of acid polar groups incorporated into the macromolecular chain. Polymeric films were produced by blending the sulfonated styrene-indene copolymer with poly(vinylidene fluoride. The degree of sulfonation of the polymer was strongly affected by the sulfonation reaction parameters, with a direct impact on the ionic exchange capacity and the ionic conductivity of the sulfonated polymers and the membranes obtained from them. The films produced with the blends showed more suitable mechanical properties, although the conductivity of the membranes was still lower than that of commercially available membranes used in fuel cells.

  10. Conducting polymer and its composite materials based electrochemical sensor for Nicotinamide Adenine Dinucleotide (NADH).

    Science.gov (United States)

    Omar, Fatin Saiha; Duraisamy, Navaneethan; Ramesh, K; Ramesh, S

    2016-05-15

    Nicotinamide Adenine Dinucleotide (NADH) is an important coenzyme in the human body that participates in many metabolic reactions. The impact of abnormal concentrations of NADH significantly causes different diseases in human body. Electrochemical detection of NADH using bare electrode is a challenging task especially in the presence of main electroactive interferences such as ascorbic acid (AA), uric acid (UA) and dopamine (DA). Modified electrodes have been widely explored to overcome the problems of poor sensitivity and selectivity occurred from bare electrodes. This review gives an overview on the progress of using conducting polymers, polyelectrolyte and its composites (co-polymer, carbonaceous, metal, metal oxide and clay) based modified electrodes for the sensing of NADH. In addition, developments on the fabrication of numerous conducting polymer composites based modified electrodes are clearly described. PMID:26774092

  11. Fast prototyping of conducting polymer microelectrodes using resistance-controlled high precision drilling

    DEFF Research Database (Denmark)

    Kafka, Jan Robert; Geschke, Oliver; Skaarup, Steen;

    2011-01-01

    We present a straightforward method for fast prototyping of microelectrode arrays in the highly conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT). Microelectrode arrays were produced by electrical resistance-controlled microdrilling through an insulating polymer layer (TOPAS® 5013...... of 130μm and 300μm, respectively, were fabricated. Their functionality was verified by chronoamperometry on potassium ferro-/ferricyanide. Comparison of the experimentally obtained results to finite element modeling of the respective electrode configurations shows that the conducting polymer electrodes...... approach the steady state currents predicted from modeling, but at a much slower rate than expected. This is shown to be caused by the use of electroactive PEDOT electrodes. Subtraction of the latter contribution gives approach to steady state currents within a few seconds, which is in very good agreement...

  12. Hierarchical patterning of multifunctional conducting polymer nanoparticles as a bionic platform for topographic contact guidance.

    Science.gov (United States)

    Ho, Dominic; Zou, Jianli; Chen, Xianjue; Munshi, Alaa; Smith, Nicole M; Agarwal, Vipul; Hodgetts, Stuart I; Plant, Giles W; Bakker, Anthony J; Harvey, Alan R; Luzinov, Igor; Iyer, K Swaminathan

    2015-02-24

    The use of programmed electrical signals to influence biological events has been a widely accepted clinical methodology for neurostimulation. An optimal biocompatible platform for neural activation efficiently transfers electrical signals across the electrode-cell interface and also incorporates large-area neural guidance conduits. Inherently conducting polymers (ICPs) have emerged as frontrunners as soft biocompatible alternatives to traditionally used metal electrodes, which are highly invasive and elicit tissue damage over long-term implantation. However, fabrication techniques for the ICPs suffer a major bottleneck, which limits their usability and medical translation. Herein, we report that these limitations can be overcome using colloidal chemistry to fabricate multimodal conducting polymer nanoparticles. Furthermore, we demonstrate that these polymer nanoparticles can be precisely assembled into large-area linear conduits using surface chemistry. Finally, we validate that this platform can act as guidance conduits for neurostimulation, whereby the presence of electrical current induces remarkable dendritic axonal sprouting of cells.

  13. Semi-metallic, strong conductive polymer microfiber, method and fast response rate actuators and heating textiles

    KAUST Repository

    Zhou, Jian

    2016-06-09

    A method comprising: providing at least one first composition comprising at least one conjugated polymer and at least one solvent, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one fiber to form at least one second fiber material. In lead embodiments, high-performance poly(3,4-ethylenedioxy- thiophene)/poly(styrenesulfonate) (PEDOT/PSS) conjugated polymer microfibers were fabricated via wet- spinning followed by hot-drawing. In these lead embodiments, due to the combined effects of the vertical hot-drawing process and doping/de-doping the microfibers with ethylene glycol (EG), a record electrical conductivity of 2804 S · cm-1 was achieved. This is believed to be a six-fold improvement over the best previously reported value for PEDOT/PSS fibers (467 S · cm-1) and a twofold improvement over the best values for conductive polymer films treated by EG de-doping (1418 S · cm-1). Moreover, these lead, highly conductive fibers experience a semiconductor-metal transition at 313 K. They also have superior mechanical properties with a Young\\'s modulus up to 8.3 GPa, a tensile strength reaching 409.8 MPa and a large elongation before failure (21%). The most conductive fiber also demonstrates an extraordinary electrical performance during stretching/unstretching: the conductivity increased by 25% before the fiber rupture point with a maximum strain up to 21%. Simple fabrication of the semi-metallic, strong and stretchable wet-spun PEDOT/PSS microfibers can make them available for conductive smart electronics. A dramatic improvement in electrical conductivity is needed to make conductive polymer fibers viable candidates in applications such as flexible electrodes, conductive textiles, and fast-response sensors and actuators.

  14. Thermal conductivity of polymer composites with the geometrical characteristics of graphene nanoplatelets.

    Science.gov (United States)

    Kim, Hyun Su; Bae, Hyun Sung; Yu, Jaesang; Kim, Seong Yun

    2016-05-25

    One of the most important physical factors related to the thermal conductivity of composites filled with graphene nanoplatelets (GNPs) is the dimensions of the GNPs, that is, their lateral size and thickness. In this study, we reveal the relationship between the thermal conductivity of polymer composites and the realistic size of GNP fillers within the polymer composites (measured using three-dimensional (3D) non-destructive micro X-ray CT analysis) while minimizing the effects of the physical parameters other than size. A larger lateral size and thickness of the GNPs increased the likelihood of the matrix-bonded interface being reduced, resulting in an effective improvement in the thermal conductivity and in the heat dissipation ability of the composites. The thermal conductivity was improved by up to 121% according to the filler size; the highest bulk and in-plane thermal conductivity values of the composites filled with 20 wt% GNPs were 1.8 and 7.3 W/m·K, respectively. The bulk and in-plane thermal conductivity values increased by 650 and 2,942%, respectively, when compared to the thermal conductivity values of the polymer matrix employed (0.24 W/m·K).

  15. Thermal conductivity of polymer composites with the geometrical characteristics of graphene nanoplatelets

    Science.gov (United States)

    Kim, Hyun Su; Bae, Hyun Sung; Yu, Jaesang; Kim, Seong Yun

    2016-01-01

    One of the most important physical factors related to the thermal conductivity of composites filled with graphene nanoplatelets (GNPs) is the dimensions of the GNPs, that is, their lateral size and thickness. In this study, we reveal the relationship between the thermal conductivity of polymer composites and the realistic size of GNP fillers within the polymer composites (measured using three-dimensional (3D) non-destructive micro X-ray CT analysis) while minimizing the effects of the physical parameters other than size. A larger lateral size and thickness of the GNPs increased the likelihood of the matrix-bonded interface being reduced, resulting in an effective improvement in the thermal conductivity and in the heat dissipation ability of the composites. The thermal conductivity was improved by up to 121% according to the filler size; the highest bulk and in-plane thermal conductivity values of the composites filled with 20 wt% GNPs were 1.8 and 7.3 W/m·K, respectively. The bulk and in-plane thermal conductivity values increased by 650 and 2,942%, respectively, when compared to the thermal conductivity values of the polymer matrix employed (0.24 W/m·K). PMID:27220415

  16. Electrical Conductivity and Current-Voltage Characteristics of Individual Conducting Polymer PEDOT Nanowires

    Institute of Scientific and Technical Information of China (English)

    LONG Yun-Ze; DUVAIL Jean-Luc; CHEN Zhao-Jia; JIN Ai-Zi; GU Chang-Zhi

    2008-01-01

    We report the current-voltage (I-V) characteristics and electrical conductivity of individual template-synthesized poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires (190 ± 6 nm in diameter and σRT : 11.2±2Ω-1cm-1)over a wide temperature range from 300 to 10K. With lowering temperature, the Ⅰ- Ⅴ characteristics become nonlinear around 50 K, and a clear Coulomb gap-like structure appears in the differential conductance (dI/dV)spectra. The temperature dependence of the resistance below 70 K follows ln R ∝ T-1/2, which can be interpreted as Efros-Shklovskii hopping conduction in the presence of a Coulomb gap. In addition, the influences of measurement methods such as the applied bias voltage magnitude, the two-probe and four-probe techniques used in the resistance measurements are also reported and discussed.

  17. Hybrid solar cells with conducting polymers and vertically aligned silicon nanowire arrays: The effect of silicon conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Sungho, E-mail: shwoo@dgist.ac.kr [Green Energy Research Division, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of); Hoon Jeong, Jae [Green Energy Research Division, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of); Organic Nanoelectronics Laboratory, Department of Chemical Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kun Lyu, Hong; Jeong, Seonju; Hyoung Sim, Jun; Hyun Kim, Wook [Green Energy Research Division, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of); Soo Han, Yoon [Department of Advanced Energy Material Science and Engineering, Catholic University of Daegu, Gyeongbuk 712-702 (Korea, Republic of); Kim, Youngkyoo, E-mail: ykimm@knu.ac.kr [Organic Nanoelectronics Laboratory, Department of Chemical Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2012-08-01

    Organic/inorganic hybrid solar cells, based on vertically aligned n-type silicon nanowires (n-Si NWs) and p-type conducting polymers (PEDOT:PSS), were investigated as a function of Si conductivity. The n-Si NWs were easily prepared from the n-Si wafer by employing a silver nanodot-mediated micro-electrochemical redox reaction. This investigation shows that the photocurrent-to-voltage characteristics of the n-Si NW/PEDOT:PSS cells clearly exhibit a stable rectifying diode behavior. The increase in current density and fill factor using high conductive silicon is attributed to an improved charge transport towards the electrodes achieved by lowering the device's series resistance. Our results also show that the surface area of the nanowire that can form heterojunction domains significantly influences the device performance.

  18. Photomodulation spectroscopy of photocarrier dynamics, electronic defects and morphology of conducting polymers

    International Nuclear Information System (INIS)

    A variety of techniques were used: CW photomodulation, photomodulation in femtosecond and picosecond time ranges, CW resonant Raman scattering, transient photoinduced Raman scattering, electro-absorption, degenerate four-wave mixing, spin dependent photomodulation, and absorption detected magnetic resonance. The following conducting polymers were studied: polyacetylene, polythiophene, polydiacetylene 4-BCMU, polydiethynylsilanes, polysilane embedded in a-Si:H matrix, and fullerenes

  19. Meniscus confined fabrication of multidimensional conducting polymer nanostructures with scanning electrochemical cell microscopy (SECCM).

    Science.gov (United States)

    McKelvey, Kim; O'Connell, Michael A; Unwin, Patrick R

    2013-04-14

    Scanning electrochemical cell microscopy (SECCM) is demonstrated as a new approach for the construction of extended multi-dimensional conducting polymer (polyaniline) nanostructures, making use of a mobile dual-channel theta pipette cell to control and monitor the location, rate and extent of electropolymerisation.

  20. Schemes for the use of conducting polymers as active materials in electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Rudge, A.; Davey, J.; Gottesfeld, S. [Los Alamos National Lab., NM (United States); Ferraris, J.P. [Texas Univ., Richardson, TX (United States). Dept. of Chemistry

    1993-05-01

    The development of a novel conducting polymer based system for use in electrochemical capacitors is described. This system utilizes a new conducting polymer, poly-3-(4-fluorophenyl)-thiophene (PFPT), that can be reversibly n- and p-doped to high charge density. The electrochemical n-dopability of this material can be further improved by cycling in acetonitrile solution that contains a new electrolyte, tetramethylammonium trifluoromethanesulfonate (Me{sub 4}NCF{sub 3}SO{sub 3}). We discuss these improvements in n-dopability in terms of potential electronic and steric influences. We believe that the substituent fluorophenyl group does not communicate with the polythiophene backbone through resonance, and conclude that the ability to n-dope PFPT to high charge density may occur as a result of electron transfer reactions from the conducting polymer backbone into the substituent. This new system for electrochemical capacitors provides the best achievable performance from conducting polymers and generates high energy and power densities that are comparable with noble metal oxide systems, potentially at a fraction of the cost.

  1. Schemes for the use of conducting polymers as active materials in electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Rudge, A.; Davey, J.; Gottesfeld, S. (Los Alamos National Lab., NM (United States)); Ferraris, J.P. (Texas Univ., Richardson, TX (United States). Dept. of Chemistry)

    1993-01-01

    The development of a novel conducting polymer based system for use in electrochemical capacitors is described. This system utilizes a new conducting polymer, poly-3-(4-fluorophenyl)-thiophene (PFPT), that can be reversibly n- and p-doped to high charge density. The electrochemical n-dopability of this material can be further improved by cycling in acetonitrile solution that contains a new electrolyte, tetramethylammonium trifluoromethanesulfonate (Me[sub 4]NCF[sub 3]SO[sub 3]). We discuss these improvements in n-dopability in terms of potential electronic and steric influences. We believe that the substituent fluorophenyl group does not communicate with the polythiophene backbone through resonance, and conclude that the ability to n-dope PFPT to high charge density may occur as a result of electron transfer reactions from the conducting polymer backbone into the substituent. This new system for electrochemical capacitors provides the best achievable performance from conducting polymers and generates high energy and power densities that are comparable with noble metal oxide systems, potentially at a fraction of the cost.

  2. Performance Improvement by Layout Designs of Conductive Polymer Microelectrode Based Impedimetric Biosensors

    DEFF Research Database (Denmark)

    Rosati, Giulio; Daprà, Johannes; Cherré, Solène;

    2014-01-01

    In this work we present a theoretical, computational, and experimental evaluation of the performance of an impedimetric biosensor based on interdigitated conductive polymer (PEDOT:TsO) microelectrodes in a microfluidic system. The influence of the geometry of the electrodes and microchannels on t...

  3. Integration of microwave MEMS devices into rectangular waveguide with conductive polymer interposers

    OpenAIRE

    Baghchehsaraei, Zargham; Sterner, Mikael; Åberg, Jan; Oberhammer, Joachim

    2013-01-01

    This paper investigates a novel method of integrating microwave microelectromechanical systems (MEMS) chips into millimeter-wave rectangular waveguides. The fundamental difficulties of merging micromachined with macromachined microwave components, in particular, surface topography, roughness, mechanical stress points and air gaps interrupting the surface currents, are overcome by a double-side adhesive conductive polymer interposer. This interposer provides a uniform electrical contact, stabl...

  4. Carbon nanotubes with silver nanoparticle decoration and conductive polymer coating for improving the electrical conductivity of polycarbonate composites

    KAUST Repository

    Patole, Archana S.

    2015-01-01

    We proposed a strategy to enhance the conductivity of polycarbonate by using three-phase hybrid metallic/non-metallic fillers. Ethylene diamine (EDA) functionalized multiwalled carbon nanotubes (MWCNT-EDA) are first decorated with silver nanoparticles. These Ag/ MWCNT-EDA fillers are then coated with a conductive layer of ethylene glycol treated PEDOT: PSS (poly [3,4-ethylenedioxythiophene]: poly [styrenesulfonate]) (EP). In such an approach, the MWCNT backbone is covered by a highly conductive coating made of Ag nanoparticles surrounded by EP. To understand how Ag and EP form a highly conductive coating, the effect of different wt% of Ag nanoparticles on EP was studied. Ag nanoparticles around the size of 128 ± 28 nmeffectively lowered the volume resistivity of bulk EP, resulting in a highly conducting Ag/EP blend. We found that in the final Ag/MWCNT-EDA/EP assembly, the EP coating enhances the electrical conductivity in two ways: (1) it is an efficient dispersing agent that helps in achieving a uniform dispersion of the Ag/MWCNT-EDA and (2) it acts as a conductive bridge between particles (Ag and MWCNT-EDA), reducing the particle to particle resistivity. When inserted into polycarbonate, this three-phase blend successfully reduced the volume resistivity of the polymer by two orders of magnitude compared with previous approaches.

  5. Tunable architecture for flexible and highly conductive graphene-polymer composites

    OpenAIRE

    Noël, Amélie; Faucheu, Jenny; Rieu, Mathilde; Viricelle, Jean-Paul; Bourgeat-Lami, Elodie

    2014-01-01

    International audience Printed electronics, particularly on flexible and textile substrates, raised a strong interest during the past decades. This work presents a good candidate for conductive inks based on a graphene/polymer nanocomposite material that gathers three main benefits that are 1 - neither clogging nor flocculation, 2 - spontaneous film formation around room temperature, 3 - high conductivity. Nanosized Multilayered Graphene (NMG) is produced through a solvent-free procedure, ...

  6. Electrochemical Synthesis of a Microporous Conductive Polymer Based on a Metal-Organic Framework Thin Film

    KAUST Repository

    Lu, Chunjing

    2014-05-22

    A new approach to preparing 3D microporous conductive polymer has been demonstrated in the electrochemical synthesis of a porous polyaniline network with the utilization of a MOF thin film supported on a conducting substrate. The prepared porous polyaniline with well-defined uniform micropores of 0.84 nm exhibits a high BET surface area of 986 m2 g−1 and a high electric conductivity of 0.125 S cm−1 when doped with I2, which is superior to existing porous conducting materials of porous MOFs, CMPs, and COFs.

  7. Ion transport study in polymer-nanocomposite films by dielectric spectroscopy and conductivity scaling

    International Nuclear Information System (INIS)

    The dielectric and conductivity response of polymer nanocomposite electrolytes (films of PMMA4LiClO4 dispersed with nano-CeO2 powder) have been investigated. The dielectric behavior was analyzed via the dielectric permittivity (ε′) and dissipation factor (tan δ) of the samples. The analysis has shown the presence of space charge polarization at lower frequencies. The real part of ac conductivity spectra of materials obeys the Jonscher power law. Parameters such as dc conductivity, hopping rate, activation energies and the concentration of charge carriers were determined from conductivity data using the Almond West formalism. It is observed that the higher ionic conductivity at higher temperature is due to increased thermally-activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from activation energy of migration conduction and from Summerfield scaling. The ac conductivity results are also well correlated with TEM results

  8. Gamma- and electron dose response of the electrical conductivity of polyaniline based polymer blends

    International Nuclear Information System (INIS)

    Complete text of publication follows. Conducting polymers, also known as 'synthetic metals' have been the subject of widespread investigations over the past decade due to their very promising characteristics. Polyaniline (PANI) holds a special position among conducting polymers in that its most highly conducting doped form can be reached by protonic acid doping or oxidative doping. It was published earlier, that the electrical conductivity of some polyaniline based polymer composites increases to a significant extent when irradiated to gamma, electron or UV radiation. The aim of the present study was to measure the high frequency conductivity of blended films of PANI with poly(vinylchloride), PVC, and chlorinated poly(propylene) irradiated in air to different doses. In order to find the most suitable composition od these composites the mass percentage of PANI within the PPCl and PVC matrix was changed between 5 - 30%. These samples were then gamma irradiated and the induced electrical conductivity was measured in the 1 kHz - 1 MHz frequency range to determine the most sensitive evaluation conditions. After selecting both the most suitable measuring conditions as well as the blend compositions the dose response of the chosen samples was determined in the dose range of 10 - 250 kGy. With respect to potential dosimetry application the effect of electron irradiation, the effect of irradiation temperature and the stability of the irradiated samples have also been investigated

  9. Highly transparent conductive electrode with ultra-low HAZE by grain boundary modification of aqueous solution fabricated alumina-doped zinc oxide nanocrystals

    Directory of Open Access Journals (Sweden)

    Qiong Nian

    2015-06-01

    Full Text Available Commercial production of transparent conducting oxide (TCO polycrystalline films requires high electrical conductivity with minimal degradation in optical transparency. Aqueous solution deposited TCO films would reduce production costs of TCO films but suffer from low electrical mobility, which severely degrades both electrical conductivity and optical transparency in the visible spectrum. Here, we demonstrated that grain boundary modification by ultra-violet laser crystallization (UVLC of solution deposited aluminium-doped zinc oxide (AZO nanocrystals results in high Hall mobility, with a corresponding dramatic improvement in AZO electrical conductance. The AZO films after laser irradiation exhibit electrical mobility up to 18.1 cm2 V−1 s−1 with corresponding electrical resistivity and sheet resistances as low as 1 × 10−3 Ω cm and 75 Ω/sq, respectively. The high mobility also enabled a high transmittance (T of 88%-96% at 550 nm for the UVLC films. In addition, HAZE measurement shows AZO film scattering transmittance as low as 1.8%, which is superior over most other solution deposited transparent electrode alternatives such as silver nanowires. Thus, AZO films produced by the UVLC technique have a combined figure of merit for electrical conductivity, optical transparency, and optical HAZE higher than other solution based deposition techniques and comparable to vacuumed based deposition methods.

  10. Highly transparent conductive electrode with ultra-low HAZE by grain boundary modification of aqueous solution fabricated alumina-doped zinc oxide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Nian, Qiong; Cheng, Gary J. [Birck Nanotechnology Center and School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Callahan, Michael; Bailey, John [Greentech Solutions, Inc., Hanson, Massachusetts 02341 (United States); Look, David [Semiconductor Research Center, Wright State University, Dayton, Ohio 45435 (United States); Efstathiadis, Harry [College of Nanoscale Science and Engineering (CNSE), University of Albany, Albany, New York 12203 (United States)

    2015-06-01

    Commercial production of transparent conducting oxide (TCO) polycrystalline films requires high electrical conductivity with minimal degradation in optical transparency. Aqueous solution deposited TCO films would reduce production costs of TCO films but suffer from low electrical mobility, which severely degrades both electrical conductivity and optical transparency in the visible spectrum. Here, we demonstrated that grain boundary modification by ultra-violet laser crystallization (UVLC) of solution deposited aluminium-doped zinc oxide (AZO) nanocrystals results in high Hall mobility, with a corresponding dramatic improvement in AZO electrical conductance. The AZO films after laser irradiation exhibit electrical mobility up to 18.1 cm{sup 2} V{sup −1} s{sup −1} with corresponding electrical resistivity and sheet resistances as low as 1 × 10{sup −3} Ω cm and 75 Ω/sq, respectively. The high mobility also enabled a high transmittance (T) of 88%-96% at 550 nm for the UVLC films. In addition, HAZE measurement shows AZO film scattering transmittance as low as 1.8%, which is superior over most other solution deposited transparent electrode alternatives such as silver nanowires. Thus, AZO films produced by the UVLC technique have a combined figure of merit for electrical conductivity, optical transparency, and optical HAZE higher than other solution based deposition techniques and comparable to vacuumed based deposition methods.

  11. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    International Nuclear Information System (INIS)

    Poly(vinyl alcohol), PVA, produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to those of polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion rate of the electrolyte across the PVA film to the indium tin oxide (ITO) electrode. In particular, a solvent with a hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method of forming an electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using the conducting polymer, PPy. Then, by applying a similar technique, we fabricated poly(3,4-ethylenedioxythiophene), PEDOT/PVA, composite films and investigated their basic electrochemical properties. Moreover, in this study, in order to develop a novel cell-culture system which makes it possible to communicate with cultured cells, fibroblasts were cultured on PPy- and PEDOT-coated ITO conductive glass plates for 7 days. The result reveals that the PPy and PEDOT films support the secretory functions of the cells cultured on its surface. The PPy- and PEDOT-coated electrodes may be useful to culture the cells on.

  12. Fabrication of conductive polymer nanofibers through SWNT supramolecular functionalization and aqueous solution processing

    Science.gov (United States)

    Naeem, Fahim; Prestayko, Rachel; Saem, Sokunthearath; Nowicki, Lauren; Imit, Mokhtar; Adronov, Alex; Moran-Mirabal, Jose M.

    2015-10-01

    Polymeric thin films and nanostructured composites with excellent electrical properties are required for the development of advanced optoelectronic devices, flexible electronics, wearable sensors, and tissue engineering scaffolds. Because most polymers available for fabrication are insulating, one of the biggest challenges remains the preparation of inexpensive polymer composites with good electrical conductivity. Among the nanomaterials used to enhance composite performance, single walled carbon nanotubes (SWNTs) are ideal due to their unique physical and electrical properties. Yet, a barrier to their widespread application is that they do not readily disperse in solvents traditionally used for polymer processing. In this study, we employed supramolecular functionalization of SWNTs with a conjugated polyelectrolyte as a simple approach to produce stable aqueous nanotube suspensions, that could be effortlessly blended with the polymer poly(ethyleneoxide) (PEO). The homogeneous SWNT:PEO mixtures were used to fabricate conductive thin films and nanofibers with improved conductivities through drop casting and electrospinning. The physical characterization of electrospun nanofibers through Raman spectroscopy and SEM revealed that the SWNTs were uniformly incorporated throughout the composites. The electrical characterization of SWNT:PEO thin films allowed us to assess their conductivity and establish a percolation threshold of 0.1 wt% SWNT. Similarly, measurement of the nanofiber conductivity showed that the electrospinning process improved the contact between nanotube complexes, resulting in conductivities in the S m-1 range with much lower weight loading of SWNTs than their thin film counterparts. The methods reported for the fabrication of conductive nanofibers are simple, inexpensive, and enable SWNT processing in aqueous solutions, and offer great potential for nanofiber use in applications involving flexible electronics, sensing devices, and tissue engineering

  13. Characterization of poly(3,4-ethylenedioxythiophene):tosylate conductive polymer microelectrodes for transmitter detection

    DEFF Research Database (Denmark)

    Larsen, Simon T.; Vreeland, Richard F.; Heien, Michael L.;

    2012-01-01

    In this paper we investigate the physical and electrochemical properties of micropatterned poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:tosylate) microelectrodes for neurochemical detection. PEDOT:tosylate is a promising conductive polymer electrode material for chip-based bioanalytical...... applications such as capillary electrophoresis, high-performance liquid chromatography, and constant potential amperometry at living cells. Band electrodes with widths down to 3 μm were fabricated on polymer substrates using UV lithographic methods. The electrodes are electrochemically stable in a range...

  14. Kinetic factors determining conducting filament formation in solid polymer electrolyte based planar devices

    Science.gov (United States)

    Krishnan, Karthik; Aono, Masakazu; Tsuruoka, Tohru

    2016-07-01

    Resistive switching characteristics and conducting filament formation dynamics in solid polymer electrolyte (SPE) based planar-type atomic switches, with opposing active Ag and inert Pt electrodes, have been investigated by optimizing the device configuration and experimental parameters such as the gap distance between the electrodes, the salt inclusion in the polymer matrix, and the compliance current applied in current-voltage measurements. The high ionic conductivities of SPE enabled us to make scanning electron microscopy observations of the filament formation processes in the sub-micrometer to micrometer ranges. It was found that switching behaviour and filament growth morphology depend strongly on several kinetic factors, such as the redox reaction rate at the electrode-polymer interfaces, ion mobility in the polymer matrix, electric field strength, and the reduction sites for precipitation. Different filament formations, resulting from unidirectional and dendritic growth behaviours, can be controlled by tuning specified parameters, which in turn improves the stability and performance of SPE-based devices.Resistive switching characteristics and conducting filament formation dynamics in solid polymer electrolyte (SPE) based planar-type atomic switches, with opposing active Ag and inert Pt electrodes, have been investigated by optimizing the device configuration and experimental parameters such as the gap distance between the electrodes, the salt inclusion in the polymer matrix, and the compliance current applied in current-voltage measurements. The high ionic conductivities of SPE enabled us to make scanning electron microscopy observations of the filament formation processes in the sub-micrometer to micrometer ranges. It was found that switching behaviour and filament growth morphology depend strongly on several kinetic factors, such as the redox reaction rate at the electrode-polymer interfaces, ion mobility in the polymer matrix, electric field strength

  15. Injection molded chips with integrated conducting polymer electrodes for electroporation of cells

    DEFF Research Database (Denmark)

    Andresen, Kristian; Hansen, Morten; Matschuk, Maria;

    2010-01-01

    We present the design-concept for an all polymer injection molded single use microfluidic device. The fabricated devices comprise integrated conducting polymer electrodes and Luer fitting ports to allow for liquid and electrical access. A case study of low voltage electroporation of biological...... cells in suspension is presented. The working principle of the electroporation device is based on a focusing of the electric field by means of a constriction in the flow channel for the cells. We demonstrate the use of AC voltage for electroporation by applying a 1 kHz, +/- 50 V square pulse train...

  16. Enhancement of Li+ ion conductivity in solid polymer electrolytes using surface tailored porous silica nanofillers

    Science.gov (United States)

    Mohanta, Jagdeep; Singh, Udai P.; Panda, Subhendu K.; Si, Satyabrata

    2016-09-01

    The current study represents the design and synthesis of polyethylene oxide (PEO)-based solid polymer electrolytes by solvent casting approach using surface tailored porous silica as nanofillers. The surface tailoring of porous silica nanostructure is achieved through silanization chemistry using 3-glycidyloxypropyl trimethoxysilane in which silane part get anchored to the silica surface whereas epoxy group get stellated from the silica surface. Surface tailoring of silica with epoxy group increases the room temperature electrochemical performances of the resulting polymer electrolytes. Ammonical hydrolysis of organosilicate precursor is used for both silica preparation and their surface tailoring. The composite solid polymer electrolyte films are prepared by solution mixing of PEO with lithium salt in presence of silica nanofillers and cast into film by solvent drying, which are then characterized by impedance measurement for conductivity study and wide angle x-ray diffraction for change in polymer crystallinity. Room temperature impedance measurement reveals Li+ ion conductivity in the order of 10‑4 S cm‑1, which is correlated to the decrease in PEO crystallinity. The enhancement of conductivity is further observed to be dependent on the amount of silica as well as on their surface characteristics.

  17. Electrochromic conductive polymer fuses for hybrid organic/inorganic semiconductor memories

    Science.gov (United States)

    Möller, Sven; Forrest, Stephen R.; Perlov, Craig; Jackson, Warren; Taussig, Carl

    2003-12-01

    We demonstrate a nonvolatile, write-once-read-many-times (WORM) memory device employing a hybrid organic/inorganic semiconductor architecture consisting of thin film p-i-n silicon diode on a stainless steel substrate integrated in series with a conductive polymer fuse. The nonlinearity of the silicon diodes enables a passive matrix memory architecture, while the conductive polyethylenedioxythiophene:polystyrene sulfonic acid polymer serves as a reliable switch with fuse-like behavior for data storage. The polymer can be switched at ˜2 μs, resulting in a permanent decrease of conductivity of the memory pixel by up to a factor of 103. The switching mechanism is primarily due to a current and thermally dependent redox reaction in the polymer, limited by the double injection of both holes and electrons. The switched device performance does not degrade after many thousand read cycles in ambient at room temperature. Our results suggest that low cost, organic/inorganic WORM memories are feasible for light weight, high density, robust, and fast archival storage applications.

  18. Inorganic backbone ionomers: Design and dielectric response of single-ion conducting polymers

    Science.gov (United States)

    Bartels, Joshua

    Ion-conducting polymers were studied primarily through the use of dielectric spectroscopy. The conclusions drawn from ion conduction models of the dielectric data are corroborated by additional independent experiments, including x-ray scattering, calorimetry, prism coupling, and DFT calculations. The broad concern of this dissertation is to understand and clarify a path forward in ion conducting polymer research. This is achieved by considering low-Tg ionomers and the advantages imparted by siloxane and phosphazene backbones. The most successful dielectric spectroscopy model for the materials studied is the electrode polarization model (EP), whereas other models, such as the Dyre random barrier model, fail to describe the experimental results. Seven nonionic ether oxygen (EO) containing polymers were studied in order to observe the effect that backbone chemistry has on dipole motion. Conventional carboncarbon backbone EO-containing polymers show no distinct advantage over similar EO-pendant polysiloxane or polyphosphazene systems. The mobility and effective backbone Tg imparted by the inorganic backbones are comparable. A short EO pendant results in a lower static dielectric constant due to restricted motion of dipoles close to the chain. The flexibility and chemical versatility of inorganic backbone polymers motivates further study of two ionomer systems. A polypohosphazene iodide conducting system was characterized by dielectric spectroscopy and x-ray scattering. Two end "tail" functionalization of the ammonium ion were used, a tail with two EOs and an alkyl tail of six carbons. This functional group plays an important role in ion dynamics and can wrap around the ion and self-solvate when EOs are present. The iodide-ammonium ionomers are observed to have unusually large high-frequency dielectric constants due to atomic polarization of ions. The strength of the atomic polarization scales with ion content. The aggregation state of ions is able to be determined from

  19. Ionic Conductivity of PEMA-LiClO4 Polymer Electrolytes

    International Nuclear Information System (INIS)

    Solid polymer electrolytes comprised of various weight percent ratios of poly(ethyl methacrylate) (PEMA) and lithium perchlorate (LiClO4) salt were prepared via solution casting technique using N,N-dimethylformamide (DMF) as the solvent. The conductivity values of the electrolytes were determined via impedance spectroscopy. The conductivity of the PEMA-LiClO4 electrolytes increased with increasing salt concentration and the highest conductivity obtained was in the order of 10-6 S cm-1 at salt concentration of 20 wt %. The conductivity decreased for higher salt concentration. In order to understand the conductivity behavior, XRD and dielectric studies were done. The results showed that the conductivity was influenced by the fraction of amorphous region and number of charge carriers in the system. The transference number measurement was also performed on the highest conducting electrolyte systems. The result of the measurement indicated that the systems were ionic conductors. (author)

  20. Counter electrodes from conducting polymer intercalated graphene for dye-sensitized solar cells

    Science.gov (United States)

    Li, Ru; Tang, Qunwei; Yu, Liangmin; Yan, Xuefeng; Zhang, Zhiming; Yang, Peizhi

    2016-03-01

    Creation of cost-effective and platinum-free counter electrodes (CEs) is persistent for developing advanced dye-sensitized solar cells (DSSCs). We present here the fabrication of conducting polymers such as polyaniline (PANi), polypyrole (PPy), or poly(3,4-ethylenedioxythiophene) (PEDOT) intercalated reduced graphene oxide (rGO) CEs on flexible Ti foil or polyethylene-terephthalate substrate for liquid-junction DSSC applications. The ration architecture integrates the high electron-conducting ability of graphene and good electrocatalytic activity of a conducting polymer into a single CE material. The preliminary results demonstrate that the resultant CEs follow an order of rGO/PPy > rGO/PANi > rGO/PEDOT > rGO. A maximal cell efficiency of 6.23% is determined on the optimized solar cell device, yielding 104.9% enhancement in comparison to rGO based device.

  1. Fabrication and Testing of a Bi-Conductive Polymer Membrane Fuel Cell

    International Nuclear Information System (INIS)

    This paper reports the fabrication process and testing of a bi-conductive polymer membrane (BCPM) fuel cell that integrates lateral current collectors on both sides with an ionic conductive path through the membrane. The new membrane shows major advantages over standard Nafion® membranes used in Polymer Electrolyte Fuel Cells (PEMFCs). In addition to being mechanically stable when wet, the flexible BCPM integrates efficient thin film current collectors (ICCs) on an ionic conductive membrane with a high active area ratio. Also, ICCs leave all the surface of the electrode free to eventually integrate a more efficient water and gas management system than traditional gas diffusion layers. Moreover, the fabricated membrane has shown superior volumetric power density than standard PEMFC (0.76 vs 0.47 mW/cm2μm)

  2. Conducting Polymer Coated Graphene Oxide Electrode for Rechargeable Lithium-Sulfur Batteries.

    Science.gov (United States)

    Lee, Hee-Yoon; Jung, Yongju; Kim, Seok

    2016-03-01

    Poly(diallyldimethylammonium chloride) (PDDA)/graphene oxide-sulfur composites were prepared by a chemical oxidation method. For the PDDA-GO composites, conducting polymers (PDDA) were coated on the surface of GO sheets. PDDA-GO composites could be expected to increase electrical conductivity and protect restacking of graphene sheets. And then, sulfur particles were dispersed into the PDDA-GO composites by mixing in the CS2 solvent. It is expected the PDDA-GO/S composites show the limited release of polysulfides due to the fact that it can provide high surface area, because conducting polymer can be used as spacer between graphene sheets. Electrochemical performances of prepared composites were characterized by cyclic voltammetry (CV). The PDDA-GO/S composites showed a high discharge capacity of 1102 mAh g(-1) at the first cycle and a good cycle retention of 60% after 100 cycles. PMID:27455691

  3. Ion-beam modifications of the surface morphology and conductivity in some polymer thin films

    Indian Academy of Sciences (India)

    M Ramakrishna Murthy; E Venkateshwar Rao

    2002-10-01

    Studies on the surface micromorphology and surface conductivity in thin polymer films of poly vinyl alcohol (PVA) and poly ethylene oxide (PEO) in both as-grown and ion-implanted polymer films have been carried out to reveal certain specific features of the ordered state in these materials. Optical microscopic investigations revealed the existence and enhanced formation in number of spherulites and dendrites in ionimplanted films relative to the as-grown films. The number and rate of formation of spherulites indicated an increase in the degree of crystallinity in these films. Measurements of surface conductivity of as-grown and ion-implanted polymer films, employing four-point probe method, indicated a decrease in electrical conductivity on ion-implantation. Photomicrographic analysis of the PVA and PEO thin film surfaces, has enabled to propose a temperature–stress induced mechanism of crystallization in conjunction with the surface conductivity measurements. The decrease in surface conductivity on ion-implantation in both PVA and PEO thin films, is attributed to a decrease in mobility of macromolecular charged species due to an increase in degree of crystallinity as has been observed by optical microscopy.

  4. Conductivity and Structural Studies of Plasticised Polyacrylonitrile (PAN)-Lithium Triflate Polymer Electrolyte Films

    International Nuclear Information System (INIS)

    The effect of different plasticizers on the properties of PAN-LiCF3SO3 polymer electrolytes has been studied. Propylene carbonate (PC) and ethylene carbonate (EC) having different values of donor numbers, dielectric constant and viscosity have been used as plasticizers. The highest room temperature conductivity for the film in the PAN-LiCF3SO3 system was 3.04 x 10-4 S cm-1. The highest room temperature conductivity for the films in the PAN-EC-LiCF3SO3 system and the PAN-PC-LiCF3SO3 system was 1.32 x 10-3 and 8.64 x 10-4 S cm-1. The addition of plasticizers has been found to enhance the conductivity of polymer electrolytes by increasing the amorphous content as well as by dissociating the ion aggregates present in polymer electrolyte. Conductivity temperature-dependence studies of these plasticised PAN-salt systems were carried out in the temperature range of 303 to 373 K. The conductivity versus temperature plots obeyed an Arrhenius type variation. The structural and complex formations were studied by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. (author)

  5. Persistence of slow dynamics in Tb(OETAP)2 single molecule magnets embedded in conducting polymers

    Science.gov (United States)

    Orlando, T.; Filibian, M.; Sanna, S.; Giménez-Agullo, N.; Sáenz de Pipaón, C.; Ballester, P.; Galán-Mascarós, J. R.; Carretta, P.

    2016-09-01

    The spin dynamics of Tb(OETAP)2 single ion magnets was investigated by means of muon spin relaxation (μSR) both in the bulk material as well as when the molecule is embedded into PEDOT:PSS polymer conductor. The spin fluctuation time is characterized by a high temperature activated trend, with an energy barrier around 320 K, and by a low temperature tunneling regime. When the single ion magnet is embedded into the polymer the energy barrier only slightly decreases and the fluctuation time remains of the same order of magnitude, even at low temperature. This finding shows that these single molecule magnets preserve their characteristics which, if combined with those of the conducting polymer, result in a hybrid material of potential interest for organic spintronics.

  6. Electrically Conductive, Optically Transparent Polymer/Carbon Nanotube Composites and Process for Preparation Thereof

    Science.gov (United States)

    Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  7. Conductivity and properties of polysiloxane-polyether cluster-LiTFSI networks as hybrid polymer electrolytes

    Science.gov (United States)

    Boaretto, Nicola; Joost, Christine; Seyfried, Mona; Vezzù, Keti; Di Noto, Vito

    2016-09-01

    This report describes the synthesis and the properties of a series of polymer electrolytes, composed of a hybrid inorganic-organic matrix doped with LiTFSI. The matrix is based on ring-like oligo-siloxane clusters, bearing pendant, partially cross-linked, polyether chains. The dependency of the thermo-mechanic and of the transport properties on several structural parameters, such as polyether chains' length, cross-linkers' concentration, and salt concentration is studied. Altogether, the materials show good thermo-mechanical and electrochemical stabilities, with conductivities reaching, at best, 8·10-5 S cm-1 at 30 °C. In conclusion, the cell performances of one representative sample are shown. The scope of this report is to analyze the correlations between structure and properties in networked and hybrid polymer electrolytes. This could help the design of optimized polymer electrolytes for application in lithium metal batteries.

  8. Increase in Electrical Conductivity of MOF to Billion-Fold upon Filling the Nanochannels with Conducting Polymer.

    Science.gov (United States)

    Dhara, Barun; Nagarkar, Sanjog S; Kumar, Jitender; Kumar, Vikash; Jha, Plawan Kumar; Ghosh, Sujit K; Nair, Sunil; Ballav, Nirmalya

    2016-08-01

    Redox-active pyrrole (Py) monomers were intercalated into 1D nanochannels of [Cd(NDC)0.5(PCA)]·Gx (H2NDC = 2,6-napthalenedicarboxylic acid, HPCA = 4-pyridinecarboxylic acid, G = guest molecules) (1) - a fluorescent 3D MOF (λem = 385 nm). Subsequent activation of 1⊃Py upon immersing into iodine (I2) solution resulted in an increment of the bulk electrical conductivity by ∼9 orders of magnitude. The unusual increase in conductivity was attributed to the formation of highly oriented and conducting polypyrrole (PPy) chains inside 1D nanochannels and specific host-guest interaction in 1⊃PPy thereof. The Hall-effect measurements suggested 1⊃PPy to be an n-type semiconductor material with remarkably high-carrier density (η) of ∼1.5 × 10(17) cm(-3) and mobility (μ) of ∼8.15 cm(2) V(-1) s(-1). The fluorescence property of 1 was almost retained in 1⊃PPy with concomitant exciplex-type emission at higher wavelength (λem = 520 nm). The here-presented results on [MOF⊃Conducting Polymer] systems in general will serve as a prototype experiment toward rational design for the development of highly conductive yet fluorescent MOF-based materials for various optoelectronic applications. PMID:27404432

  9. Protection of Conductive and Non-conductive Advanced Polymer-based Paints from Highly Aggressive Oxidative Environments

    Science.gov (United States)

    Gudimenko, Y.; Ng, R.; Iskanderova, Z.; Kleiman, J.; Grigorevsky, A.; Kiseleva, L.; Finckenor, M.; Edwards, D.

    2005-01-01

    Research has been continued to further improve the space durability of conductive and non-conductive polymer-based paints and of conductive thermal control paints for space applications. Efforts have been made to enhance the space durability and stability of functional Characteristics in ground-based space environment imitating conditions, using specially developed surface modification treatment. The results of surface modification of new conductive paints, including the ground-based testing in aggressive oxidative environments, such as atomic oxygen/UV and oxygen plasma, and performance evaluation are presented. Functional properties and performance characteristics, such as thermal optical properties (differential solar absorptance and thermal emittance representing the thermal optical performance of thermal control paints) and surface resistivity characteristics of pristine, surface modified, and tested materials were verified. Extensive surface analysis studies have been performed using complementary surface analyses including SEM/EDS and XPS. Test results revealed that the successfully treated materials exhibit reduced mass loss and no surface morphology change, thus indicating good protection from the severe oxidative environment. It was demonstrated that the developed surface modification treatment could be applied successfully to charge dissipative and conductive paints.

  10. Increase in Electrical Conductivity of MOF to Billion-Fold upon Filling the Nanochannels with Conducting Polymer.

    Science.gov (United States)

    Dhara, Barun; Nagarkar, Sanjog S; Kumar, Jitender; Kumar, Vikash; Jha, Plawan Kumar; Ghosh, Sujit K; Nair, Sunil; Ballav, Nirmalya

    2016-08-01

    Redox-active pyrrole (Py) monomers were intercalated into 1D nanochannels of [Cd(NDC)0.5(PCA)]·Gx (H2NDC = 2,6-napthalenedicarboxylic acid, HPCA = 4-pyridinecarboxylic acid, G = guest molecules) (1) - a fluorescent 3D MOF (λem = 385 nm). Subsequent activation of 1⊃Py upon immersing into iodine (I2) solution resulted in an increment of the bulk electrical conductivity by ∼9 orders of magnitude. The unusual increase in conductivity was attributed to the formation of highly oriented and conducting polypyrrole (PPy) chains inside 1D nanochannels and specific host-guest interaction in 1⊃PPy thereof. The Hall-effect measurements suggested 1⊃PPy to be an n-type semiconductor material with remarkably high-carrier density (η) of ∼1.5 × 10(17) cm(-3) and mobility (μ) of ∼8.15 cm(2) V(-1) s(-1). The fluorescence property of 1 was almost retained in 1⊃PPy with concomitant exciplex-type emission at higher wavelength (λem = 520 nm). The here-presented results on [MOF⊃Conducting Polymer] systems in general will serve as a prototype experiment toward rational design for the development of highly conductive yet fluorescent MOF-based materials for various optoelectronic applications.

  11. Conductivity of microfibrillar polymer-polymer composites with CNT-loaded microfibrils or compatibilizer: A comparative study

    Directory of Open Access Journals (Sweden)

    S. Fakirov

    2013-07-01

    Full Text Available Conductive polymer composites have wide ranging applications, but when they are produced by conventional melt blending, high conductive filler loadings are normally required, hindering their processability and reducing mechanical properties. In this study, two types of polymer-polymer composites were studied: i microfibrillar composites (MFC of polypropylene (PP and 5 wt% carbon nanotube (CNT loaded poly(butylene terephthalate (PBT as reinforcement, and ii maleic anhydride-grafted polypropylene (PP-g-MA compatibilizer, loaded with 5 wt% CNTs introduced into an MFC of PP and poly(ethylene terephthalate (PET in concentrations of 5 and 10 wt%. For the compatibilized composite type, PP and PET were melt-blended, cold-drawn and pelletized, followed by dry-mixing with PP-g-MA/CNT, re-extrusion at 200°C, and cold-drawing. The drawn blends produced were compression moulded to produce sheets with MFC structure. Using scanning electron microscopy, CNTs coated with PP-g-MA could be observed at the interface between PP matrix and PET microfibrils in the compatibilized blends. The volume resistivities tested by four-point test method were: 2.87•108 and 9.93•107 Ω•cm for the 66.5/28.5/5 and 63/27/10 (by wt% PP/PET/(PP-g-MA/CNT blends, corresponding to total CNT loadings (in the composites of 0.07 vol% (0.24 wt% and 0.14 vol% (0.46 wt%, respectively. For the non-compatibilized MFC types based on PP/(PBT/CNT with higher and lower melt flow grades of PP, the resistivities of 70/(95/5 blends were 1.9•106 and 1.5•107 Ω•cm, respectively, corresponding to a total filler loading (in the composite of 0.44 vol% (1.5 wt% in both MFCs.

  12. Conducting polymer actuator based on chemically deposited polypyrrole and polyurethane-based solid polymer electrolyte working in air

    International Nuclear Information System (INIS)

    Conducting polymers (CPs), such as polypyrrole, polythiophene, and polyaniline, are unique in that they have switchable properties due to their two or more mechanically stable oxidation states. Thus, their films or coatings can be easily switched by the application of a small voltage and current to change their volume during electrochemical redox processes. In particular, polypyrrole (PPy) has been studied most extensively because of its high electrical conductivity and good environmental stability under ambient conditions. In this work, we have studied a new CP actuator, fully polymeric, assembled with two PPy film electrodes and a solid polymer electrolyte (SPE), polyurethane/Mg(ClO4)2. Polyurethanes (PUs) were synthesized from 4,4'-diphenylmethane diisocyanate (MDI), 1,4-butanediol (1,4-BD) and three types of polyol: poly(ethylene glycol) (PEG), poly(propylene glycol) (PPG), and PPG-block-PEG-block-PPG (PPG-co-PEG). The chemical polymerization of PPy by immersion in Py monomer aqueous solution and oxidant aqueous solution is an adequate method to prepare PU/PPy composite film as an actuator. To find the proper thickness of the PPy coating layer for actuation, we measured the displacements of the actuators according to the thickness of the PPy coating layer. The displacement of all actuators is discussed in connection with the properties of the SPE and PPy. All the results obtained in this work show the feasibility of electrochemomechanical devices based on PPy and SPE film being able to work in air

  13. Exploiting the colloidal nanocrystal library to construct electronic devices

    Science.gov (United States)

    Choi, Ji-Hyuk; Wang, Han; Oh, Soong Ju; Paik, Taejong; Sung, Pil; Sung, Jinwoo; Ye, Xingchen; Zhao, Tianshuo; Diroll, Benjamin T.; Murray, Christopher B.; Kagan, Cherie R.

    2016-04-01

    Synthetic methods produce libraries of colloidal nanocrystals with tunable physical properties by tailoring the nanocrystal size, shape, and composition. Here, we exploit colloidal nanocrystal diversity and design the materials, interfaces, and processes to construct all-nanocrystal electronic devices using solution-based processes. Metallic silver and semiconducting cadmium selenide nanocrystals are deposited to form high-conductivity and high-mobility thin-film electrodes and channel layers of field-effect transistors. Insulating aluminum oxide nanocrystals are assembled layer by layer with polyelectrolytes to form high–dielectric constant gate insulator layers for low-voltage device operation. Metallic indium nanocrystals are codispersed with silver nanocrystals to integrate an indium supply in the deposited electrodes that serves to passivate and dope the cadmium selenide nanocrystal channel layer. We fabricate all-nanocrystal field-effect transistors on flexible plastics with electron mobilities of 21.7 square centimeters per volt-second.

  14. TITANIUM DIOXIDE TRIADS FOR IMPROVED CHARGE-SEPARATION USING CONDUCTIVE POLYMERS

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, T.M.; Gaylor, T.N.; de la Garza, L.; Rajh, T.

    2009-01-01

    Dye-sensitized solar cells are potentially one of the best solutions to solar energy conversion because of the low cost of required materials and production processes. Titanium dioxide (TiO2) nanoparticulate fi lms are the basis for one of these types of cells, providing large surface area for dye-sensitizer adsorption. Because TiO2 nanoparticulate fi lms develop defects caused by oxygen defi ciency, deep reactive electron traps are formed. With the addition of an enediol ligand, these electron traps are deliberately removed, enhancing the conduction of electrons within the fi lm. In this project, TiO2 nanoparticulate fi lms made by a layer-by-layer dip coating method were modifi ed with 3,4-dihydroxyphenylacetic acid (DOPAC). DOPAC binds to the titanium atoms on the surface of the nanoparticles, restoring their octahedral geometry. This restructuring of the surface shifts the spectral properties of the TiO2 to the visible spectrum and improves the separation of charges which is observed using photoelectrochemistry. Furthermore, DOPAC enables the electronic attachment of other molecules to the surface of TiO2 fi lms, such as the conductive polymer polyaniline base. This conductive polymer provides an extended separation of charges which increases photocurrent production by forming a triad with the TiO2 semiconductor through the 3,4-dihydroxyphenylacetic acid linker. The photocurrent increases due to the donor properties of the conductive polymer thereby decreasing charge pair recombination.

  15. Investigation of uniaxial stretching effects on the electrical conductivity of CNT–polymer nanocomposites

    International Nuclear Information System (INIS)

    A theoretical study is carried out to investigate the effects of uniaxial stretching on the electrical conductivity of carbon nanotube (CNT)–polymer composites using a mixed micromechanics model, which incorporates two conductivity mechanisms: electron hopping and conductive networks. The uniaxial stretching induces volume expansion of the composites, re-orientation of CNTs and a change in conductive networks, which are characterized by the variation of the CNT concentration, the CNT orientation distribution function and the percolation threshold, respectively. Modelling results demonstrate that stretching decreases the electrical conductivity of the composite in both the longitudinal and transverse directions. It is also observed that stretching has more significant effects on the electrical conductivity of the composites with a lower CNT volume fraction. Furthermore, the effects of Poisson's ratio on the electrical conductivity are also investigated. Possible reasons for the observed phenomena are interpreted. This work can be claimed to provide a theoretical prediction on the trend of the stretching effects on the electrical properties of CNT–polymer composites. (paper)

  16. Polymer Nanofibers with Outstanding Thermal Conductivity and Thermal Stability: Fundamental Linkage between Molecular Characteristics and Macroscopic Thermal Properties

    CERN Document Server

    Zhang, Teng; Luo, Tengfei

    2014-01-01

    Polymer nanofibers with high thermal conductivities and outstanding thermal stabilities are highly desirable in heat transfer-critical applications such as thermal management, heat exchangers and energy storage. In this work, we unlock the fundamental relations between the thermal conductivity and thermal stability of polymer nanofibers and their molecular characteristics by studying the temperature-induced phase transitions and thermal transport of a series of polymer nanofibers. Ten different polymer nanofibers with systematically chosen molecular structures are studied using large scale molecular dynamics simulations. We found that high thermal conductivity and good thermal stability can be achieved in polymers with rigid backbones, exemplified by {\\pi}-conjugated polymers, due to suppressed segmental rotations and large phonon group velocities. The low probability of segmental rotation does not only prevent temperature-induced phase transition but also enables long phonon mean free paths due to reduced di...

  17. Electrospinnability of bionanocomposites with high nanocrystal loadings: The effect of nanocrystal surface characteristics.

    Science.gov (United States)

    Naseri, Narges; Mathew, Aji P; Oksman, Kristiina

    2016-08-20

    This paper deals with the effect of solution properties and nanoparticle surface chemistry on the spinnability of a chitosan/polyethylene oxide (PEO) with high concentration (50wt%) of chitin and cellulose nanocrystals and the properties of the resultant nanocomposite fibers/fiber mats. Electrospinning dispersions with cellulose nanocrystals having sulphate surface groups showed poor spinnability compared to chitin nanocrystals with amide and amino groups. Chitin nanocrystal based dispersions showed good spinnability and continuous fiber formation whereas cellulose nanocrystal system showed discontinuous fibers and branching. The viscosity and surface tension are shown to impact this behavior, but conductivity did not. Poor spinnability observed for cellulose nanocrystal based fibers was attributed to the coagulation of negatively charged cellulose nanocrystals and positively charged chitosan. The study showed that the nanocrystal surface charge and interactions with the chitosan/PEO matrix have a significant impact on the spinnability of bionanocomposites. PMID:27178953

  18. Elucidation of charge storage characteristics of conducting polymer film using redox reaction

    CERN Document Server

    Contractor, Asfiya Q

    2013-01-01

    A general technique to investigate charge storage characteristics of conducting polymer films has been developed. A redox reaction is conducted on a polymer film on a rotating disk electrode under potentiostatic condition so that the rate of charging of the film equals the rate of removal of the charge by the reaction. In an experiment on polyaniline film deposited on platinum substrate, using Fe2+/Fe3+ in HCl as the redox system, the voltammogram shows five distinct linear segments (bands) with discontinuity in the slope at specific transition potentials. These bands are the same as those indicated by ESR/Raman spectroscopy with comparable transition potentials. From the dependence of the slopes of the bands on concentration of ferrous and ferric ions, it was possible to estimate the energies of the charge carrier in different bands. It is shown that the charge storage in the film is capacitive.

  19. Nanofluidic Diodes with Dynamic Rectification Properties Stemming from Reversible Electrochemical Conversions in Conducting Polymers.

    Science.gov (United States)

    Pérez-Mitta, Gonzalo; Marmisollé, Waldemar A; Trautmann, Christina; Toimil-Molares, María Eugenia; Azzaroni, Omar

    2015-12-16

    The use of solid state nanochannels as nanofluidic diodes is currently a topic of large interest in nanotechnology. Particularly, there is a focus in the development of nanochannels with surface functionalities that make them responsive to multiple environmental variables. Here, we present for the first time the construction of electrochemical potential- and pH-responsive nanofluidic diodes using a novel approach based on a controlled electrochemical polymerization of aniline on gold-coated polycarbonate asymmetric nanochannels. The polyaniline-modified nanochannels showed three different levels of reversible ionic rectification corresponding to the degrees of oxidation of the conducting polymer. Our results demonstrate that this strategy enables an accurate and reversible control of the rectification properties due to the well-defined and predictable electrochemical conversion of charged species generated on the pore walls. We envision that these results will create novel avenues to fabricate electrochemically modulated nanofluidic diodes using conducting polymers integrated into single conical nanopores.

  20. Electric-field-driven alignment of chiral conductive polymer thin films.

    Science.gov (United States)

    Tassinari, Francesco; Mathew, Shinto P; Fontanesi, Claudio; Schenetti, Luisa; Naaman, Ron

    2014-04-29

    We investigated the effect of an electric field on the alignment and structural properties of thin films of a chiral polybithiophene-based conductive polymer, functionalized with a protected l-cysteine amino acid. Thin films were obtained by exploiting both drop-casting and spin-coating procedures. The electric properties, the polarized Raman spectrum, the UV-vis spectrum, and the CD spectra were measured as a function of the electric field intensity applied during film formation. It was found that beyond the enhancement of the conductivity observed when the electric field aligns the polymer, the electric field significantly affects the chiral properties and the effect depends on the method of deposition. PMID:24731141

  1. Conductivity and characterization of plasticized polymer electrolyte based on (polyacrylonitrile-b-polyethylene glycol) copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yu-Hao; Chen, Chuh-Yung [Department of Chemical Engineering, National Cheng-Kung University, Tainan 70148 (China); Wang, Cheng-Chien [Department of Chemical and Material Engineering, Southern Taiwan University, Tainan 710 (China)

    2007-10-25

    A block copolymer polyacrylonitrile-b-polyethylene glycol was synthesized by the macroinitiator method. The copolymer mixed with a plasticizer - propylene carbonate (PC) and LiClO{sub 4} to form plasticized polymer electrolytes. FT-IR spectra show that the lithium ion interacts with the groups that contain the un-bonded electrons. The results of FT-IR also indicate that the EO segment can improve the dissociation of lithium salt. The differential scanning calorimeter (DSC) used to study the thermal behaviors of different compositions. In this study, the conductivity increases with the content of PEG. Additionally, the plasticized polymer electrolyte based on the block copolymer has a good conductivity and can retain good mechanical strength. (author)

  2. Electrosynthesis and absorbance spectra of TiO2 nanoparticles dispersed in the conductive polymer

    International Nuclear Information System (INIS)

    Poly ortho aminophenol (POAP)/nanocrystalline TiO2 composite were electrodeposited from through cyclic voltammetry scans to afford conductive polymer/TiO2 nanocomposite. Polymerization of ortho aminophenol (OAP) proceeded after ultrasonic irradiation of nanocrystalline TiO2. The aggregation of nano TiO2 can be reduced under ultrasonic irradiation, and the nanoparticles can be redispersed in the aqueous solution. The presence of nanocrystalline TiO2 strengthens the UV absorption of POAP and leads to a blue shift of the π-polaron absorption of POAP. Experimental absorbance spectra of TiO2/conductive polymer nanocomposite compared with results that obtained from the Maxwell–Garnett theory (MGT).

  3. Responsive Gels with the Polymer Containing Alternating Naphthalene Diimide and Fluorinated Alkyl Chains: Gel Formation and Responsiveness as Well as Electrical Conductivity of Polymer Thin Films

    Institute of Scientific and Technical Information of China (English)

    罗河伟; 刘子桐; 蔡政旭; 吴刘锁; 张关心; 刘琛阳; 张德清

    2012-01-01

    A new electroactive polymer 1 with alternating NDI (naphthalene diimide) moieties and fluorinated alkyl chains was prepared and characterized. Gels of polymer 1 were formed in several solvents. Interestingly, gels of polymer 1 exhibited responsiveness toward N2H4, F and CN . Absorption and ESR spectroscopic studies revealed that such responsiveness is owing to the reduction of NDI moieties into the respective NDI'-. In addition, thin films of polymer 1 were easily prepared with spin-coating technique and the electrical conductivity of thin films reached 52.4 S/m after exposure to NeH4 vapor.

  4. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals

    Directory of Open Access Journals (Sweden)

    Parul Chawla

    2014-08-01

    Full Text Available In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO and tri-n-octylphosphine (TOP and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern–Volmer quenching constant (KSV and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor–acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe. Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications.

  5. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals.

    Science.gov (United States)

    Chawla, Parul; Singh, Son; Sharma, Shailesh Narain

    2014-01-01

    In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe) chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO) and tri-n-octylphosphine (TOP) and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene) polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern-Volmer quenching constant (K SV) and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor-acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe). Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications. PMID:25161859

  6. What conductive polymers have taught us about the meaning of education: education before innovation

    International Nuclear Information System (INIS)

    There are many scientists and engineers who made a great discovery or a breakthrough invention. What is common to them? It is that they had a chance to experience a deep impression of science and technology in their childhood. Science shows and experiment classes are extremely effective methods to help students learn the excitement of Chemistry. In this paper, I discuss the importance of education in chemistry by presenting an illustration about the development and implementation of experiment classes on conductive polymers

  7. Freeze Drying Improves the Shelf-Life of Conductive Polymer Modified Neural Electrodes

    OpenAIRE

    Mandal, Himadri S.; Richard O. Cliff; Pancrazio, Joseph J

    2015-01-01

    Coating microelectrodes with conductive polymer is widely recognized to decrease impedance and improve performance of implantable neural devices during recording and stimulation. A concern for wide-spread use of this approach is shelf-life, i.e., the electrochemical stability of the coated microelectrodes prior to use. In this work, we investigated the possibility of using the freeze-drying process in order to retain the native low impedance state and, thereby, improve the shelf-life of cond...

  8. How the type of input function affects the dynamic response of conducting polymer actuators

    International Nuclear Information System (INIS)

    There has been a growing interest in smart actuators typified by conducting polymer actuators, especially in their (i) fabrication, modeling and control with minimum external data and (ii) applications in bio-inspired devices, robotics and mechatronics. Their control is a challenging research problem due to the complex and nonlinear properties of these actuators, which cannot be predicted accurately. Based on an input-shaping technique, we propose a new method to improve the conducting polymer actuators’ command-following ability, while minimizing their electric power consumption. We applied four input functions with smooth characteristics to a trilayer conducting polymer actuator to experimentally evaluate its command-following ability under an open-loop control strategy and a simulated feedback control strategy, and, more importantly, to quantify how the type of input function affects the dynamic response of this class of actuators. We have found that the four smooth inputs consume less electrical power than sharp inputs such as a step input with discontinuous higher-order derivatives. We also obtained an improved transient response performance from the smooth inputs, especially under the simulated feedback control strategy, which we have proposed previously [X Xiang, R Mutlu, G Alici, and W Li, 2014 “Control of conducting polymer actuators without physical feedback: simulated feedback control approach with particle swarm optimization’, Journal of Smart Materials and Structure, 23]. The idea of using a smooth input command, which results in lower power consumption and better control performance, can be extended to other smart actuators. Consuming less electrical energy or power will have a direct effect on enhancing the operational life of these actuators. (paper)

  9. How the type of input function affects the dynamic response of conducting polymer actuators

    Science.gov (United States)

    Xiang, Xingcan; Alici, Gursel; Mutlu, Rahim; Li, Weihua

    2014-10-01

    There has been a growing interest in smart actuators typified by conducting polymer actuators, especially in their (i) fabrication, modeling and control with minimum external data and (ii) applications in bio-inspired devices, robotics and mechatronics. Their control is a challenging research problem due to the complex and nonlinear properties of these actuators, which cannot be predicted accurately. Based on an input-shaping technique, we propose a new method to improve the conducting polymer actuators’ command-following ability, while minimizing their electric power consumption. We applied four input functions with smooth characteristics to a trilayer conducting polymer actuator to experimentally evaluate its command-following ability under an open-loop control strategy and a simulated feedback control strategy, and, more importantly, to quantify how the type of input function affects the dynamic response of this class of actuators. We have found that the four smooth inputs consume less electrical power than sharp inputs such as a step input with discontinuous higher-order derivatives. We also obtained an improved transient response performance from the smooth inputs, especially under the simulated feedback control strategy, which we have proposed previously [X Xiang, R Mutlu, G Alici, and W Li, 2014 “Control of conducting polymer actuators without physical feedback: simulated feedback control approach with particle swarm optimization’, Journal of Smart Materials and Structure, 23]. The idea of using a smooth input command, which results in lower power consumption and better control performance, can be extended to other smart actuators. Consuming less electrical energy or power will have a direct effect on enhancing the operational life of these actuators.

  10. Structural characterization and thermally stimulated discharge conductivity (TSDC) study in polymer thin films

    Indian Academy of Sciences (India)

    V S Sangawar; R J Dhokne; A U Ubale; P S Chikhalikar; S D Meshram

    2007-04-01

    The electrical conductivity of naphthalene doped polystyrene (PS) films (≈ 61.58 m thick) was studied as a function of dopant concentration and temperature. The formation of charge transfer (CT) complexes and strong concentration dependence of carrier mobility point out that the current carriers are transported through doped polymer system via hopping among sites associated with the dopant molecules. The activation energy, a, was calculated from the graph of logvs 103/ plot within low and high temperature regions.

  11. Free-Standing, Nanopatterned Janus Membranes of Conducting Polymer-Virus Nanoparticle Arrays.

    Science.gov (United States)

    Tiu, Brylee David B; Tiu, Sicily B; Wen, Amy M; Lam, Patricia; Steinmetz, Nicole F; Advincula, Rigoberto C

    2016-06-21

    Nanostructured mesoscale materials find wide-ranging applications in medicine and energy. Top-down manufacturing schemes are limited by the smallest dimension accessible; therefore, we set out to study a bottom-up approach mimicking biological systems, which self-assemble into systems that orchestrate complex energy conversion functionalities. Inspired by nature, we turned toward protein-based nanoparticle structures formed by plant viruses, specifically the cowpea mosaic virus (CPMV). We report the formation of hierarchical CPMV nanoparticle assemblies on colloidal-patterned, conducting polymer arrays using a protocol combining colloidal lithography, electrochemical polymerization, and electrostatic adsorption. In this approach, a hexagonally close-packed array of polystyrene microspheres was assembled on a conductive electrode to function as the sacrificial colloidal template. A thin layer of conducting polypyrrole material was electrodeposited within the interstices of the colloidal microspheres and monitored in situ using electrochemical quartz crystal microbalance with dissipation (EC-QCM-D). Etching the template revealed an inverse opaline conducting polymer pattern capable of forming strong electrostatic interactions with CPMV and therefore enabling immobilization of CPMV on the surface. The CPMV-polymer films were characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Furthermore, molecular probe diffusion experiments revealed selective ion transport properties as a function of the presence of the CPMV nanoparticles on the surface. Lastly, by utilizing its electromechanical behavior, the polymer/protein membrane was electrochemically released as a free-standing film, which can potentially be used for developing high surface area cargo delivery systems, stimuli-responsive plasmonic devices, and chemical and biological sensors. PMID:27244119

  12. Influence of conductive polymer doping on the viability of cardiac progenitor cells

    OpenAIRE

    Gelmi, Amy; Kozak Ljunggren, Monika; Rafat, Mehrdad; Jager, Edwin

    2014-01-01

    Cardiac tissue engineering via the use of stem cells is the future for repairing impaired heart function that results from a myocardial infarction. Developing an optimised platform to support the stem cells is vital to realising this, and through utilising new smart materials such as conductive polymers we can provide a multi-pronged approach to supporting and stimulating the stem cells via engineered surface properties, electrical, and electromechanical stimulation. Here we present a fundame...

  13. Formation of conductive networks with both segregated and double-percolated characteristic in conductive polymer composites with balanced properties.

    Science.gov (United States)

    Zhang, Shuangmei; Deng, Hua; Zhang, Qin; Fu, Qiang

    2014-05-14

    Morphological control of conductive networks involves the construction of segregated or double-percolated conductive networks is often reported to reduce the electrical percolation threshold of conductive polymer composites (CPCs) for better balance among electrical conductivity, mechanical properties, and filler content. Herein, the construction of conductive networks with both segregated and double-percolated characteristics is achieved based on polypropylene (PP)/polyethylene (PE) and multi-wall carbon nanotubes (CNTs). CNTs were firstly dispersed in PE; then PE/CNTs were compounded with PP particles well below the melting temperature of PP. It is observed that the percolation threshold (pc) decreases with increasing PP particle size (size 3.6 mm, pc=0.08 wt %), which agrees with previous theoretical prediction and experiment in much smaller particle size range. To further study this, the amount of CNTs in PE is varied. It is shown that the degree of PE/CNTs coating on PP particles varies with CNTs as well as PE content in these composites, and have significant influence on the final electrical property. Furthermore, a model combines classical percolation theory and model for segregated network has been proposed to analyze the effect of particle size, degree of coating and thickness of coating on the percolation behavior of these CPCs. In such a model the percolation of CNTs in PE phase as well as PENT phase in the segregated structure can be described. Overall, through such method, a much better balance among mechanical property, conductivity, and filler content is achieved in these CPCs comparing with the results in literature. PMID:24745303

  14. Copper-ion conducting solid-polymer electrolytes based on polyacrylonitrile (PAN)

    Energy Technology Data Exchange (ETDEWEB)

    Perera, Kumudu; Dissanayake, M.A.K.L.; Bandaranayake, P.W.S.K. [University of Peradeniya (Slovakia). Dept. of Physics

    2000-07-01

    Two copper-ion conducting solid-polymer electrolyte systems based on polyacrylonitrile (PAN) have been synthesized and characterized using DC polarization tests and impedance measurements. The system with 21 mol% PAN: 30 mol% EC: 45 mol% PC: 04 mol% CuCNS has a room temperature conductivity of 3.30 x 10{sup -5} S cm{sup -1} and an activation energy of 0.25 eV. The conductivity versus temperature plot obeys an Arrhenius type variation. It is predominantly an ionic conductor with negligible electronic conductivity. It has a high anionic transference number (t = 0.80) due to CNS{sup -} ions and a low cationic transference number (t{sub +} = 0.20) due to Cu{sup +} ions. The system with 20 mol% PAN: 41 mol% EC: 34 mol% PC: 5 mol% CuTf has a room temperature conductivity of 4.10 x l0{sup -3} S cm{sup -1} and an activation energy of 0.14 eV. It obeys the VTF equation. The system appears to be a mixed conductor with a cationic (Cu{sup 2+}/ Cu{sup +}) transference number of t{sub +} = 0.50 and an electronic transference number of t{sub e} = 0.50 with negligible anionic conductivity. Both systems yielded free standing stable polymer electrolyte films (Author)

  15. Nanocrystal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Tisdale, William; Prins, Ferry; Weidman, Mark; Beck, Megan

    2016-11-01

    A method of preparing monodisperse MX semiconductor nanocrystals can include contacting an M-containing precursor with an X donor to form a mixture, where the molar ratio between the M containing precursor and the X donor is large. Alternatively, if additional X donor is added during the reaction, a smaller ratio between the M containing precursor and the X donor can be used to prepare monodisperse MX semiconductor nanocrystals.

  16. Effects of plasticization on ionic conductivity enhancement of crosslinked polymer electrolyte membrane

    Science.gov (United States)

    He, Ruixuan; Kyu, Thein; Kyu's Team, Dr.

    Glass transition temperatures (Tg) of solid polymer electrolyte membranes (PEM), comprised of polyethylene glycol diacrylate (PEGDA) prepolymer, lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt, and succinonitrile (SCN) plasticizer, were systematically examined before and after crosslinking in the isotropic region guided by their ternary phase diagram. With increasing LiTFSI concentration, the Tg of uncured binary PEGDA/LiTFSI mixture increases drastically due to molecular complexation between lithium cation and ether oxygen, but ionic conductivity is very low (conductivity. Upon adding SCN plasticizer, the Tg of PEM has significantly decreased to -60 oC and ionic conductivity also increased to the superionic conductor level of 10-3 S cm-1. The analysis of ionic conductivity vs. Tg behavior by Vogel-Tamman-Fulcher(VTF) equation revealed that this ionic conductivity enhancement is due to SCN plasticization resulting in lowering the network Tg as well as lowering the activation energy. Supported by NSF-DMR 1161070.

  17. Ionic conductivity and transport properties of poly(vinylidene fluoride-co-hexafluoropropylene)-based solid polymer electrolytes

    Science.gov (United States)

    Abreha, Merhawi; Subrahmanyam, A. R.; Siva Kumar, J.

    2016-08-01

    Polymer electrolytes containing poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) and various concentrations of lithium triflate were prepared to determine the optimal polymer-salt composition for maximum ionic conductivity. Complex formation was ascertained from X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) studies. The conductivity measurements reveal that the ionic conductivity of the polymer electrolytes containing various salt concentrations increases with temperature and obeys the Arrhenius rule. It is found that the electrolyte containing 25 wt.% of lithium triflate exhibits the highest room temperature conductivity. Moreover, Ionic transference measurements show predominance of ionic motion.

  18. Electroanalysis of NADH Using Conducting and Redox Active Polymer/Carbon Nanotubes Modified Electrodes-A Review

    Directory of Open Access Journals (Sweden)

    Shen-Ming Chen

    2008-01-01

    Full Text Available Past few decades, conducting and redox active polymers play a critical role in the development of transducers for biosensing. It has been evidenced by increasing numerous reports on conducting and redox active polymers incorporated electrodes for assay of biomolcules. This review highlights the potential uses of electrogenerated polymer modified electrodes and polymer/carbon nanotubes composite modified electrodes for electroanalysis of reduced form of nicotinamide adenine dinuceltoide (NADH. In addition, carbon electrodes modified with organic and inorganic materials as modifier have been discussed in detail for the quantification of NADH based on mediator or mediator-less methods.

  19. Synthesis and proton conductivity studies of doped azole functional polymer electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Ozden, Sehmus [Department of Chemistry, Fatih University, 34500 Bueyuekcekmece-Istanbul (Turkey); Celik, Sevim Unueguer, E-mail: sunugur@fatih.edu.t [Department of Chemistry, Fatih University, 34500 Bueyuekcekmece-Istanbul (Turkey); Bozkurt, Ayhan [Department of Chemistry, Fatih University, 34500 Bueyuekcekmece-Istanbul (Turkey)

    2010-12-01

    The development of anhydrous proton-conducting membranes is important for the operation of polymer electrolyte membrane fuel cell (PEMFC) at intermediate temperature (100-200 {sup o}C). In this work, poly(vinylbenzylchloride), PVBC was produced by free radical polymerization of 4-vinylbenzylchloride and then it was modified with 5-aminotetrazole (ATET) to obtain poly(vinylbenzylaminotetrazole), PVBC-ATET. The composition of the polymer was verified by elemental analysis (EA) and the structure was characterized by FT-IR and {sup 13}C NMR spectra. According to the elemental analysis result, PVBC was modified by ATET with 80% yield. The polymer was doped with trifluoromethanesulfonic acid (TA) at various molar ratios, x = 1.25, 2.5, 3.75 with respect to tetrazole unit. The proton transfer from TA to the tetrazole rings was proved with FT-IR spectroscopy. Thermogravimetry (TG) analysis showed that the samples are thermally stable up to approximately 200 {sup o}C. Differential scanning calorimetry (DSC) results illustrated the homogeneity of the materials. Cyclic voltammetry (CV) study illustrated that the electrochemical stability domain for PVBC-ATET-TA{sub 2.5} extends over 3.0 V. The proton conductivity of these materials increased with dopant concentration and the temperature. Maximum proton conductivity of PVBC-ATET-TA{sub 2.5} was found to be 0.01 S/cm at 150 {sup o}C in the anhydrous state.

  20. Transparent conductive-polymer strain sensors for touch input sheets of flexible displays

    International Nuclear Information System (INIS)

    A transparent conductive polymer-based strain-sensor array, designed especially for touch input sheets of flexible displays, was developed. A transparent conductive polymer, namely poly(3, 4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS), was utilized owing to its strength under repeated mechanical bending. PEDOT:PSS strain sensors with a thickness of 130 nm exhibited light transmittance of 92%, which is the same as the transmittance of ITO electrodes widely used in flat panel displays. We demonstrated that the sensor array on a flexible sheet was able to sustain mechanical bending 300 times at a bending radius of 5 mm. The strain sensor shows a gauge factor of 5.2. The touch point on a flexible sheet could be detected from histograms of the outputs of the strain sensors when the sheet was pushed with an input force of 5 N. The touch input could be detected on the flexible sheet with a curved surface (radius of curvature of 20 mm). These results show that the developed transparent conductive polymer-based strain-sensor array is applicable to touch input sheets of mechanically bendable displays.

  1. A pulsed electron beam synthesis of PEDOT conducting polymers by using sulfate radicals as oxidizing species

    Science.gov (United States)

    Coletta, Cecilia; Cui, Zhenpeng; Dazzi, Alexandre; Guigner, Jean-Michel; Néron, Stéphane; Marignier, Jean-Louis; Remita, Samy

    2016-09-01

    In this study, an original radiolytic method, based on pulsed electron beam irradiation, is used for the synthesis of conducting PEDOT in an aqueous solution containing EDOT monomers in the presence of potassium persulfate, K2S2O8, at 0 °C. At this low temperature, EDOT monomers are not chemically oxidized by S2O82- anions, initiating PEDOT polymerization, but are rather oxidized by sulfate radicals, SO4•-, which are radiolytically generated by the reaction of solvated electrons, produced by water radiolysis, with persulfate anions. Successfully, as demonstrated by UV-vis absorption spectrophotometry and ATR-FTIR spectroscopy, irradiating the aqueous solution, by using a series of accumulated electron pulses, enables complete EDOT oxidation and quantitative in situ PEDOT polymerization through a step-by-step oxidation mechanism. The morphology of PEDOT polymers, mixed with unreacted K2S2O8 salt, is characterized by Cryo-TEM microscopy in aqueous solution and by SEM after deposition. Successfully, in the absence of any washing step, high resolution AFM microscopy, coupled with infrared nanospectroscopy, is used to discriminate between the organic polymers and the inorganic salt and to probe the local chemical composition of PEDOT nanostructures. The results demonstrate that PEDOT polymers form globular self-assembled nanostructures which preferentially adsorb onto unreacted K2S2O8 solid nanoplates. The present results first demonstrate the efficiency of sulfate radicals as oxidizing species for the preparation of nanostructured PEDOT polymers and second highlight the promising potentiality of electron accelerators in the field of conducting polymers synthesis.

  2. Tubular array, dielectric, conductivity and electrochemical properties of biodegradable gel polymer electrolyte

    International Nuclear Information System (INIS)

    Highlights: • A new finding of tubular array of 10–20 μm in length and 1–2 μm in thickness of gel polymer electrolyte (GPE) having 2.2 × 10−3 S cm−1 conductivity is reported. • Thermal and electrochemical characterizations of GPEs show good interaction among the polymer, plasticizer and salt. • GPE based supercapacitor demonstrates high capacitance of 186 F g−1. • Low temperature studies did not influence much on capacitance values obtained from AC impedance studies. • Charge–discharge exhibits high capacity with excellent cyclic stability and energy density. -- Abstract: A supercapacitor based on a biodegradable gel polymer electrolyte (GPE) has been fabricated using guar gum (GG) as the polymer matrix, LiClO4 as the doping salt and glycerol as the plasticizer. The scanning electron microscopy (SEM) images of the gel polymer showed an unusual tubular array type surface morphology. FTIR, DSC and TGA results of the GPE indicated good interaction between the components used. Highest ionic conductivity and lowest activation energy values were 2.2 × 10−3 S cm−1 and 0.18 eV, respectively. Dielectric studies revealed ionic behavior and good capacitance with varying frequency of the GPE system. The fabricated supercapacitor showed a maximum specific capacitance value of 186 F g−1 using cyclic voltammetry. Variation of temperature from 273 K to 293 K did not significantly influence the capacitance values obtained from AC impedance studies. Galvanostatic charge–discharge study of supercapacitor indicated that the device has good stability, high energy density and power density

  3. Ionic conductivity and dielectric permittivity of polymer electrolyte plasticized with polyethylene glycol

    Science.gov (United States)

    Das, S.; Ghosh, A.

    2016-05-01

    We have studied ionic conductivity and dielectric permittivity of PEO-LiClO4 solid polymer electrolyte plasticized with polyethylene glycol (PEG). The temperature dependence of the ionic conductivity has been well interpreted using Vogel-Tamman-Fulcher equation. The maximum dielectric constant is observed for 30 wt. % of PEG content. To get further insights into the ion dynamics, the complex dielectric permittivity has been studied with Havriliak-Negami function. The variation of relaxation time with inverse temperature obtained from HN formalism follows VTF nature.

  4. Improving the cycling stability of silicon nanowire anodes with conducting polymer coatings

    KAUST Repository

    Yao, Yan

    2012-01-01

    For silicon nanowires (Si NWs) to be used as a successful high capacity lithium-ion battery anode material, improvements in cycling stability are required. Here we show that a conductive polymer surface coating on the Si NWs improves cycling stability; coating with PEDOT causes the capacity retention after 100 charge-discharge cycles to increase from 30% to 80% over bare NWs. The improvement in cycling stability is attributed to the conductive coating maintaining the mechanical integrity of the cycled Si material, along with preserving electrical connections between NWs that would otherwise have become electrically isolated during volume changes. © 2012 The Royal Society of Chemistry.

  5. Facile preparation of transparent and conductive polymer films based on silver nanowire/polycarbonate nanocomposites

    Science.gov (United States)

    Moreno, Ivan; Navascues, Nuria; Arruebo, Manuel; Irusta, Silvia; Santamaria, Jesus

    2013-07-01

    Silver nanowires (AgNW) synthesized by a solvothermal method were incorporated into a polycarbonate matrix by a solution mixing procedure. Films with a thickness around 18 μm were obtained, showing a good distribution of the wires within the polymer matrix. The thermal stability of the polymer matrix increased significantly, with the main decomposition peak shifting up to 74 ° C for an AgNW loading of 4.35 wt%. The percolation threshold was obtained at very low AgNW content (0.04 wt%), and the composite electrical conductivity at the maximum loading (4.35 wt%) was 41.3 Ω cm. Excellent transparency was obtained at the percolation threshold, with negligible reduction in the transmittance of the polymer matrix (from 88.2 to 87.6% at 0.04 wt% loading of AgNW). In addition, the polymer matrix protected the silver nanowires from oxidation, as demonstrated by the XPS analysis.

  6. Preparation and characterization of novel nanocomposites of WS{sub 2} nanotubes and polyfluorene conductive polymer

    Energy Technology Data Exchange (ETDEWEB)

    Di Luccio, Tiziana; Borriello, Carmela; Bruno, Annalisa; Maglione, Maria Grazia; Minarini, Carla; Nenna, Giuseppe [ENEA UTTP NANO, Centro Ricerche Portici (Italy)

    2013-11-15

    Tungsten disulfide (WS{sub 2}) nanotubes are used to prepare polymer nanocomposites, similarly to other metal dichalcogenide materials, to improve lubricating and/or mechanical properties. In order to explore the possibility to extend these advantages to conductive polymers we realized new nanocomposites of WS{sub 2} nanotubes and polyfluorene conjugated polymer (WS{sub 2}/PFO). The nanocomposites were prepared from solution processing at several nanotubes concentrations. The morphological and structural analyses by SEM and XRD proved that the density of nanotubes within the polymer increased according to the preparation conditions. The successful incorporation of WS{sub 2} nanotubes was also evidenced by UV-Vis absorbance spectroscopy. The WS{sub 2}/PFO nanocomposites were tested in light emitting devices at relatively big load of nanotubes realizing a new class of devices with promising improved mechanical and thermal properties without affecting substantially the device optoelectronic performances. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Nonaligned carbon nanotubes partially embedded in polymer matrixes: a novel route to superhydrophobic conductive surfaces.

    Science.gov (United States)

    Peng, Mao; Liao, Zhangjie; Qi, Ji; Zhou, Zhi

    2010-08-17

    A new method for transforming common polymers into superhydrophobic conductive surfaces, with both a high static water contact angle (approximately 160 degrees) and a low sliding angle (2.0 degrees-4.5 degrees), and a low sheet resistance on the order of 10(1)-10(3) ohms/sq is presented. A layer of multiwalled carbon nanotubes (MWNTs) is first distributed on the surface of a polymer substrate, then by a single step of pressing, the MWNTs are partially embedded inside the substrate surface and form a superhydrophobic coating with a "carpet-" or "hair"-like morphology. The infiltration of polymer melts into the porous MWNT layer follows Darcy's law, and the pressing time greatly influence the morphology and superhydrophobicity. Moreover, the coating can be electrically heated by 20-70 degrees C with a voltage as low as 4-8 V at an electric energy density below 1.6 J/cm(2) and therefore can be used for deicing applications. Hydroxylation and fluoroalkylsilane treatment can greatly improve the stability of the superhydrophobicity of MWNTs. This method is convenient and applicable to a variety of thermoplastic polymers and nonpolymer substrates coated by silicone rubber. PMID:20695606

  8. Precision patterning of conductive polymer nanocomposite using a laser-ablated thin film

    International Nuclear Information System (INIS)

    We introduce a simple, reliable and low-cost microfabrication technique utilizing laser ablation of a thin polymer film to pattern polymer nanocomposite at a high resolution. A conductive composite of poly(dimethylsiloxane) (PDMS) and carbon nanotubes (CNTs) was selected due to their wide use in microelectromechanical systems (MEMS) and unique properties including flexibility and piezoresistivity. To pattern nanocomposite, an excimer laser ablated through a thin polyethylene terephthalate film creating mold patterns. PDMS-CNTs nanocomposite was then filled into the mold with excessive amount removed by a smooth-edged tool. Bulk PDMS was poured atop and cured. After debonding devices with relief patterns of polymer nanocomposite could be readily realized. Fabrication conditions were optimized which led to reliable patterning of various microstructures. Detailed surface profiling revealed excellent pattern authenticity and uniformity. Minimal feature size of patterns reached below 20 µm which indicated a significant improvement from prior reports. Moreover, the presented technique required only a software design to rapidly generate new patterns, thereby eliminating costly hardware such as lithography mask, stamp and clean room. Fabrication time and cost could be consequently reduced—ideal for lab prototyping purposes. Sensor examples are discussed to demonstrate versatile applications of polymer nanocomposite in MEMS. (paper)

  9. Ion-Electron-Conducting Polymer Composites: Promising Electromagnetic Interference Shielding Material.

    Science.gov (United States)

    Vyas, Manoj Kumar; Chandra, Amita

    2016-07-20

    Polymer nanocomposites consisting of poly(vinylidenefluoride-co-hexafluoropropylene) PVdF-HFP, inorganic salt (LiBF4), organic salt (EMIMBF4), multiwalled carbon nanotubes (MWCNTs), and Fe3O4 nanoparticles were prepared as electromagnetic shield material. Improvement in conductivity and dielectric property due to the introduction of EMIMBF4, LiBF4, and MWCNTs was confirmed by complex impedance spectroscopy. The highest conductivity obtained is ∼1.86 mS/cm. This is attributed to the high ionic conductivity of the ionic liquids and the formation of a connecting network by the MWCNTs facilitating electron conduction. The total electromagnetic interference (EMI) shielding effectiveness has a major contribution to it due to absorption. Although the total shielding effectiveness in the Ku band (12.4-18 GHz) of pure ion-conducting system was found to be ∼19 dB and that for the polymer composites which are mixed (ion + electron) conductors is ∼46 dB, the contributions due to absorption are ∼16 and ∼42 dB, respectively. PMID:27351810

  10. Advanced two-photon photolithography for patterning of transparent, electrically conductive ionic liquid-polymer nanostructures

    Science.gov (United States)

    Bakhtina, Natalia A.; MacKinnon, Neil; Korvink, Jan G.

    2016-04-01

    A key challenge in micro- and nanotechnology is the direct patterning of functional structures. For example, it is highly desirable to possess the ability to create three-dimensional (3D), conductive, and optically transparent structures. Efforts in this direction have, to date, yielded less than optimal results since the polymer composites had low optical transparency over the visible range, were only slightly conductive, or incompatible with high resolution structuring. We have previously presented the novel cross-linkable, conductive, highly transparent composite material based on a photoresist (IP-L 780, OrmoComp, or SU-8) and the ionic liquid 1-butyl-3-methylimidazolium dicyanamide. Material patterning by conventional and two-photon photolithography has been demonstrated as proof-of-concept. Aiming to increase the resolution and to extend the spectrum of exciting applications we continued our research into identifying new ionic liquid - polymer composites. In this paper, we report the precise 3D single-step structuring of optically transparent and electrically conductive ionic liquid - polymer nanostructures with the highest spatial resolution (down to 150 nm) achieved to date. This was achieved via the development of novel cross-linkable composite based on the photoresist IP-G 780 and the ionic liquid 1-butyl-3-methylimidazolium dicyanamide. The successful combination of the developed material with the advanced direct laser writing technique enabled the time- and cost-saving direct manufacturing of transparent, electrically conductive components. We believe that the excellent characteristics of the structured material will open a wider range of exciting applications.

  11. Ionic drift velocity measurement on hot-pressed Ag+ ion conducting glass-polymer electrolytes

    Indian Academy of Sciences (India)

    Angesh Chandra

    2015-12-01

    Ionic drift velocity (d) measurements of a new Ag+ ion conducting glass-polymer electrolytes (GPEs): (1−x) PEO : x[0.8(0.75AgI:0.25AgCl) : 0.2(Ag2 O:V2O5)], where 0 < x < 50 wt%, were reported. GPEs were casted using the hot-press techniques developed in recent times. The composition: 70PEO : 30[0.8(0.75AgI : 0.25AgCl) : 0.2(Ag2O : V2O5)] with conductivity ()∼ 7.7 × 10−7 S cm−1 was identified as highest conducting composition from the compositional-dependent conductivity studies. The ionic mobility (), mobile ion concentration (), ionic transference number (ion) and ionic drift velocity (d) of GPEs were determined at different temperatures with the help of the d.c. polarization technique and other well-known important relations.

  12. Observation of Quantized and Partial Quantized Conductance in Polymer-Suspended Graphene Nanoplatelets.

    Science.gov (United States)

    Kang, Yuhong; Ruan, Hang; Claus, Richard O; Heremans, Jean; Orlowski, Marius

    2016-12-01

    Quantized conductance is observed at zero magnetic field and room temperature in metal-insulator-metal structures with graphene submicron-sized nanoplatelets embedded in a 3-hexylthiophene (P3HT) polymer layer. In devices with medium concentration of graphene platelets, integer multiples of G o = 2e (2)/h (=12.91 kΩ(-1)), and in some devices partially quantized including a series of with (n/7) × G o, steps are observed. Such an organic memory device exhibits reliable memory operation with an on/off ratio of more than 10. We attribute the quantized conductance to the existence of a 1-D electron waveguide along the conductive path. The partial quantized conductance results likely from imperfect transmission coefficient due to impedance mismatch of the first waveguide modes. PMID:27044308

  13. Fast ultrahigh-density writing of low-conductivity patterns on semiconducting polymers.

    Science.gov (United States)

    Farina, Marco; Ye, Tengling; Lanzani, Guglielmo; di Donato, Andrea; Venanzoni, Giuseppe; Mencarelli, Davide; Pietrangelo, Tiziana; Morini, Antonio; Keivanidis, Panagiotis E

    2013-01-01

    The exceptional interest in improving the limitations of data storage, molecular electronics and optoelectronics has promoted the development of an ever increasing number of techniques used to pattern polymers at micro and nanoscale. Most of them rely on atomic force microscopy to thermally or electrostatically induce mass transport, thereby creating topographic features. Here we show that the mechanical interaction between the tip of the atomic force microscope and the surface of π-conjugated polymeric films produces a local increase of molecular disorder, inducing a localized lowering of the semiconductor conductivity, not associated to detectable modifications in the surface topography. This phenomenon allows for the swift production of low-conductivity patterns on the film surface at a speed exceeding 20 μm s⁻¹; paths have a resolution in the order of the tip size (20 nm) and are detected by a conducting-atomic force microscopy tip in the conductivity maps.

  14. Pressure-induced amorphization of a dense coordination polymer and its impact on proton conductivity

    International Nuclear Information System (INIS)

    The proton conductivity of a dense coordination polymer (CP) was investigated under high-pressure conditions. Impedance measurements under high pressures revealed that the proton conductivity of the CP decreased more than 1000-fold at pressures of 3–7 GPa and that the activation energy for proton conduction almost doubled compared with that at ambient pressure. A synchrotron X-ray study under high pressure identified the amorphization process of the CP during compression, which rationally explains the decrease in conductivity and increase in activation energy. This phenomenon is categorized as reversible pressure-induced amorphization of a dense CP and is regarded as a demonstration of the coupling of the mechanical and electrical properties of a CP

  15. Conductivity enhancement via chemical modification of chitosan based green polymer electrolyte

    International Nuclear Information System (INIS)

    The potential of carboxymethyl chitosan as a green polymer electrolyte has been explored. Chitosan produced from partial deacetylation of chitin was reacted with monochloroacetic acid to form carboxymethyl chitosan. A green polymer electrolyte based chitosan and carboxymethyl chitosan was prepared by solution-casting technique. The powder and films were characterized by reflection Fourier transform infrared (ATR-FTIR) spectroscopy, 1H nuclear magnetic resonance, elemental analysis and X-ray diffraction, electrochemical impedance spectroscopy, and scanning electron microscopy. The shift of wavenumber that represents hydroxyl and amine stretching confirmed the polymer solvent complex formation. The XRD spectra results show that chemical modification of chitosan has improved amorphous properties of chitosan. The ionic conductivity was found to increase by two magnitudes higher with the chemical modification of chitosan. The highest conductivity achieved was 3.6 × 10−6 S cm−1 for carboxymethyl chitosan at room temperature and 3.7 × 10−4 S cm−1 at 60 °C

  16. Microtexturing of the conductive PEDOT:PSS Polymer for superhydrophobic organic electrochemical transistors

    KAUST Repository

    Gentile, Francesco

    2014-01-22

    Superhydrophobic surfaces are bioinspired, nanotechnology artifacts, which feature a reduced friction coefficient, whereby they can be used for a number of very practical applications including, on the medical side, the manipulation of biological solutions. In this work, we integrated superhydrophobic patterns with the conducting polymer PEDOT:PSS, one of the most used polymers in organic electronics because highly sensitive to ionized species in solution. In doing so, we combined geometry and materials science to obtain an advanced device where, on account of the superhydrophobicity of the system, the solutions of interest can be manipulated and, on account of the conductive PEDOT:PSS polymer, the charged molecules dispersed inside can be quantitatively measured. This original substrate preparation allowed to perform electrochemical measurements on ionized species in solution with decreasing concentration down to 10 -7 molar. Moreover, it was demonstrated the ability of the device of realizing specific, combined time and space resolved analysis of the sample. Collectively, these results demonstrate how a tight, interweaving integration of different disciplines can provide realistic tools for the detection of pathologies. The scheme here introduced offers breakthrough capabilities that are expected to radically improve both the pace and the productivity of biomedical research, creating an access revolution. 2014 Francesco Gentile et al.

  17. Microtexturing of the Conductive PEDOT:PSS Polymer for Superhydrophobic Organic Electrochemical Transistors

    Directory of Open Access Journals (Sweden)

    Francesco Gentile

    2014-01-01

    Full Text Available Superhydrophobic surfaces are bioinspired, nanotechnology artifacts, which feature a reduced friction coefficient, whereby they can be used for a number of very practical applications including, on the medical side, the manipulation of biological solutions. In this work, we integrated superhydrophobic patterns with the conducting polymer PEDOT:PSS, one of the most used polymers in organic electronics because highly sensitive to ionized species in solution. In doing so, we combined geometry and materials science to obtain an advanced device where, on account of the superhydrophobicity of the system, the solutions of interest can be manipulated and, on account of the conductive PEDOT:PSS polymer, the charged molecules dispersed inside can be quantitatively measured. This original substrate preparation allowed to perform electrochemical measurements on ionized species in solution with decreasing concentration down to 10−7 molar. Moreover, it was demonstrated the ability of the device of realizing specific, combined time and space resolved analysis of the sample. Collectively, these results demonstrate how a tight, interweaving integration of different disciplines can provide realistic tools for the detection of pathologies. The scheme here introduced offers breakthrough capabilities that are expected to radically improve both the pace and the productivity of biomedical research, creating an access revolution.

  18. Integration of microwave MEMS devices into rectangular waveguide with conductive polymer interposers

    International Nuclear Information System (INIS)

    This paper investigates a novel method of integrating microwave microelectromechanical systems (MEMS) chips into millimeter-wave rectangular waveguides. The fundamental difficulties of merging micromachined with macromachined microwave components, in particular, surface topography, roughness, mechanical stress points and air gaps interrupting the surface currents, are overcome by a double-side adhesive conductive polymer interposer. This interposer provides a uniform electrical contact, stable mechanical connection and a compliant stress distribution interlayer between the MEMS chip and a waveguide frame. The integration method is successfully implemented both for prototype devices of MEMS-tuneable reflective metamaterial surfaces and for MEMS reconfigurable transmissive surfaces. The measured insertion loss of the novel conductive polymer interface is less than 0.4 dB in the E-band (60–90 GHz), as compared to a conventional assembly with an air gap of 2.5 dB loss. Moreover, both dc biasing lines and mechanical feedthroughs to actuators outside the waveguide are demonstrated in this paper, which is achieved by structuring the polymer sheet xurographically. Finite element method simulations were carried out for analyzing the influence of different parameters on the radio frequency performance. (paper)

  19. Improving the Performance of Lithium–Sulfur Batteries by Conductive Polymer Coating

    KAUST Repository

    Yang, Yuan

    2011-11-22

    Rechargeable lithium-sulfur (Li-S) batteries hold great potential for next-generation high-performance energy storage systems because of their high theoretical specific energy, low materials cost, and environmental safety. One of the major obstacles for its commercialization is the rapid capacity fading due to polysulfide dissolution and uncontrolled redeposition. Various porous carbon structures have been used to improve the performance of Li-S batteries, as polysulfides could be trapped inside the carbon matrix. However, polysulfides still diffuse out for a prolonged time if there is no effective capping layer surrounding the carbon/sulfur particles. Here we explore the application of conducting polymer to minimize the diffusion of polysulfides out of the mesoporous carbon matrix by coating poly(3,4-ethylenedioxythiophene)- poly(styrene sulfonate) (PEDOT:PSS) onto mesoporous carbon/sulfur particles. After surface coating, coulomb efficiency of the sulfur electrode was improved from 93% to 97%, and capacity decay was reduced from 40%/100 cycles to 15%/100 cycles. Moreover, the discharge capacity with the polymer coating was ∼10% higher than the bare counterpart, with an initial discharge capacity of 1140 mAh/g and a stable discharge capacity of >600 mAh/g after 150 cycles at C/5 rate. We believe that this conductive polymer coating method represents an exciting direction for enhancing the device performance of Li-S batteries and can be applicable to other electrode materials in lithium ion batteries. © 2011 American Chemical Society.

  20. Highly processable method for the construction of miniature conducting polymer moisture sensors

    Science.gov (United States)

    McGovern, Scott T.; Spinks, Geoffrey M.; Wallace, Gordon G.

    2005-02-01

    A polymer blend incorporating polyaniline (PAn) was used as a sensing medium in the construction of a resistance based humidity sensor. Aniline monomer was polymerised to PAn emeraldine salt (ES) in the presence of poly (butyl acrylate-co-vinyl acetate) and the processable blend was developed by redissolving 1-2 w/w% of the resulting sensing polymer residue in dichloromethane (DCM). Some of this residue was washed in ammonia solution to de-dope the PAn to emeraldine base (EB) to act as a protective layer on the surface of the sensing polymer. This residue was then washed with distilled water until a neutral pH was realised with the waste water, dried and redissolved in DCM at 1-2 w/w% to create a processable blend barrier polymer solution. The final sensor design utilised 125μm polyester insulated platinum wire as conducting electrodes that were dip coated in the PAn ES blend solution and dried in a desiccator. A protective coating was then applied by dip coating in the EB blend solution. The sensors had an overall final thickness of less than 200μm and showed high sensitivity to humidity, low resistance, and good reversibility without hysteresis. The EB protective layer was shown to give more stable and predictable responses to the sensors when placed inside curing epoxies. Polymer based thin film humidity sensors have the advantage that the high processability of the material allows for simple fabrication of a range of geometries including smaller sensor designs. Such sensors may find uses in detecting water content in a number of areas including composite materials, electronic textiles, food/electronics packaging and corrosion detection.

  1. Conducting polymer nanocomposites loaded with nanotubes and fibers for electrical and thermal applications

    Science.gov (United States)

    Chiguma, Jasper

    The design, fabrication and measurement of electrical and thermal properties of polymers loaded with nanotubes and fibers are the foci of the work presented in this dissertation. The resulting products of blending polymers with nanomaterials are called nanocomposites and are already finding applications in many areas of human endeavour. Among some of the most recent envisioned applications of nanocomposites is in electronic devices as thermal interface materials (TIMs). This potential application as TIMs, has been made more real by the realization that carbon nanotubes, could potentially transfer their high electrical, thermal and mechanical properties to polymers in the nanocomposites. In Chapter 1, the events leading to the discovery of carbon nanotubes are reviewed followed by an elaborate discussion of their structure and properties. The discussion of the structure and properties of carbon nanotubes help in understanding the envisaged applications. Chapter 2 focuses on the fabrication of insulating polymer nanocomposites, their electrical and mechanical properties. Poly (methyl methacrylate) (PMMA) and a polyimide formed by reacting pyromellitic dianhydride (PMDA) and 4, 4'-oxydianiline (ODA) (PMDA-ODA) nanocomposites with carbon nanotubes were prepared by in-situ polymerization. Poly (1-methyl-4-pentene) (TPX), Polycarbonate (PC), Poly (vinyl chloride) (PVC), Poly (acrylonitrile-butadiene-styrene) (ABS), the alloys ABS-PC, ABS-PVC, and ABS-PC-PVC nanocomposites were prepared from the respective polymers and carbon nanotubes and their mechanical and electrical properties measured. Chapter 3 covers the nanocomposites that were prepared by the in-situ polymerization of the conducting polymers Polyaniline (PANi), Polypyrrole (PPy) and Poly (3, 4-ethylenedioxythiophene) (PEDOT) by in-situ polymerization. These are evaluated for electrical conductivity. The use of surfactants in facilitating carbon nanotube dispersion is discussed and applied in the preparation of

  2. Effect of ZrO2 on conductivity of PVC–PMMA–LiBF4–DBP polymer electrolytes

    Indian Academy of Sciences (India)

    S Rajendran; T Uma

    2000-02-01

    The preparation and characterization of composite polymer electrolytes of PVC–PMMA–LiBF4–DBP for different concentrations of ZrO2 have been investigated. FTIR studies indicate complex formation between the polymers, salt and plasticizer. The electrical conductivity values measured by a.c. impedance spectroscopy is found to depend upon the ZrO2 concentration. The temperature dependence of the conductivity of the polymer films seems to obey the VTF relation. The conductivity values are presented and results discussed.

  3. Correlation between ionic conductivity and fluidity of polymer gel electrolytes containing NH4CF3SO3

    Indian Academy of Sciences (India)

    Harinder Pal Singh; Rajiv Kumar; S S Sekhon

    2005-08-01

    Nonaqueous polymer gel electrolytes containing ammonium triflate (NH4CF3SO3) and dimethylacetamide (DMA) with polymethylmethacrylate (PMMA) as the gelling polymer have been synthesized which show high value of conductivity (∼ 10-2 S/cm) at 25°C. The conductivity of polymer gel electrolytes containing different concentrations of NH4CF3SO3 shows a small decrease with the addition of PMMA and this has been correlated with the variation of fluidity of these gel electrolytes. The small decrease in conductivity with PMMA addition shows that polymer plays the role of stiffener and this is supported by FTIR results which also indicates the absence of any active interaction between polymer and NH4CF3SO3 in these gel electrolytes.

  4. Electromagnetic interference shielding effectiveness of nanoreinforced polymer composites deposited with conductive metallic thin films

    International Nuclear Information System (INIS)

    The effect of using conductive metallic thin films deposited on high density polyethylene (HDPE) and styrene butadiene copolymer (SBC) in conjunction with carbon nanofiber (CNF) reinforcement of HDPE and SBC was investigated in order to improve the electromagnetic interference shielding effectiveness (EMI SE) of the structures. Thin films of copper, silver and aluminum were deposited by thermal evaporation onto the polymeric matrices and its composites (0–20 wt.% of CNFs). Results show a synergistic effect of the two approaches (metallic coating and CNF reinforcement) toward improving the EMI SE. The chemical composition, surface morphology, carbon nanofiber distribution, thickness and microstructure of metallic coated polymers are examined using X-Ray Diffraction and Scanning Electron Microscopy. - Highlights: ► Metallic thin films were evaporated on carbon nanofiber reinforced polymers. ► The electromagnetic shielding effectiveness of the structures was evaluated. ► Thin films and carbon nanofibers synergistically improved the shielding effectiveness.

  5. High rate lithium-sulfur battery enabled by sandwiched single ion conducting polymer electrolyte

    Science.gov (United States)

    Sun, Yubao; Li, Gai; Lai, Yuanchu; Zeng, Danli; Cheng, Hansong

    2016-02-01

    Lithium-sulfur batteries are highly promising for electric energy storage with high energy density, abundant resources and low cost. However, the battery technologies have often suffered from a short cycle life and poor rate stability arising from the well-known “polysulfide shuttle” effect. Here, we report a novel cell design by sandwiching a sp3 boron based single ion conducting polymer electrolyte film between two carbon films to fabricate a composite separator for lithium-sulfur batteries. The dense negative charges uniformly distributed in the electrolyte membrane inherently prohibit transport of polysulfide anions formed in the cathode inside the polymer matrix and effectively blocks polysulfide shuttling. A battery assembled with the composite separator exhibits a remarkably long cycle life at high charge/discharge rates.

  6. Morphology and Electrical Conductivity of Carbon Nanocoatings Prepared from Pyrolysed Polymers

    Directory of Open Access Journals (Sweden)

    Marcin Molenda

    2014-01-01

    Full Text Available Conductive carbon nanocoatings (conductive carbon layers—CCL were formed on α-Al2O3 model support using three different polymer precursors and deposition methods. This was done in an effort to improve electrical conductivity of the material through creating the appropriate morphology of the carbon layers. The best electrical properties were obtained with use of a precursor that consisted of poly-N-vinylformamide modified with pyromellitic acid (PMA. We demonstrate that these properties originate from a specific morphology of this layer that showed nanopores (3-4 nm capable of assuring easy pathways for ion transport in real electrode materials. The proposed, water mediated, method of carbon coating of powdered supports combines coating from solution and solid phase and is easy to scale up process. The optimal polymer carbon precursor composition was used to prepare conductive carbon nanocoatings on LiFePO4 cathode material. Charge-discharge tests clearly show that C/LiFePO4 composites obtained using poly-N-vinylformamide modified with pyromellitic acid exhibit higher rechargeable capacity and longer working time in a battery cell than standard carbon/lithium iron phosphate composites.

  7. Conductivity and adhesion enhancement in low-temperature processed indium tin oxide/polymer nanocomposites

    International Nuclear Information System (INIS)

    We report on the conductivity and adhesion enhancement of indium tin oxide (In2O3:Sn; ITO) nanoparticle films by the application of polymers as matrix material. We fabricated ITO layers at a maximum process temperature of 130 oC by modifying and spin-coating nanoparticulate ITO dispersions. Dispersions containing the organic film-forming agent polyvinylpyrrolidone (PVP) and the organofunctional coupling agent 3-methacryloxypropyltrimethoxysilane (MPTS) have been developed to obtain transparent and conducting coatings on substrates which do not withstand high process temperatures like polymers or already processed glasses. The layers were cured by UV-irradiation as well as by low-temperature heat treatment (T = 130 oC) in air and under forming gas atmosphere (N2/H2). The influence of the additives on the electrical, optical, morphological and mechanical layer properties is reported. Compared to best pure ITO layers (3.1 Ω-1 cm-1), the ITO-MPTS-PVP nanocomposite coatings exhibit a conductance of 9.8 Ω-1 cm-1. Stable sheet resistances of 750 Ω/□ at a coexistent transmittance of 86% at 550 nm for a layer thickness of about 1.3 μm were achieved. The conductance enhancement is a consequence of the consolidation of the ITO nanoparticle network due to the acting shrinkage forces caused either by drying in the case of PVP or UV-irradiation induced condensation and polymerization reactions in the case of MPTS.

  8. A first approach to foot motion monitoring using conductive polymer sensors

    Science.gov (United States)

    Castano, L. M.; Winkelmann, A. E.; Flatau, A. B.

    2009-03-01

    A study was conducted of socks fitted with thin flexible conductive polymer sensors for the potential use as a smart sock for monitoring foot motion. The thin flexible sensors consisted of a conductive polymer applied on an elastic textile substrate that exhibited a resistance change when strained. Quasi-static response tests of the basic sensor over a static load range of a few Newtons were conducted and showed a time varying response as observed by previous investigators. Dynamic testing through an electrodynamic shaker shows good dynamic response at a low frequency range, less than 4Hz. Strips of 12 cm x 1 cm of the sensor on fabric showed a reproducible basal resistance on the order of 10KOhms. Other geometries of the continuous sensors and correlation of strain to resistance variation were studied. Similar tests were performed on different textile substrates which vary in composition and microstructure, i.e. woven, knitted, nylon%, polyester%, etc... These sensors were integrated into socks and preliminary results indicate that distinct responses to different foot motion patterns are detected in sensors placed at different joint locations on the foot. Further processing of strain results from smart socks should provide information about the kinematics and dynamics of the human foot.

  9. Ion conduction and relaxation in PEO-LiTFSI-Al2O3 polymer nanocomposite electrolytes

    International Nuclear Information System (INIS)

    Ion conduction and relaxation in PEO-LiTFSI-Al2O3 polymer nanocomposite electrolytes have been studied for different concentrations of Al2O3 nanoparticles. X-ray diffraction and differential scanning calorimetric studies show that the maximum amorphous phase of PEO is observed for PEO-LiTFSI embedded with 5 wt. % Al2O3. The maximum ionic conductivity ∼3.3 × 10−4 S cm−1 has been obtained for this composition. The transmission electron microscopic image shows a distribution of Al2O3 nanoparticles in all compositions with size of <50 nm. The temperature dependence of the ionic conductivity follows Vogel-Tamman-Fulcher nature, indicating a strong coupling between ionic and polymer chain segmental motions. The scaling of the ac conductivity implies that relaxation dynamics follows a common mechanism for different temperatures and Al2O3 concentrations. The imaginary modulus spectra are asymmetric and skewed toward the high frequency sides of the maxima and analyzed using Havriliak-Negami formalism. The temperature dependence of the relaxation time obtained from modulus spectra also exhibits Vogel-Tamman-Fulcher nature. The values of the stretched exponent obtained from Kohlrausch-Williams-Watts fit to the modulus data are fairly low, suggesting highly non-exponential relaxation for all concentrations of Al2O3 in these electrolytes

  10. Conductive Circuit Containing a Polymer Composition Containing Thermally Exfoliated Graphite Oxide and Method of Making the Same

    Science.gov (United States)

    Prud'Homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor)

    2014-01-01

    A conductive circuit containing a polymer composite, which contains at least one polymer and a modified graphite oxide material, containing thermally exfoliated graphite oxide having a surface area of from about 300 m(sup.2)/g to 2600 m(sup.2)/g, and a method of making the same.

  11. Effect of Eutectic Concentration on Conductivity in PEO:LiX Based Solid Polymer Electrolytes

    Science.gov (United States)

    Zhan, Pengfei; Ganapatibhotla, Lalitha; Maranas, Janna

    Polyethylene oxide (PEO) and lithium salt based solid polymer electrolytes (SPEs) have been widely proposed as a substitution for the liquid electrolyte in Li-ion batteries. As salt concentration varies, these systems demonstrate rich phase behavior. Conductivity as a function of salt concentration has been measured for decades and various concentration dependences have been observed. A PEO:LiX mixture can have one or two conductivity maximums, while some mixtures with salt of high ionic strength will have higher conductivity as the salt concentration decrease. The factors that affect the conductivity are specific for each sample. The universal factor that affects conductivity is still not clear. In this work, we measured the conductivity of a series of PEO:LiX mixtures and statistical analysis shows conductivity is affected by the concentration difference from the eutectic concentration (Δc). The correlation with Δc is stronger than the correlation with glass transition temperature. We believe that at the eutectic concentration, during the solidification process, unique structures can form which aid conduction. Currently at Dow Chemical.

  12. Preparation and study of conductivity in lithium salt complexes of mixed MEEP : PEO polymer electrolytes

    Indian Academy of Sciences (India)

    G Saibaba; D Srikanth; A Ramachandra Reddy

    2004-02-01

    Poly(ethylene oxide)–LiX complexes and poly[bis(methoxy ethoxy ethoxide) phosphazene]–LiX complexes of polymer thin films were prepared. Conductivity measurements were carried out and the values were found to lie between 10-8 and 1.7 × 10-5 (S/cm). MEEP : LiX salts showed higher conductivity than PEO–LiX salts despite lower dimensional stability. For enhancing stability and conductivity, MEEP–PEO : (LiX) systems were prepared and conductivity measurements carried out. Further the MEEP/PEO : (LiX) was doped with Al2O3 and TiO2 nanocomposite ceramic fillers and the conductivity was studied. The conductivity vs temperature plots showed the enhancement of conductivity with TiO2 added nanocomposite ceramic fillers. The enhanced conductivity is explained on the basis of the effect of local structural modification-promoting localized amorphous region-for enhancement of the Li+ ion transport.

  13. Long-term cycle stability at a high current for nanocrystalline LiFePO4 coated with a conductive polymer

    International Nuclear Information System (INIS)

    Highly uniform hierarchical-microstructured LiFePO4 particles with dumbbell- and donut-shape and individual LiFePO4 nanocrystals were prepared by a hydrothermal method utilizing citric acid or a triblock copolymer (Pluronic P123) as a surfactant. The cathode composed of the individual nanocrystalline LiFePO4 particles exhibited higher specific capacity than the cathodes composed of the hierarchically assembled microparticles. Coating a conductive polymer, poly-3,4-ethylenedioxythiophene (PEDOT), on the surface of LiFePO4 particles improved the battery performances such as large specific capacities, high rate capability and an improved cycle stability. The nanocrystalline LiFePO4 particles coated with PEDOT (20 wt%) exhibited the highest discharge capacities of 175 and 136 mAh g−1 for the first battery cycle and 163 and 128 mAh g−1 after 500 battery cycles, with a degradation rate of 6–7%, at the rates of 1 and 10 C, respectively. (paper)

  14. Long-term cycle stability at a high current for nanocrystalline LiFePO4 coated with a conductive polymer

    Science.gov (United States)

    Dinh, Hung-Cuong; Lim, Hanjo; Park, Ki Dong; Yeo, In-Hyeong; Kang, Yongku; Mho, Sun-il

    2013-03-01

    Highly uniform hierarchical-microstructured LiFePO4 particles with dumbbell- and donut-shape and individual LiFePO4 nanocrystals were prepared by a hydrothermal method utilizing citric acid or a triblock copolymer (Pluronic P123) as a surfactant. The cathode composed of the individual nanocrystalline LiFePO4 particles exhibited higher specific capacity than the cathodes composed of the hierarchically assembled microparticles. Coating a conductive polymer, poly-3,4-ethylenedioxythiophene (PEDOT), on the surface of LiFePO4 particles improved the battery performances such as large specific capacities, high rate capability and an improved cycle stability. The nanocrystalline LiFePO4 particles coated with PEDOT (20 wt%) exhibited the highest discharge capacities of 175 and 136 mAh g-1 for the first battery cycle and 163 and 128 mAh g-1 after 500 battery cycles, with a degradation rate of 6-7%, at the rates of 1 and 10 C, respectively.

  15. Reversible light-controlled conductance switching of azobenzene-based metal/polymer nanocomposites

    International Nuclear Information System (INIS)

    We present a new concept of light-controlled conductance switching based on metal/polymer nanocomposites with dissolved chromophores that do not have intrinsic current switching ability. Photoswitchable metal/PMMA nanocomposites were prepared by physical vapor deposition of Au and Pt clusters, respectively, onto spin-coated thin poly(methylmethacrylate) films doped with azo-dye molecules. High dye concentrations were achieved by functionalizing the azo groups with tails and branches, thus enhancing solubility. The composites show completely reversible optical switching of the absorption bands upon alternating irradiation with UV and blue light. We also demonstrate reversible light-controlled conductance switching. This is attributed to changes in the metal cluster separation upon isomerization based on model experiments where analogous conductance changes were induced by swelling of the composite films in organic vapors and by tensile stress.

  16. Protic Salt Polymer Membranes: High-Temperature Water-Free Proton-Conducting Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Gervasio, Dominic Francis [Univ. of Arizona, Tucson, AZ (United States)

    2010-09-30

    This research on proton-containing (protic) salts directly addresses proton conduction at high and low temperatures. This research is unique, because no water is used for proton ionization nor conduction, so the properties of water do not limit proton fuel cells. A protic salt is all that is needed to give rise to ionized proton and to support proton mobility. A protic salt forms when proton transfers from an acid to a base. Protic salts were found to have proton conductivities that are as high as or higher than the best aqueous electrolytes at ambient pressures and comparable temperatures without or with water present. Proton conductivity of the protic salts occurs providing two conditions exist: i) the energy difference is about 0.8 eV between the protic-salt state versus the state in which the acid and base are separated and 2) the chemical constituents rotate freely. The physical state of these proton-conducting salts can be liquid, plastic crystal as well as solid organic and inorganic polymer membranes and their mixtures. Many acids and bases can be used to make a protic salt which allows tailoring of proton conductivity, as well as other properties that affect their use as electrolytes in fuel cells, such as, stability, adsorption on catalysts, environmental impact, etc. During this project, highly proton conducting (~ 0.1S/cm) protic salts were made that are stable under fuel-cell operating conditions and that gave highly efficient fuel cells. The high efficiency is attributed to an improved oxygen electroreduction process on Pt which was found to be virtually reversible in a number of liquid protic salts with low water activity (< 1% water). Solid flexible non-porous composite membranes, made from inorganic polymer (e.g., 10%indium 90%tin pyrophosphate, ITP) and organic polymer (e.g., polyvinyl pyridinium phosphate, PVPP), were found that give conductivity and fuel cell performances similar to phosphoric acid electrolyte with no need for hydration at

  17. IONIC CONDUCTIVITY AND ELECTRICAL PROPERTIES OF CARBOXYMETHYL CELLULOSE - NH4Cl SOLID POLYMER ELECTROLYTES

    Directory of Open Access Journals (Sweden)

    N. H. AHMAD

    2016-06-01

    Full Text Available In this present work, carboxymethyl cellulose (CMC – ammonium chloride (NH4Cl solid polymer electrolyte (SPE films were prepared by solution casting method. The ionic conductivity and electrical properties of SPE films were investigated using Electrical Impedance Spectroscopy. SPE film containing 16 wt. % NH4Cl exhibited the highest ionic conductivity of 1.43 x 10-3 S/cm at ambient temperature, 303K. The temperature dependence SPE films showed an Arrhenius-type relation where the regression values obtained from the log conductivity versus reciprocal temperature is close to unity (R2≈1. The electrical properties have been measured as a function of frequency of Ԑr,Ԑi, Mr, Mi shown a non-Debye type behavior

  18. Carbon Nanotube/Conductive Additive/Space Durable Polymer Nanocomposite Films for Electrostatic Charge Dissipation

    Science.gov (United States)

    Smith, Joseph G., Jr.; Watson, Kent A.; Delozier, Donavon M.; Connell, John W.

    2003-01-01

    Thin film membranes of space environmentally stable polymeric materials possessing low color/solar absorptivity (alpha) are of interest for potential applications on Gossamer spacecraft. In addition to these properties, sufficient electrical conductivity is required in order to dissipate electrostatic charge (ESC) build-up brought about by the charged orbital environment. One approach to achieve sufficient electrical conductivity for ESC mitigation is the incorporation of single wall carbon nanotubes (SWNTs). However, when the SWNTs are dispersed throughout the polymer matrix, the nanocomposite films tend to be significantly darker than the pristine material resulting in a higher alpha. The incorporation of conductive additives in combination with a decreased loading level of SWNTs is one approach for improving alpha while retaining conductivity. Taken individually, the low loading level of conductive additives and SWNTs is insufficient in achieving the percolation level necessary for electrical conductivity. When added simultaneously to the film, conductivity is achieved through a synergistic effect. The chemistry, physical, and mechanical properties of the nanocomposite films will be presented.

  19. Quantitative Conductive Atomic Force Microscopy on Single-Walled Carbon Nanotube-Based Polymer Composites.

    Science.gov (United States)

    Bârsan, Oana A; Hoffmann, Günter G; van der Ven, Leendert G J; de With, Gijsbertus

    2016-08-01

    Conductive atomic force microscopy (C-AFM) is a valuable technique for correlating the electrical properties of a material with its topographic features and for identifying and characterizing conductive pathways in polymer composites. However, aspects such as compatibility between tip material and sample, contact force and area between the tip and the sample, tip degradation and environmental conditions render quantifying the results quite challenging. This study aims at finding the suitable conditions for C-AFM to generate reliable, reproducible, and quantitative current maps that can be used to calculate the resistance in each point of a single-walled carbon nanotube (SWCNT) network, nonimpregnated as well as impregnated with a polymer. The results obtained emphasize the technique's limitation at the macroscale as the resistance of these highly conductive samples cannot be distinguished from the tip-sample contact resistance. Quantitative C-AFM measurements on thin composite sections of 150-350 nm enable the separation of sample and tip-sample contact resistance, but also indicate that these sections are not representative for the overall SWCNT network. Nevertheless, the technique was successfully used to characterize the local electrical properties of the composite material, such as sample homogeneity and resistance range of individual SWCNT clusters, at the nano- and microscale. PMID:27404764

  20. Free-Standing Conducting Polymer Films for High-Performance Energy Devices.

    Science.gov (United States)

    Li, Zaifang; Ma, Guoqiang; Ge, Ru; Qin, Fei; Dong, Xinyun; Meng, Wei; Liu, Tiefeng; Tong, Jinhui; Jiang, Fangyuan; Zhou, Yifeng; Li, Ke; Min, Xue; Huo, Kaifu; Zhou, Yinhua

    2016-01-18

    Thick, uniform, easily processed, highly conductive polymer films are desirable as electrodes for solar cells as well as polymer capacitors. Here, a novel scalable strategy is developed to prepare highly conductive thick poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (HCT-PEDOT:PSS) films with layered structure that display a conductivity of 1400 S cm(-1) and a low sheet resistance of 0.59 ohm sq(-1). Organic solar cells with laminated HCT-PEDOT:PSS exhibit a performance comparable to the reference devices with vacuum-deposited Ag top electrodes. More importantly, the HCT-PEDOT:PSS film delivers a specific capacitance of 120 F g(-1) at a current density of 0.4 A g(-1). All-solid-state flexible symmetric supercapacitors with the HCT-PEDOT:PSS films display a high volumetric energy density of 6.80 mWh cm(-3) at a power density of 100 mW cm(-3) and 3.15 mWh cm(-3) at a very high power density of 16160 mW cm(-3) that outperforms previous reported solid-state supercapacitors based on PEDOT materials. PMID:26630234

  1. Application of conductive polymers, scaffolds and electrical stimulation for nerve tissue engineering.

    Science.gov (United States)

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein; Kiani, Sahar; Al-Deyab, Salem S; Ramakrishna, Seeram

    2011-04-01

    Among the numerous attempts to integrate tissue engineering concepts into strategies to repair nearly all parts of the body, neuronal repair stands out. This is partially due to the complexity of the nervous anatomical system, its functioning and the inefficiency of conventional repair approaches, which are based on single components of either biomaterials or cells alone. Electrical stimulation has been shown to enhance the nerve regeneration process and this consequently makes the use of electrically conductive polymers very attractive for the construction of scaffolds for nerve tissue engineering. In this review, by taking into consideration the electrical properties of nerve cells and the effect of electrical stimulation on nerve cells, we discuss the most commonly utilized conductive polymers, polypyrrole (PPy) and polyaniline (PANI), along with their design and modifications, thus making them suitable scaffolds for nerve tissue engineering. Other electrospun, composite, conductive scaffolds, such as PANI/gelatin and PPy/poly(ε-caprolactone), with or without electrical stimulation, are also discussed. Different procedures of electrical stimulation which have been used in tissue engineering, with examples on their specific applications in tissue engineering, are also discussed.

  2. Copper selenide nanocrystals for photothermal therapy.

    Science.gov (United States)

    Hessel, Colin M; Pattani, Varun P; Rasch, Michael; Panthani, Matthew G; Koo, Bonil; Tunnell, James W; Korgel, Brian A

    2011-06-01

    Ligand-stabilized copper selenide (Cu(2-x)Se) nanocrystals, approximately 16 nm in diameter, were synthesized by a colloidal hot injection method and coated with amphiphilic polymer. The nanocrystals readily disperse in water and exhibit strong near-infrared (NIR) optical absorption with a high molar extinction coefficient of 7.7 × 10(7) cm(-1) M(-1) at 980 nm. When excited with 800 nm light, the Cu(2-x)Se nanocrystals produce significant photothermal heating with a photothermal transduction efficiency of 22%, comparable to nanorods and nanoshells of gold (Au). In vitro photothermal heating of Cu(2-x)Se nanocrystals in the presence of human colorectal cancer cell (HCT-116) led to cell destruction after 5 min of laser irradiation at 33 W/cm(2), demonstrating the viabilitiy of Cu(2-x)Se nanocrystals for photothermal therapy applications. PMID:21553924

  3. Enhanced Flexible Tubular Microelectrode with Conducting Polymer for Multi-Functional Implantable Tissue-Machine Interface

    Science.gov (United States)

    Tian, Hong-Chang; Liu, Jing-Quan; Kang, Xiao-Yang; Tang, Long-Jun; Wang, Ming-Hao; Ji, Bo-Wen; Yang, Bin; Wang, Xiao-Lin; Chen, Xiang; Yang, Chun-Sheng

    2016-05-01

    Implantable biomedical microdevices enable the restoration of body function and improvement of health condition. As the interface between artificial machines and natural tissue, various kinds of microelectrodes with high density and tiny size were developed to undertake precise and complex medical tasks through electrical stimulation and electrophysiological recording. However, if only the electrical interaction existed between electrodes and muscle or nerve tissue without nutrition factor delivery, it would eventually lead to a significant symptom of denervation-induced skeletal muscle atrophy. In this paper, we developed a novel flexible tubular microelectrode integrated with fluidic drug delivery channel for dynamic tissue implant. First, the whole microelectrode was made of biocompatible polymers, which could avoid the drawbacks of the stiff microelectrodes that are easy to be broken and damage tissue. Moreover, the microelectrode sites were circumferentially distributed on the surface of polymer microtube in three dimensions, which would be beneficial to the spatial selectivity. Finally, the in vivo results confirmed that our implantable tubular microelectrodes were suitable for dynamic electrophysiological recording and simultaneous fluidic drug delivery, and the electrode performance was further enhanced by the conducting polymer modification.

  4. Development of ammonia sensors by using conductive polymer/hydroxyapatite composite materials.

    Science.gov (United States)

    Huixia, Li; Yong, Liu; Lanlan, Luo; Yanni, Tan; Qing, Zhang; Kun, Li

    2016-02-01

    In order to improve the gas sensing properties, hydroxyapatite (HAp)-based composites were prepared by mixing with different contents of conductive polymers: polypyrrole (PPy) and polyaniline (PAni). The compositions, microstructures and phase constitutions of polymer/HAp composites were characterized, and the sensing properties were studied using a chemical gas sensing (CGS-8) system. The results showed that, compared to pure HAp, the sensitivities of the composites to ammonia were improved significantly. 5%PPy/HAp and 20%PAni/HAp composites exhibited the best sensitivities to ammonia, and the sensitivities at 500ppm were 86.72% and 86.18%, respectively. Besides, the sensitivity of 5%PPy/HAp at 1000ppm was up to 90.7%. Compared to pure PPy and PAni, the response and the recovery time of 5%PPy/HAp and 20%PAni/HAp at 200ppm were shortened several times, and they were 24s/245s and 15s/54s, respectively. In addition, the composites showed a very high selectivity to ammonia. The mechanism for the enhancement of the sensitivity to ammonia was also discussed. The polymer/HAp composites are very promising in applications of ammonia sensors.

  5. Electrical Conductivity Studies on Individual Conjugated Polymer Nanowires: Two-Probe and Four-Probe Results

    Directory of Open Access Journals (Sweden)

    Duvail JeanLuc

    2009-01-01

    Full Text Available Abstract Two- and four-probe electrical measurements on individual conjugated polymer nanowires with different diameters ranging from 20 to 190 nm have been performed to study their conductivity and nanocontact resistance. The two-probe results reveal that all the measured polymer nanowires with different diameters are semiconducting. However, the four-probe results show that the measured polymer nanowires with diameters of 190, 95–100, 35–40 and 20–25 nm are lying in the insulating, critical, metallic and insulting regimes of metal–insulator transition, respectively. The 35–40 nm nanowire displays a metal–insulator transition at around 35 K. In addition, it was found that the nanocontact resistance is in the magnitude of 104Ω at room temperature, which is comparable to the intrinsic resistance of the nanowires. These results demonstrate that four-probe electrical measurement is necessary to explore the intrinsic electronic transport properties of isolated nanowires, especially in the case of metallic nanowires, because the metallic nature of the measured nanowires may be coved by the nanocontact resistance that cannot be excluded by a two-probe technique.

  6. Surface plasmon resonance sensing detection of mercury and lead ions based on conducting polymer composite.

    Directory of Open Access Journals (Sweden)

    Mahnaz M Abdi

    Full Text Available A new sensing area for a sensor based on surface plasmon resonance (SPR was fabricated to detect trace amounts of mercury and lead ions. The gold surface used for SPR measurements were modified with polypyrrole-chitosan (PPy-CHI conducting polymer composite. The polymer layer was deposited on the gold surface by electrodeposition. This optical sensor was used for monitoring toxic metal ions with and without sensitivity enhancement by chitosan in water samples. The higher amounts of resonance angle unit (ΔRU were obtained for PPy-CHI film due to a specific binding of chitosan with Pb(2+ and Hg(2+ ions. The Pb(2+ ion bind to the polymer films most strongly, and the sensor was more sensitive to Pb(2+ compared to Hg(2+. The concentrations of ions in the parts per million range produced the changes in the SPR angle minimum in the region of 0.03 to 0.07. Data analysis was done by Matlab software using Fresnel formula for multilayer system.

  7. 2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion

    Science.gov (United States)

    Kang, Keehoon; Watanabe, Shun; Broch, Katharina; Sepe, Alessandro; Brown, Adam; Nasrallah, Iyad; Nikolka, Mark; Fei, Zhuping; Heeney, Martin; Matsumoto, Daisuke; Marumoto, Kazuhiro; Tanaka, Hisaaki; Kuroda, Shin-Ichi; Sirringhaus, Henning

    2016-08-01

    Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility.

  8. Enhancing the Thermal Conductance of Polymer and Sapphire Interface via Self-Assembled Monolayer.

    Science.gov (United States)

    Zheng, Kun; Sun, Fangyuan; Zhu, Jie; Ma, Yongmei; Li, Xiaobo; Tang, Dawei; Wang, Fosong; Wang, Xiaojia

    2016-08-23

    Interfacial thermal conductance (ITC) receives enormous consideration because of its significance in determining thermal performance of hybrid materials, such as polymer based nanocomposites. In this study, the ITC between sapphire and polystyrene (PS) was systematically investigated by time domain thermoreflectance (TDTR) method. Silane based self-assembled monolayers (SAMs) with varying end groups, -NH2, -Cl, -SH and -H, were introduced into sapphire/PS interface, and their effects on ITC were investigated. The ITC was found to be enhanced up by a factor of 7 through functionalizing the sapphire surface with SAM, which ends with a chloride group (-Cl). The results show that the enhancement of the thermal transport across the SAM-functionalized interface comes from both strong covalent bonding between sapphire and silane-based SAM, and the high compatibility between the SAM and PS. Among the SAMs studied in this work, we found that the ITC almost linearly depends on solubility parameters, which could be the dominant factor influencing on the ITC compared with wettability and adhesion. The SAMs serve as an intermediate layer that bridges the sapphire and PS. Such a feature can be applied to ceramic-polymer immiscible interfaces by functionalizing the ceramic surface with molecules that are miscible with the polymer materials. This research provides guidance on the design of critical-heat transfer materials such as composites and nanofluids for thermal management. PMID:27501117

  9. Field Emission Characteristics of Conducting Polymer Films Conditioned by Electric Discharge

    Institute of Scientific and Technical Information of China (English)

    Guohong LAI; Zhenglin LI; Lan CHENG; Junbiao PENG

    2006-01-01

    A pure conducting polymer(PANI-CSA)film conditioned by an electric discharge was tentatively utilized as an cathode for emitting electrons under electric fields. The emission of electrons was observed using a phosphor(ZnO:Zn)screen excited by electrons from the conditioned film. The film morphology was investigated using a scanning electron microscope and it was found that undulate whisker-like sites formed on the surface. The emission was presumably due to the undulate whisker-like sites. The field enhancement factor was estimated to be as high as 1150. The electron emitting process of the PANI-CSA film conditioned by electric discharge was also discussed.

  10. Conducting polymers based counter electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Veerender, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Saxena, Vibha, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gusain, Abhay, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Jha, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Koiry, S. P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Chauhan, A. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Aswal, D. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gupta, S. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai - 400085 (India)

    2014-04-24

    Conducting polymer films were synthesized and employed as an alternative to expensive platinum counter electrodes for dye-sensitized solar cells. poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) thin films were spin-coated and polypyrrole films were electrochemically deposited via cyclic voltammetry method on ITO substrates. The morphology of the films were imaged by SEM and AFM. These films show good catalytic activity towards triiodide reduction as compared to Pt/FTO electrodes. Finally the photovoltaic performance of DSSC fabricated using N3 dye were compared with PT/FTO, PEDOT/ITO, and e-PPy counter electrodes.

  11. Electrically tunable liquid-crystal wave plate using quadripolar electrode configuration and transparent conductive polymer layers.

    Science.gov (United States)

    Fraval, Nicolas; Joffre, Pascal; Formont, Stéphane; Chazelas, Jean

    2009-10-01

    We present the realization of an electrically tunable wave plate, which uses a nematic liquid-crystal (LC) phase retarder that allows fast and continuous control of the polarization state. This device is built using a quadripolar electrode design and transparent conductive polymer layers in order to obtain a uniform electric field distribution in the interelectrode area. With this realization, we obtain a high degree of control of the orientation of the electric field and, consequently, of the LC director. Indeed, this modulator outperforms classical bipolar LC cells in both optical path variation (>4 microm) and LC rotation speed (0.4 degrees/micros). PMID:19798369

  12. A summary report on the Flat-Plate Solar Array Project Workshop on Transparent Conducting Polymers

    Science.gov (United States)

    Kachare, R.; Moacanin, J.

    1985-01-01

    The proceedings and technical discussions of a workshop on Transparent Conducting Polymers (TCP) for solar cell applications are reported. This is in support of the Device Research Task of the Flat-Flate Solar Array Project. The workshop took place on January 11 and 12, 1985, in Santa Barbara, California. Participants included university and industry researchers. The discussions focused on the electronic and optical properties of TCP, and on experimental issues and problems that should be addressed for high-efficiency solar cell application.

  13. Morphology and conductivity of in-situ PEO-LiClO4-TiO2 composite polymer electrolyte

    Institute of Scientific and Technical Information of China (English)

    PAN Chun-yue; FENG Qing; WANG Li-jun; ZHANG Qian; CHAO Meng

    2007-01-01

    PEO-LiClO4-TiO2 composite polymer electrolyte films were prepared. TiO2 was formed directly in matrix by hydrolysis and condensation reaction of tetrabutyl titanate. The crystallinity, morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry, scanning electron microscopy, atom force microscopy and alternating current impedance spectroscopy, respectively. The glass transition temperature and the crystallinity of composite polymer electrolytes are decreased compared with those of PEO-LiClO4 polymer electrolyte film. The results show that TiO2 particles are uniformly dispersed in PEO-LiClO4-5%TiO2 composite polymer electrolyte film. The maximal conductivity of 5.5×10-5 S/cm at 20 ℃ of PEO-LiClO4-TiO2 film is obtained at 5% mass fraction of TiO2.

  14. Investigation of the Ionic conductivity and dielectric measurements of poly (N-vinyl pyrrolidone)-sulfamic acid polymer complexes

    International Nuclear Information System (INIS)

    Polymer electrolyte complexes of poly (N-vinyl pyrrolidone) (PVP)-sulfamic acid (NH2SO3H) were prepared by a familiar solution casting method with different molar concentrations of PVP and sulfamic acid. The interaction between PVP and NH2SO3H was confirmed by Fourier transform infrared spectroscopy analysis. Laser microscopy analysis was used to study the surface morphology of the polymer complexes. The glass transition temperature (Tg) and the melting temperature (Tm) of polymer complexes were computed from Differential scanning calorimetric studies. AC impedance spectroscopic measurements revealed that the polymer complex, 97 mol% PVP-3 mol% NH2SO3H shows higher ionic conductivity with two different activation energies above and below the glass transition temperature (Tg). Dielectric studies confirmed that the dc conduction mechanism has dominated in the polymer complexes. The value of power law exponent (n) confirmed the translational motion of ions from one site to another vacant site in these complexes

  15. Glycosylated Conductive Polymer: A Multimodal Biointerface for Studying Carbohydrate-Protein Interactions.

    Science.gov (United States)

    Zeng, Xiangqun; Qu, Ke; Rehman, Abdul

    2016-09-20

    Carbohydrate-protein interactions occur through glycoproteins, glycolipids, or polysaccharides displayed on the cell surface with lectins. However, studying these interactions is challenging because of the complexity and heterogeneity of the cell surface, the inherent structural complexity of carbohydrates, and the typically weak affinities of the binding reactions between the lectins and monovalent carbohydrates. The lack of chromophores and fluorophores in carbohydrate structures often drives such investigations toward fluorescence labeling techniques, which usually require tedious and complex synthetic work to conjugate fluorescent tags with additional risk of altering the reaction dynamics. Probing these interactions directly on the cell surface is even more difficult since cells could be too fragile for labeling or labile dynamics could be affected by the labeled molecules that may interfere with the cellular activities, resulting in unwanted cell responses. In contrast, label-free biosensors allow real-time monitoring of carbohydrate-protein interactions in their natural states. A prerequisite, though, for this strategy to work is to mimic the coding information on potential interactions of cell surfaces onto different biosensing platforms, while the complementary binding process can be transduced into a useful signal noninvasively. Through carbohydrate self-assembled monolayers and glycopolymer scaffolds, the multivalency of the naturally existing simple and complex carbohydrates can be mimicked and exploited with label-free readouts (e.g., optical, acoustic, mechanical, electrochemical, and electrical sensors), yet such inquiries reflect only limited aspects of complicated biointeraction processes due to the unimodal transduction. In this Account, we illustrate that functionalized glycosylated conductive polymer scaffolds are the ideal multimodal biointerfaces that not only simplify the immobilization process for surface fabrication via electrochemical

  16. Conductivity type and crystal orientation of GaAs nanocrystals fabricated in silicon by ion implantation and flash lamp annealing

    International Nuclear Information System (INIS)

    The integration of III–V semiconductor material within silicon technology is crucial for performance of advanced electronic devices. This paper presents the investigations of microstructural and opto-electronic properties of GaAs quantum dots (QDs) formed in silicon by means of sequential ion implantation and flash lamp annealing (FLA). Formation of crystalline GaAs QDs with well-defined crystal orientation and conductivity type was confirmed by high resolution transmission electron microscopy and μ-Raman spectroscopy. The influence of the post implantation millisecond-range annealing on the evolution of the nanoparticles size, shape, crystallographic orientation and doping type of GaAs QDs is discussed

  17. Selenium containing conducting polymer based pyranose oxidase biosensor for glucose detection.

    Science.gov (United States)

    Gokoglan, Tugba Ceren; Soylemez, Saniye; Kesik, Melis; Toksabay, Sinem; Toppare, Levent

    2015-04-01

    A novel amperometric pyranose oxidase (PyOx) biosensor based on a selenium containing conducting polymer has been developed for the glucose detection. For this purpose, a conducting polymer; poly(4,7-bis(thieno[3,2-b]thiophen-2-yl)benzo[c][1,2,5] selenadiazole) (poly(BSeTT)) was synthesized via electropolymerisation on gold electrode to examine its matrix property for glucose detection. For this purpose, PyOx was used as the model enzyme and immobilised via physical adsorption technique. Amperometric detection of consumed oxygen was monitored at -0.7 V vs Ag reference electrode in a phosphate buffer (50 mM, pH 7.0). K(M)(app), Imax, LOD and sensitivity were calculated as 0.229 mM, 42.37 nA, 3.3 × 10(-4)nM and 6.4 nA/mM cm(2), respectively. Scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS) and cyclic voltammetry (CV) techniques were used to monitor changes in surface morphologies and to run electrochemical characterisations. Finally, the constructed biosensor was applied for the determination of glucose in beverages successfully. PMID:25442546

  18. OPTIMIZED DESIGN OF BIO-SENSOR USING CONDUCTING POLYMERS AND NANOCOMPOSITES

    Directory of Open Access Journals (Sweden)

    Usha.A,

    2011-04-01

    Full Text Available This Research work is focused on the design, development and technological evolution of emerging fields of Nanotechnology and Conducting Polymer Electronics, Bio-Tech based Embedded Sensors and Smart Systems employing System-0n- Chip (SOC Core, as applied to Health Monitoring of Human and Complex Systems in Engineering and Medicine. With the Invention of Thin-Film Technology, it is now possible to fabricate Novel Conducting-Polymer based sensors and devices with built-in-flexible electronics resulting in high throughput devices and systems that are flexible, lighter, bio-compatible and economical also. The flexible and EmbeddedElectronics is a key enabler for a number of platform methodologies such as Designed Thin-Films, Smart Electronics and Sensor Devices. The integration of the Bio-Sensor with embedded electronics data conditioning and processing SOC and Wireless –Communication System may provide vast opportunities for Biological – Sensor Applications, especially for physiological monitoring of Leukocyte-Counts in blood sample or analyte for Leukemia Patients in the Society.

  19. Effects of carbon nanotube and conducting polymer coated microelectrodes on single-unit recordings in vitro.

    Science.gov (United States)

    Charkhkar, Hamid; Knaack, Gretchen L; Mandal, Himadri S; Keefer, Edward W; Pancrazio, Joseph J

    2014-01-01

    Neuronal networks cultured on microelectrode arrays (MEAs) have been utilized as biosensors that can detect all or nothing extracellular action potentials, or spikes. Coating the microelectrodes with carbon nanotubes (CNTs), either pristine or conjugated with a conductive polymer, has been previously reported to improve extracellular recordings presumably via reduction in microelectrode impedance. The goal of this work was to examine the basis of such improvement in vitro. Every other microelectrode of in vitro MEAs was electrochemically modified with either conducting polymer, poly-3,4-ethylenedioxythiophene (PEDOT) or a blend of CNT and PEDOT. Mouse cortical tissue was dissociated and cultured on the MEAs to form functional neuronal networks. The performance of the modified and unmodified microelectrodes was evaluated by activity measures such as spike rate, spike amplitude, burst duration and burst rate. We observed that the yield, defined as percentage of microelectrodes with neuronal activity, was significantly higher by 55% for modified microelectrodes compared to the unmodified sites. However, the spike rate and burst parameters were similar for modified and unmodified microelectrodes suggesting that neuronal networks were not physiologically altered by presence of PEDOT or PEDOT-CNT. Our observations from immunocytochemistry indicated that neuronal cells were more abundant in proximity to modified microelectrodes. PMID:25569998

  20. Synthesis and Ionic Conductivity of Siloxane Based Polymer Electrolytes with Propyl Butyrate Pendant Groups

    Energy Technology Data Exchange (ETDEWEB)

    Jalagonia, Natia; Tatrishvili, Tamara; Markarashvili, Eliza; Aneli, Jimsher; Mukbaniani, Omar [Javakhishvili Tbilisi State University, Tbilisi (Georgia); Grazulevicius, Jouzas Vidas [Kaunas University of Technology, Kaunas (Lithuania)

    2016-02-15

    Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, H2PtCl6 and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of CaF2, LiF, KF and anhydrous potassium hydroxide in 60-70 .deg. C temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range 3.5x10{sup -4} - 6.4xa0{sup -7} S/cm.

  1. Freeze Drying Improves the Shelf-Life of Conductive Polymer Modified Neural Electrodes

    Directory of Open Access Journals (Sweden)

    Himadri S. Mandal

    2015-08-01

    Full Text Available Coating microelectrodes with conductive polymer is widely recognized to decrease impedance and improve performance of implantable neural devices during recording and stimulation. A concern for wide-spread use of this approach is shelf-life, i.e., the electrochemical stability of the coated microelectrodes prior to use. In this work, we investigated the possibility of using the freeze-drying process in order to retain the native low impedance state and, thereby, improve the shelf-life of conductive polymer poly(3,4-ethylenedioxythiophene (PEDOT-PSS modified neural electrodes. Control PEDOT-PSS coated microelectrodes demonstrated a significant increase in impedance at 1 kHz after 41–50 days of room temperature storage. Based on equivalent circuit modeling derived from electrochemical impedance spectroscopy, this increase in impedance could be largely attributed to a decrease in the interfacial capacitance consistent with a collapse and closing of the porous structure of the polymeric coating. Time-dependent electrochemical impedance measurements revealed higher stability of the freeze-dried coated microelectrodes compared to the controls, such that impedance values after 41–50 days appeared to be indistinguishable from the initial levels. This suggests that freeze drying PEDOT-PSS coated microelectrodes correlates with enhanced electrochemical stability during shelf storage.

  2. Highly stable supercapacitors with conducting polymer core-shell electrodes for energy storage applications

    KAUST Repository

    Xia, Chuan

    2015-01-14

    Conducting polymers such as polyaniline (PAni) show a great potential as pseudocapacitor materials for electrochemical energy storage applications. Yet, the cycling instability of PAni resulting from structural alteration is a major hurdle to its commercial application. Here, the development of nanostructured PAni-RuO2 core-shell arrays as electrodes for highly stable pseudocapacitors with excellent energy storage performance is reported. A thin layer of RuO2 grown by atomic layer deposition (ALD) on PAni nanofibers plays a crucial role in stabilizing the PAni pseudocapacitors and improving their energy density. The pseudocapacitors, which are based on optimized PAni-RuO2 core-shell nanostructured electrodes, exhibit very high specific capacitance (710 F g-1 at 5 mV s-1) and power density (42.2 kW kg-1) at an energy density of 10 Wh kg-1. Furthermore, they exhibit remarkable capacitance retention of ≈88% after 10 000 cycles at very high current density of 20 A g-1, superior to that of pristine PAni-based pseudocapacitors. This prominently enhanced electrochemical stability successfully demonstrates the buffering effect of ALD coating on PAni, which provides a new approach for the preparation of metal-oxide/conducting polymer hybrid electrodes with excellent electrochemical performance.

  3. Electrical conductivity and luminescence properties of two silver(I) coordination polymers with heterocyclic nitrogen ligands

    International Nuclear Information System (INIS)

    The synthesis and X-ray structural characterization of two novel silver(I) coordination polymers, [Ag(NO3)(quin)]n (1) and [Ag8(HL)2(H2O)4(mpyz)]·3H2O (2) are reported, where quin=5,6,7,8-tetrahydroquinoxaline, H6L=cyclohexane-1,2,3,4,5,6-hexacarboxylic acid and mpyz=2-methyl pyrazine. The single crystal diffraction analyses showed that complex 1 is a 2D layered structure, while 2 presents a 3D polymeric architecture. In complex 2 the network is stabilized by argentophilic interactions and hydrogen bonding. Electrical conductivity of order 3×10−4 Scm−1 (1) and 1.6×10−4 Scm−1 (2) is measured on thin film specimen at room temperature. The photoluminescence and thermal properties of the complexes have also been studied. - Graphical abstract: Two new 1D and 3D coordination polymers of Ag(I) have been synthesized and characterized by X-ray analysis. The electrical, luminescence and thermal properties have been studied. - Highlights: • 1 is 2D layered while 2 present a 3D polymeric architecture. • The network in 2 is stabilized by argentophilic interactions and hydrogen bonding. • Electrical conductivity measurement is quite interesting. • Argentophilic interaction and intra-ligand π⁎–π CT explains emission behavior of 2

  4. Conductive Polymer-Coated VS4 Submicrospheres As Advanced Electrode Materials in Lithium-Ion Batteries.

    Science.gov (United States)

    Zhou, Yanli; Li, Yanlu; Yang, Jing; Tian, Jian; Xu, Huayun; Yang, Jian; Fan, Weiliu

    2016-07-27

    VS4 as an electrode material in lithium-ion batteries holds intriguing features like high content of sulfur and one-dimensional structure, inspiring the exploration in this field. Herein, VS4 submicrospheres have been synthesized via a simple solvothermal reaction. However, they quickly degrade upon cycling as an anode material in lithium-ion batteries. So, three conductive polymers, polythiophene (PEDOT), polypyrrole (PPY), and polyaniline (PANI), are coated on the surface to improve the electron conductivity, suppress the diffusion of polysulfides, and modify the interface between electrode/electrolyte. PANI is the best in the polymers. It improves the Coulombic efficiency to 86% for the first cycle and keeps the specific capacity at 755 mAh g(-1) after 50 cycles, higher than the cases of naked VS4 (100 mAh g(-1)), VS4@PEDOT (318 mAh g(-1)), and VS4@PPY (448 mAh g(-1)). The good performances could be attributed to the improved charge-transfer kinetics and the strong interaction between PANI and VS4 supported by theoretical simulation. The discharge voltage ∼2.0 V makes them promising cathode materials. PMID:27377263

  5. Interfacial polymerization of conductive polymers: Generation of polymeric nanostructures in a 2-D space.

    Science.gov (United States)

    Dallas, Panagiotis; Georgakilas, Vasilios

    2015-10-01

    In the recent advances in the field of conductive polymers, the fibrillar or needle shaped nanostructures of polyaniline and polypyrrole have attracted significant attention due to the potential advantages of organic conductors that exhibit low-dimensionality, uniform size distribution, high crystallinity and improved physical properties compared to their bulk or spherically shaped counterparts. Carrying the polymerization reaction in a restricted two dimensional space, instead of the three dimensional space of the one phase solution is an efficient method for the synthesis of polymeric nanostructures with narrow size distribution and small diameter. Ultra-thin nanowires and nanofibers, single crystal nanoneedles, nanocomposites with noble metals or carbon nanotubes and layered materials can be efficiently synthesized with high yield and display superior performance in sensors and energy storage applications. In this critical review we will focus not only on the interfacial polymerization methods that leads to polymeric nanostructures and composites and their properties, but also on the mechanism and the physico-chemical processes that govern the diffusion and reactivity of molecules and nanomaterials at an interface. Recent advances for the synthesis of conductive polymer composites with an interfacial method for energy storage applications and future perspectives are presented.

  6. The effects of hyperbranched poly(siloxysilane)s on conductive polymer aluminum solid electrolytic capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Nogami, Katsunori [Graduate School of Tokyo Institute Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Nippon Chemi-Con Co., 185-1, Marunouchi, Yabuki-machi, Nishi-Shirakawa-gun, Fukushima 969-0235 (Japan); Sakamoto, Kiyoshi [Nippon Chemi-Con Co., 185-1, Marunouchi, Yabuki-machi, Nishi-Shirakawa-gun, Fukushima 969-0235 (Japan); Hayakawa, Teruaki; Kakimoto, Masa-aki [Graduate School of Tokyo Institute Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2007-04-15

    An aluminum solid electrolytic capacitor, using poly-(3,4-ethylenedioxythiophene) (PEDOT) as a counter electrode, was prepared with hyperbranched poly(siloxysilane)s (HBPSi) that has a large number of vinyl groups to improve the interfacial properties between aluminum oxide and PEDOT. Capacitance and equivalent series resistance (Rs) were significantly improved compared to untreated oxide film and vinyl terminated polydimethylsiloxane coated interfaces. From electrochemical measurement of the withstand voltage, damage to the oxide film from chemical polymerization of PEDOT was less with the HBPSi treatment. Frequency characteristics and electrical conductivity measurements of the polymer indicated that the resistance inside the etched porous layer was greatly reduced. These results show that the HBPSi pre-coating layer inhibited degradation of the oxide film by chemical polymerization of PEDOT and the conductivity of PEDOT in the etched porous oxide layer, and also enlarges the contact area by improving interfacial adhesion. (author)

  7. LITHIUM ION CONDUCTING POLYMER ELECTROLYTES BASED ON ALTERNATING MALEIC ANHYDRIDE COPOLYMER WITH OLIGO-OXYETHYLENE SIDE CHAINS

    Institute of Scientific and Technical Information of China (English)

    DING Liming

    1996-01-01

    A comb polymer with oligo-oxyethylene side chains of the type -(CH2CH2O)12CH3 was prepared from methyl vinyl ether/maleic anhydride copolymer and poly (ethylene glycol) methyl ether. The polymer can dissolve LiClO4 salt to form homogeneous amorphous polymer electrolyte. The ac ion conduction was measured using the complex impedance method, and conductivities were investigated as functions of temperatures and salt concentration. The complexes were first found to have two classes of glass transition which increase with increasing salt content. The optimum conductivity attained at 25℃ is in the order of 5.50 × 10-6Scm-1. IR spectroscopy was used to study the cation-polymer interaction.

  8. Ice-Templated Assembly Strategy to Construct 3D Boron Nitride Nanosheet Networks in Polymer Composites for Thermal Conductivity Improvement.

    Science.gov (United States)

    Zeng, Xiaoliang; Yao, Yimin; Gong, Zhengyu; Wang, Fangfang; Sun, Rong; Xu, Jianbin; Wong, Ching-Ping

    2015-12-01

    Owing to the growing heat removal issue of modern electronic devices, polymer composites with high thermal conductivity have drawn much attention in the past few years. However, a traditional method to enhance the thermal conductivity of the polymers by addition of inorganic fillers usually creates composite with not only limited thermal conductivity but also other detrimental effects due to large amount of fillers required. Here, novel polymer composites are reported by first constructing 3D boron nitride nanosheets (3D-BNNS) network using ice-templated approach and then infiltrating them with epoxy matrix. The obtained polymer composites exhibit a high thermal conductivity (2.85 W m(-1) K(-1)), a low thermal expansion coefficient (24-32 ppm K(-1)), and an increased glass transition temperature (T(g)) at relatively low BNNSs loading (9.29 vol%). These results demonstrate that this approach opens a new avenue for design and preparation of polymer composites with high thermal conductivity. The polymer composites are potentially useful in advanced electronic packaging techniques, namely, thermal interface materials, underfill materials, molding compounds, and organic substrates.

  9. Ice-Templated Assembly Strategy to Construct 3D Boron Nitride Nanosheet Networks in Polymer Composites for Thermal Conductivity Improvement.

    Science.gov (United States)

    Zeng, Xiaoliang; Yao, Yimin; Gong, Zhengyu; Wang, Fangfang; Sun, Rong; Xu, Jianbin; Wong, Ching-Ping

    2015-12-01

    Owing to the growing heat removal issue of modern electronic devices, polymer composites with high thermal conductivity have drawn much attention in the past few years. However, a traditional method to enhance the thermal conductivity of the polymers by addition of inorganic fillers usually creates composite with not only limited thermal conductivity but also other detrimental effects due to large amount of fillers required. Here, novel polymer composites are reported by first constructing 3D boron nitride nanosheets (3D-BNNS) network using ice-templated approach and then infiltrating them with epoxy matrix. The obtained polymer composites exhibit a high thermal conductivity (2.85 W m(-1) K(-1)), a low thermal expansion coefficient (24-32 ppm K(-1)), and an increased glass transition temperature (T(g)) at relatively low BNNSs loading (9.29 vol%). These results demonstrate that this approach opens a new avenue for design and preparation of polymer composites with high thermal conductivity. The polymer composites are potentially useful in advanced electronic packaging techniques, namely, thermal interface materials, underfill materials, molding compounds, and organic substrates. PMID:26479262

  10. Self-assembled hybrid materials based on conjugated polymers and semiconductors nano-crystals for plastic solar cells; Architectures hybrides auto-assemblees a base de systemes polyconjugues et de nanocristaux de semi-conducteurs pour le photovoltaique plastique

    Energy Technology Data Exchange (ETDEWEB)

    Girolamo, J. de

    2007-11-15

    This work is devoted to the elaboration of self-assembled hybrid materials based on poly(3- hexyl-thiophene) and CdSe nano-crystals for photovoltaic applications. For that, complementary molecular recognition units were introduced as side chain groups on the polymer and at the nano-crystals' surface. Diamino-pyrimidine groups were introduced by post-functionalization of a precursor copolymer, namely poly(3-hexyl-thiophene-co-3- bromo-hexyl-thiophene) whereas thymine groups were introduced at the nano-crystals' surface by a ligand exchange reaction with 1-(6-mercapto-hexyl)thymine. However, due to their different solubility, the mixing of the two components by solution processes is difficult. A 'one-pot' procedure was developed, but this method led to insoluble aggregates without control of the hybrid composition. To overcome the solubility problem, the layer-by-layer method was used to prepare the films. This method allows a precise control of the deposition process. Experimental parameters were tested in order to evaluate their impact on the resulting film. The films morphology was investigated by microscopy and X-Ray diffraction techniques. These analyses reveal an interpenetrated structure of nano-crystals within the polymer matrix rather than a multilayered structure. Electrochemical and spectro electrochemical studies were performed on the hybrid material deposited by the LBL process. Finally the materials were tested in a solar cell configuration and the I=f(V) curves reveals a clear photovoltaic behaviour. (author)

  11. Structural control of mixed ionic and electronic transport in conducting polymers

    Science.gov (United States)

    Rivnay, Jonathan; Inal, Sahika; Collins, Brian A.; Sessolo, Michele; Stavrinidou, Eleni; Strakosas, Xenofon; Tassone, Christopher; Delongchamp, Dean M.; Malliaras, George G.

    2016-04-01

    Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate), PEDOT:PSS, has been utilized for over two decades as a stable, solution-processable hole conductor. While its hole transport properties have been the subject of intense investigation, recent work has turned to PEDOT:PSS as a mixed ionic/electronic conductor in applications including bioelectronics, energy storage and management, and soft robotics. Conducting polymers can efficiently transport both holes and ions when sufficiently hydrated, however, little is known about the role of morphology on mixed conduction. Here, we show that bulk ionic and electronic mobilities are simultaneously affected by processing-induced changes in nano- and meso-scale structure in PEDOT:PSS films. We quantify domain composition, and find that domain purification on addition of dispersion co-solvents limits ion mobility, even while electronic conductivity improves. We show that an optimal morphology allows for the balanced ionic and electronic transport that is critical for prototypical mixed conductor devices. These findings may pave the way for the rational design of polymeric materials and processing routes to enhance devices reliant on mixed conduction.

  12. Electrical conduction and dielectric relaxation in p-type PVA/CuI polymer composite

    Directory of Open Access Journals (Sweden)

    M.H. Makled

    2013-11-01

    Full Text Available PVA/CuI polymer composite samples have been prepared and subjected to characterizations using FT-IR spectroscopy, DSC analysis, ac spectroscopy and dc conduction. The FT-IR spectral analysis shows remarkable variation of the absorption peak positions whereas DSC illustrates a little decrease of both glass transition temperature, Tg, and crystallization fraction, χ, with increasing CuI concentration. An increase of dc conductivity for PVA/CuI nano composite by increasing CuI concentration is recoded up to 15 wt%, besides it obeys Arhenuis plot with an activation energy in the range 0.54–1.32 eV. The frequency dependence of ac conductivity showed power law with an exponent 0.33 < s < 0.69 which predicts hopping conduction mechanism. The frequency dependence of both dielectric permittivity and dielectric loss obeys Debye dispersion relations in wide range of temperatures and frequency. Significant values of dipole relaxation time obtained which are thermally activated with activation energies in the range 0.33–0.87 eV. A significant value of hopping distance in the range 3.4–1.2 nm is estimated in agreement with the value of Bohr radius of the exciton.

  13. Ac conductance and capacitance of carbon black polymer composites during thermal cycling and isothermal annealing

    Science.gov (United States)

    Jäger, K.-M.; McQueen, D. H.; Vilcáková, J.

    2002-05-01

    The ac electrical properties of acetylene black composites mixed into ethylene butylacrylate copolymer (EBA) and into poly (methyl methacrylate) (PMMA) have been measured in thermal cycling and isothermal annealing experiments. The results show that changes in electrical properties are due to rearrangement of gaps between the carbon black aggregates. This has been concluded using an exponent z that relates the critical frequency ωc denoting the crossover of the conductivity from the dc-plateau to its frequency-dependent part to the dc conductivity, σdc, according to ωc ∝σdcz. Below the melting range of EBA and the glass transition of PMMA z is about one corresponding to strong variation of the conductivity and weak dependence of the permittivity on the gaps. Above the melting range of EBA z is about 1.5, indicating strong dependence of both the conductivity and the permittivity on the gaps, as predicted by percolation theory. This was not found in the PMMA composites above the glass transition. We conclude that the polymer matrix affects the nature of the gaps between carbon black aggregates, either allowing their size to vary continuously (z about 1) or letting them open and close (z about 1.5).

  14. Controlled morphology of conducting polymers: Formation of nanorods and microspheres of polyindole

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Bhavana; Chauhan, Dheeraj Singh [School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Varanasi, UP 221005 (India); Prakash, Rajiv, E-mail: rajivprakash12@yahoo.com [School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Varanasi, UP 221005 (India)

    2010-04-15

    One-dimensional nanotubes and nanowires have attracted attention because of their unique electronic and mechanical properties, resulting in the promising applications in electrical, electronic and nanodevices or three-dimensional hollow spheres because of drug delivery, encapsulations and biosensor applications. For the first time we report the formation of nanorods and microspheres of polyindole conducting polymer based on chemical synthesis using two immiscible (interfacial) and two miscible solvents respectively (without surfactant). Interfacial polymerization of polyindole is carried out by taking oxidizing agent in mild acid (HCl) and monomer in dichloromethane phases and polymerization in two miscible solvents is carried out by taking monomer in ethanol and oxidizing agent in mild acidic solution. Scanning electron microscope and atomic force microscope images of polyindole confirmed the formation of hollow spheres and nanorods. The possible mechanism for controlled morphologies is discussed based on formation of metastable micelles (for microspheres) and unstable micelles (for nanorods) in absence of surfactant. The mechanism is also supported by in-situ AFM studies. FT-IR data supported the 2,3 position polymerization of polyindole in both the morphologies. XRD data revealed that nanorod are more crystalline than microspheres, however, quite different from the amorphous conventional polymer obtained by electrochemical polymerization technique.

  15. A glucose sensor fabricated by piezoelectric inkjet printing of conducting polymers and bienzymes.

    Science.gov (United States)

    Yun, Yeon Hee; Lee, Byung Kook; Choi, Ji Suk; Kim, Sungwon; Yoo, Bongyoung; Kim, Yong Shin; Park, Kinam; Cho, Yong Woo

    2011-01-01

    Piezoelectric inkjet printing of polymers and proteins holds great promise for fabrication of miniaturized bioelectronic devices, such as biochips and biosensors. In this study, a bienzymatic glucose biosensor prototype based on poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS), glucose oxidase (GOD), and horseradish peroxidase (HRP) was fabricated by a piezoelectric inkjet printer. An aqueous bioelectrical ink containing PEDOT-PSS, GOD, and HRP was prepared and printed on an indium-tin-oxide (ITO)-coated poly(ethylene terephthalate) (PET) film. The PEDOT-PSS/GOD/HRP sensor was covered with a cellulose acetate membrane. The use of bienzymatic sensing combined with conducting polymers via piezoelectric inkjet printing showed a synergistic effect resulting in significant amplification of the response signal. The glucose sensor reached steady-state current density within 3 s, indicating a fast response time, and exhibited a linear dose-dependent electrochemical response with high sensitivity. The overall result demonstrates that a glucose sensor with high sensitivity could be readily fabricated by a piezoelectric inkjet printing system.

  16. Directed assembly of conducting polymers on sub-micron templates by electrical fields

    International Nuclear Information System (INIS)

    Highlights: ► Nanoscale patterns with dimensions of assembled PANi down to 100 nm were fabricated. ► We use electrophoretic and dielectrophoretic assembly to deposit PANi. ► Electrophoretic and dielectrophoretic assembly of PANi finished in less than 1 min. ► Effect of process parameters on assembly of PANi onto nanoscale pattern was studied. ► The assembled PANi can be transferred to other flexible substrates. - Abstract: Patterning of conducting polymer into sub-micron patterns over large areas at high rate and low cost is significant for commercial manufacturing of novel devices. Electrophoretic and dielectrophoretic assembly provide an easily scaled approach with high fabrication rates. In this work, electrophoretic and dielectrophoretic assembly were used to assemble polyaniline (PANi) into multiscale sub-micron size patterns in less than 1 min. The process was controlled by assembly time, amplitude, and frequency of the electric field. Dielectrophoretic assembly is preferable for manufacturing as it reduces damage to the templates used to control the assembly. Using this method, sub-micron patterns with dimensions of the assembled PANi down to 100 nm were fabricated over large areas in short times. The assembled PANi was further transferred to other flexible polymer substrates by a thermoforming process, providing a fast, easily controlled and promising approach for fabrication of nanoscale devices.

  17. "Bio-switch Chip" Based on Nanostructured Conducting Polymer and Entrapped Enzyme.

    Science.gov (United States)

    Kim, Daesan; Yoo, Haneul; Park, Jae Yeol; Hong, Seunghun

    2016-08-31

    We report a switchable biochip strategy where enzymes were entrapped in conducting polymer layers and the enzymatic reaction of the entrapped enzymes was controlled in real-time via electrical stimuli on the polymer layers. This device is named here as a "bio-switch chip" (BSC). We fabricated BSC structures using polypyrrole (Ppy) with entrapped glucose oxidase (GOx) and demonstrated the switching of glucose oxidation reaction in real-time. We found that the introduction of a negative bias voltage on the BSC structure resulted in the enhanced glucose oxidation reaction by more than 20 times than that without a bias voltage. Moreover, because the BSC structures could be fabricated on specific regions, we could control the enzymatic reaction on specific regions. In view of the fact that enzymes enable very useful and versatile biochemical reactions, the ability to control the enzymatic reactions via conventional electrical signals could open up various applications in the area of biochips and other biochemical industries. PMID:27576664

  18. An amperometric chloramphenicol immunosensor based on cadmium sulfide nanoparticles modified-dendrimer bonded conducting polymer.

    Science.gov (United States)

    Kim, Dong-Min; Rahman, Md Aminur; Do, Minh Hien; Ban, Changill; Shim, Yoon-Bo

    2010-03-15

    An amperometric chloramphenicol (CAP) immunosensor was fabricated by covalently immobilizing anti-chloramphenicol acetyl transferase (anti-CAT) antibody on cadmium sulfide nanoparticles (CdS) modified-dendrimer that was bonded to the conducting polymer (poly 5, 2': 5', 2''-terthiophene-3'-carboxyl acid (poly-TTCA)) layer. The AuNPs, dendrimers, and CdS nanoparticles were deposited onto the polymer layer in order to enhance the sensitivity of the sensor probes. The particle sizes were determined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The immobilization of dendrimers, CdS, and anti-CAT were confirmed using energy disruptive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and quartz crystal microbalance (QCM) techniques. The detection of CAP was based on the competitive immuno-interaction between the free- and labeled-CAP for active sites of the anti-CAT. Hydrazine was used as the label for CAP, and it electrochemically catalyzed the reduction of H(2)O(2) at -0.35 V vs. Ag/AgCl. Under optimized conditions, the proposed immunosensor exhibited a linear range of CAP detection between 50 pg/mL and 950 pg/mL, and the detection limit was 45 pg/mL. The immunosensor was examined in real meat samples for the analysis of CAP.

  19. Conducting polymer film-based immunosensors using carbon nanotube/antibodies doped polypyrrole

    Science.gov (United States)

    Tam, Phuong Dinh; Hieu, Nguyen Van

    2011-09-01

    Carbon nanotube/polypyrrole/antibodies polymer films were synthesized successfully on microelectrodes by electrochemical deposition. Electropolymerization was performed at optimal range between -0.8 and +0.8 V at a scan rate of 50 mV s-1 in an electrochemical mini-cell containing monomer pyrroles, carbon nanotubes, and goat IgGs. The conducting polymer films were characterized by Fourier transform infrared spectrometry, Raman spectra, and Field emission scanning electron microscopy. And then, it was prepared for immunosensor application to determine anti-goat IgGs. The results show that a linear range between 0.05 and 0.7 μg ml-1 for anti-goat IgGs detection was observed for immunosensor, a detection limit as low as 0.05 μg ml-1 and a response time of 1 min. The effect parameters of electropolymerization process on immunosensor response are also studied. It found that the immunosensor well active in 1.5 mg ml-1 CNT concentration, 2.5 mM pyrrole, 10 μg ml-1 goat IgGs.

  20. Conducting polymer film-based immunosensors using carbon nanotube/antibodies doped polypyrrole

    International Nuclear Information System (INIS)

    Carbon nanotube/polypyrrole/antibodies polymer films were synthesized successfully on microelectrodes by electrochemical deposition. Electropolymerization was performed at optimal range between -0.8 and +0.8 V at a scan rate of 50 mV s-1 in an electrochemical mini-cell containing monomer pyrroles, carbon nanotubes, and goat IgGs. The conducting polymer films were characterized by Fourier transform infrared spectrometry, Raman spectra, and Field emission scanning electron microscopy. And then, it was prepared for immunosensor application to determine anti-goat IgGs. The results show that a linear range between 0.05 and 0.7 μg ml-1 for anti-goat IgGs detection was observed for immunosensor, a detection limit as low as 0.05 μg ml-1 and a response time of 1 min. The effect parameters of electropolymerization process on immunosensor response are also studied. It found that the immunosensor well active in 1.5 mg ml-1 CNT concentration, 2.5 mM pyrrole, 10 μg ml-1 goat IgGs.