Showing papers on "Conductive polymer published in 1998"
TL;DR: In this article, the authors showed that nanometre-sized ceramic powders can be used as solid plasticizers for polyethylene oxide (PEO) electrolytes to prevent crystallization on annealing from amorphous state above 60°C.
Abstract: Ionically conducting polymer membranes (polymer electrolytes) might enhance lithium-battery technology by replacing the liquid electrolyte currently in use and thereby enabling the fabrication of flexible, compact, laminated solid-state structures free from leaks and available in varied geometries1. Polymer electrolytes explored for these purposes are commonly complexes of a lithium salt (LiX) with a high-molecular-weight polymer such as polyethylene oxide (PEO). But PEO tends to crystallize below 60 °C, whereas fast ion transport is a characteristic of the amorphous phase. So the conductivity of PEO–LiX electrolytes reaches practically useful values (of about 10−4 S cm−1) only at temperatures of 60–80 °C. The most common approach for lowering the operational temperature has been to add liquid plasticizers, but this promotes deterioration of the electrolyte's mechanical properties and increases its reactivity towards the lithium metal anode. Here we show that nanometre-sized ceramic powders can perform as solid plasticizers for PEO, kinetically inhibiting crystallization on annealing from the amorphous state above 60 °C. We demonstrate conductivities of around 10−4 S cm−1 at 50 °C and 10−5 S cm−1 at 30 °C in a PEO–LiClO4 mixture containing powders of TiO2 and Al2O3 with particle sizes of 5.8–13 nm. Further optimization might lead to practical solid-state polymer electrolytes for lithium batteries.
2,695 citations
TL;DR: The motivation for lithium battery development and a discussion of ion conducting polymers as separators begin this review, which includes a short history of polymer electrolyte research, and a summary of the major parameters that determine lithium ion transport in polymer matrices.
Abstract: The motivation for lithium battery development and a discussion of ion conducting polymers as separators begin this review, which includes a short history of polymer electrolyte research, a summary of the major parameters that determine lithium ion transport in polymer matrices, and consequences for solid polymer electrolyte development. Two major strategies for the application of ion conducting polymers as separators in lithium batteries are identified: One is the development of highly conductive materials via the crosslinking of mobile chains to form networks, which are then swollen by lithium salt solutions ("gel electrolytes"). The other is the construction of solid polymer electrolytes (SPEs) with supramolecular architectures, which intrinsically give rise to much enhanced mechanical strength. These materials as yet exhibit relatively common conductivity levels but may be applied as very thin films. Molecular composites based on poly(p-phenylene)- (PPP)-reinforced SPEs are a striking example of this direction. Neither strategy has as yet led to a "breakthrough" with respect to technical application, at least not for electrically powered vehicles. Before being used as separators, the gel electrolytes must be strengthened, while the molecularly reinforced solid polymer electrolytes must demonstrate improved conductivity.
1,273 citations
TL;DR: In this article, the behavior of PANI is shown to be subject to the same basic principles as the polymerization process itself, where the direction and establishment of equilibrium are dependent on the oxidation potentials and concentrations of the reactants.
870 citations
TL;DR: The properties of imidazole (pyrazole) as a solvent for acidic protons in polymers and liquids are reported in this article, where the creation of protonic defects and the mobility of protons are found to be similar to the situation in corresponding water containing systems.
557 citations
TL;DR: In this paper, the authors present an updated review on the various aspects of conductive polymers, viz., synthesis, doping, structure analysis and proposed utility for further study of the future scientific and technological developments in the field of conductively polymers.
435 citations
TL;DR: A series of dual polymer electrochromic devices (ECDs) based on 12 complementary pairs of conducting polymer films have been constructed using 3,4-ethylenedioxythiophene-containing conducting polymers as discussed by the authors.
Abstract: A series of dual polymer electrochromic devices (ECDs) based on 12 complementary pairs of conducting polymer films have been constructed using 3,4-ethylenedioxythiophene-containing conducting polymers. Poly[3,6-bis(2-(3,4-ethylenedioxythiophene))-N-methylcarbazole] (PBEDOT-NCH3Cz), poly[3,6-bis(2-(3,4-ethylenedioxythiophene))-N-eicosylcarbazole] (PBEDOT-NC20H41Cz), and poly[4,4‘-bis(2-(3,4-ethylenedioxythiophene))biphenyl] (PBEDOT-BP) were utilized as anodically coloring polymers that electrochemically switch between an oxidized deep blue absorptive state and a transmissive (orange or yellow) reduced state. Poly(3,4-ethylenedioxythiophene) (PEDOT) and its alkyl derivatives (PEDOT-C14H29 and PEDOT-C16H33) have been used as high-contrast cathodically coloring polymers that switch between a deep blue absorptive state in the reduced form and a sky blue, highly transmissive state in the oxidized form. The dual polymer ECDs were constructed by separating complementary pairs of EC polymer films, deposited on ITO...
423 citations
TL;DR: In this paper, sulfonated polymers containing 65 mol% sulfonic acid showed a high protonconductivity of 10−2−10−4 S cm−1 at room temperature, which is in agreement with the strong water absorption of the former compound.
417 citations
TL;DR: Electrically conducting organic polymers as discussed by the authors are a class of synthetic metals that combine the chemical and mechanical properties of polymers with the electronic properties of metals and semiconductors, and have generated tremendous interest due to their potential applications in batteries, electrochromic display devices, sensors etc.
320 citations
TL;DR: In this article, the structure, doping, conductivity and thermal stability of reduced polyaniline (PANI-R) were studied by elemental analysis, FT-i.r., solid-state 13C-NMR, XPS and TGA.
283 citations
TL;DR: In this article, the Raman spectroscopy was used to correlate the molecular structure of the nanoscopic tubules with their conducting properties by determining the relative conjugation length in the PPy chains.
268 citations
TL;DR: In this paper, DeWice et al. used self-assembling trioctylphosphine oxide, TOPO, capped n-type 20-40 A diameter CdSe nanoparticles and 1,6-hexadecanethiol, HDT, onto p-doped semiconducting polymers.
Abstract: Ultrathin films have been prepared by self-assembling trioctylphosphine oxide, TOPO, capped n-type 20-40 A diameter CdSe nanoparticles and 1,6-hexadecanethiol, HDT, onto p-doped semiconducting polymers, chemically deposited poly(3-methylthiophene), PMeT (for DeWice A), and electrochemically deposited poly- (pyrrole), Ppy (for DeWice B). The semiconducting polymers have, in turn, been electrochemically layered (for DeWice A) or layer-by-layer chemically assembled (for DeWice B) onto derivatized conducting substrates. The ultrathin films have been characterized by absorption and emission spectroscopy, transmission electron microscopy, scanning force microscopy, X-ray photoelectron spectroscopy, and by electrochemical measure- ments. By controlling the level of doping into the p-type junction, it was possible to prepare dissymmetrical junctions and observe a rectifying behavior in the forward direction and a Zener breakdown in the reverse direction for Au/PMeT/(HDT/CdSe)3, DeWice A, and for Au/MEA/Ppy/(HDT/CdSe)3, DeWice B. Additionally, Au/MeA/PAH/CdSe (PAH ) poly(allylamine hydrochloride)), Au/MEA/Ppy/PSS/CdSe (PSS ) polystyrene sulfonate), and Au/MEA/Ppy/R-ZrP/CdSe (R-ZrP )R zirconium phosphate) films have been prepared and characterized.
TL;DR: In this paper, the status and potentials of commercial applications of conductive polymers, mainly polyaniline, are discussed, and it is shown that dispersion has evolved to be the necessary key for making conductives suitable for industrial applications, at least if "doped" conjugated polymers are under review.
TL;DR: In this paper, an emulsion process was developed for the direct synthesis of the emeraldine salt of polyaniline (PANI) that is soluble in organic solvents.
Abstract: An emulsion process has been developed for the direct synthesis of the emeraldine salt of polyaniline (PANI) that is soluble in organic solvents. The process entails formation of emulsion particles with a mean hydrodynamic diameter of 150 nm and consisting of a water-soluble organic solvent (e.g., 2-butoxyethanol), a water-insoluble organic acid (e.g., dinonylnaphthalenesulfonic acid), aniline, and water. Aniline is protonated by the organic acid to form a salt which partitions into the organic phase. As oxidant (ammonium peroxydisulfate) is added to the reaction mixture, PANI intermediates are formed in the organic phase. As the reaction proceeds, the emulsion flocculates, forming a two-phase system. The reaction features an induction period followed by an exothermic polymerization, at which time soluble PANI forms in the organic phase. The reaction progress is conveniently monitored by temperature, pH, and open circuit potential. When dinonylnaphthalenesulfonic acid (DNNSA) is employed as the organic ac...
TL;DR: In this article, the Seebeck coefficient and electric conductivity in polyaniline and polypyrrole at different doping levels were measured and it was shown that at 300 K, the general correlation that the logarithm of the electrical conductivity varies linearly with the seebeck coefficient on doping, but with a proportionality substantially in excess of a prediction from simple theory for a single type of mobile carrier.
Abstract: We have measured the Seebeck coefficient and electric conductivity in the air-stable conducting polymers polyaniline and polypyrrole at different doping levels. We find, at 300 K, the general correlation that the logarithm of the electrical conductivity varies linearly with the Seebeck coefficient on doping, but with a proportionality substantially in excess of a prediction from simple theory for a single type of mobile carrier. The correlation is unexpected in its universality and unfavorable in its consequences for thermoelectric applications. A standard model suggests that conduction by carriers of both signs may occur in these doped polymers, which thus leads to reduced thermoelectric efficiency. We also show that polyacetylene (which is not air stable), does exhibit the correlation with the expected proportionality, and, thus, its properties could be more favorable for thermoelectricity.
Book•
27 Mar 1998
TL;DR: In this article, a novel class of nonlinear optical and electric functional polymers conjugated polynitriles, a class of polymers with second harmonic generation in poled polymer waveguides using co-propagating geometries, is presented.
Abstract: Part 1 Conductive polymers: polyanaline as a corrosion barrier optimization of electrical and redox properties of electrogenerated polypyroles heterocycle-based electroconductive polymers electrochemical characteristics of conducting polymers anisotropy in electrically conducting polymers basic methods of synthesis and characterization of electronically conducting polymers. Part 2 Nonlinear optical polymers: nonlinear optical characterization of polymers conjugated polynitriles - a novel class of nonlinear optical and electric functional polymers second harmonic generation in poled polymer waveguides using co-propagating geometries design and fabrication of nonlinear polymer integrated optic devices fabrication and characterization of electrooptic polymer waveguide modulator for photonic applications. Part 3 Advances in electrical and optical polymer systems: optical and spectroscopic investigations on the supramolecular assemblies of optoelectronic materials towards organic functional devices using ionized cluster beam deposition method electrochemical synthesis and characterization of conjugated polymers optically active conjugated polymers with main chain chirality coordination polymers - infinite 1-D, 2-D and 3-D frameworks based upon transition metals and polyfunctional ligands interfacial aspects in the manufacture of soft contact. Part 4 Dielectric and field responsive materials: electrical responses of polymer gels electric field alignment of polymer materials exhibiting long-range order ferroelectric liquid crystalline polymers electrical impedance properties of chemically responsive hydrogels ferroelectricity and peizoelectric biopolymers. (Part contents).
TL;DR: In this paper, a predoctoral fellowship for GPC analysis was presented, which was supported by the Ministerio de Educacion y Ciencia (Spain, MEC-AECI) and CONACYT (Mexico).
Abstract: This work was supported by
DGICYT (Spain, PB93-0122) and CICYT (Spain, MAT
96-1057-CO2-01). We also thank the Ministerio de
Educacion y Ciencia (Spain, MEC-AECI) and CONACYT
(Mexico) for a predoctoral fellowship awarded to
M.L.C. We thank Dr. S. Borros and I. Folch for their
help in performing GPC analysis.
TL;DR: Several types of lithium ion conducting polymer electrolytes have been synthesized by hot-pressing homogeneous mixtures of the components, namely, poly(ethylene oxide) (PEO) as the polymer matrix, lithium trifluoromethane sulfonate (LiCF{sub 3}SO{ sub 3}), and lithium tetrafluoroborate (LiBF{sub 4}), respectively, as the lithium salt, and lithium gamma-aluminate {gamma}-LiAlO{sub 2}, as a ceramic filler.
Abstract: Several types of lithium ion conducting polymer electrolytes have been synthesized by hot-pressing homogeneous mixtures of the components, namely, poly(ethylene oxide) (PEO) as the polymer matrix, lithium trifluoromethane sulfonate (LiCF{sub 3}SO{sub 3}), and lithium tetrafluoroborate (LiBF{sub 4}), respectively, as the lithium salt, and lithium gamma-aluminate {gamma}-LiAlO{sub 2}, as a ceramic filler. This preparation procedure avoids any step including liquids so that plasticizer-free, composite polymer electrolytes can be obtained. These electrolyte have enhanced electrochemical properties, such as an ionic conductivity of the order of 10{sup {minus}4} S/cm at 80--90 C and an anodic breakdown voltage higher than 4 V vs. Li. In addition, and most importantly, the combination of the dry feature of the synthesis procedure with the dispersion of the ceramic powder, concurs to provide these composite electrolytes with an exceptionally high stability with the lithium metal electrode. In fact, this electrode cycles in these dry polymer electrolytes with a very high efficiency, i.e., approaching 99%. This in turn suggests the suitability of the electrolytes for the fabrication of improved rechargeable lithium polymer batteries.
TL;DR: In this paper, the authors give guidelines for the design of low-band-gap π-conjugated oligomers with different chain lengths containing electron-donating thiophene or pyrrole rings and electronwithdrawing 2,1,3-benzothiadiazole (like the one shown here) or quinoxaline rings.
Abstract: Some practical guidelines for the design of novel low-band-gap systems. Various donor–acceptor π-conjugated oligomers with different chain lengths containing electron-donating thiophene or pyrrole rings and electron-withdrawing 2,1,3-benzothiadiazole (like the one shown here) or quinoxaline rings have been synthesized by Stille cross-coupling. The UV/Vis absorption behavior of these systems is used to give guidelines for donor–acceptor based low-band-gap or even intrinsically conducting polymers.
TL;DR: In this paper, the capacity of polyaniline in the emeraldine oxidation state to protect the surface against corrosion processes was evaluated for carbon and stainless steel in contact with 3% sodium chloride aqueous solution saturated with air.
TL;DR: In this paper, the properties of polymer composites with superparamagnetic nanoparticles are discussed and methods of preparation and properties of polyaniline/iron oxide polymers are discussed.
TL;DR: In this paper, the porosity of polyaniline polymers is investigated and the capacitive current plateau in the cyclic voltammogram and the large series ac capacitance is shown to be related to continuous faradaic charge transfer at potentials beyond the first oxidation wave.
TL;DR: In this article, the authors studied the SERS spectra under 1064 nm excitation for two forms of polyaniline, one of the emeraldine base type and the other of the Emeraldine salt type.
TL;DR: In this paper, the authors employ porous filtration membranes as templates to entrap and align particles along the long axis of the pores, and then link them by 1,6-hexanedithiol to make shorter linear nanoparticle arrays (e.g., (Au particle)n, n ≤ 5).
Abstract: New strategies are reported for assembling Au nanoparticles into coupled 1D arrays. The mehods employ porous filtration membranes as templates to entrap and align particles along the long axis of the pores. Following alignment, nanoparticles were linked by 1,6-hexanedithiol to make shorter linear nanoparticle arrays (e.g., (Au particle)n, n ≤ 5) or with the organic conductive polymer polypyrrole to make longer 1D arrays. These methods provide new opportunities for characterizing the electronic and optical properties of coupled nanoscopic solid-state materials.
TL;DR: In this paper, the optical properties and thickness of poly(3,4-ethylenedioxythiophene) (PEDOT) layers were extracted by simultaneously fitting optical functions for multiple samples using a recently discussed 4×4 matrix formalism.
TL;DR: In this paper, a series of conductive polymer-V 2 O 5 nanocomposites that have a structure comprised of layers of polymer chains interleaved with inorganic oxide lamellae were examined.
TL;DR: In this paper, the reduction of pernigraniline to emeraldine with FeCl2 was investigated, and the as-synthesized and deprotonated emeraldines were purified by extraction with chloroform.
Patent•
05 Nov 1998TL;DR: A fluorocarbon based conductive polymer and method of making such polymer are disclosed in this article, which is advantageously used in electroluminescent devices and can be used in a variety of applications.
Abstract: A fluorocarbon based conductive polymer and method of making such polymer are disclosed. The conductive polymer is advantageously used in electroluminescent devices.
TL;DR: In this paper, the interaction between the polypyrrole and V2O5 aerogel in the nanocomposites was probed using IR spectroscopy, and the results suggest that the inorganic and organic components strongly interact during the initial stages, thus perhaps impeding the vanadium condensation process.
Abstract: Vanadium pentoxide/polypyrrole aerogel (ARG) composites have been synthesized by sol–gel routes, and investigated as cathode materials in Li batteries. The primary method utilized simultaneous polymerisation of pyrrole and vanadium alkoxide precursors. Hydrolysis of VO(OC3H7)3 using pyrrole–water–acetone mixtures yielded monolithic green–black gels with polypyrrole/V ratios ranging from 0.15 to 1.0. Supercritical drying yielded high surface (150–257 m2 g–1) aerogels with densities between 0.1 and 0.2 g cm–3 , that were of sufficient mechanical integrity to allow them to be cut without fracturing. TEM studies of the ARGs show that they are comprised of fibers similar to that of V2O5 ARGs, but with a significantly shorter chain length. The interaction between the polypyrrole (PPy) and V2O5 aerogel in the nanocomposites was probed using IR spectroscopy. Our results suggest that the inorganic and organic components strongly interact during the initial stages, thus perhaps impeding the vanadium condensation process. Hence, the PPy/V2O5 nanocomposites exhibited lower electrical conductivity with increased polypyrrole content. The addition of (NH4)2S2O8 as an oxidizing agent improved the conductivity of the nanocomposites. The deleterious effect of the conductive polymer on the bulk conductivity does not necessarily affect the electrochemical properties of these materials. Nanocomposite materials that were subjected to post-oxidative treatment show enhanced Li insertion capacity compared to the pristine ARG. The physical properties of these ‘nanocomposite aerogels’ are different from ‘microcomposites’ prepared by an alternate route, in which the oxide gel is formed in the presence of a dispersion of preformed micrometer-sized polypyrrole particles.
TL;DR: In this paper, a new type of polymer electrolyte which contains rigid polymer rather than the flexible low Tg polymers used in conventional polymer electrolytes is described, which is called rigid polymeric electrolyte.
Abstract: A new type of polymer electrolyte which contains rigid polymer rather than the flexible low Tg polymers used in conventional polymer electrolytes is described. The new type of polymer electrolyte e...