Showing papers in "Synthetic Metals in 1991"

TL;DR: The use of modern organic conductors (as opposed to the more traditional carbon black or salts) as fillers for the production of antistatic polymers is advantageous, especially for the formation of films.

TL;DR: In this paper, the interconversion of different oxidation states of polyanilines has been studied and it is concluded that the poly-aniline bases (NMP solution) exist only in three discrete oxidation states at the molecular level.

TL;DR: In this article, it has been shown that a polypyrrole (PPy) chain is sensitive to the pH of the solution and deprotonation has only a small effect on the electronic structure of the chain, causing only slight increase of the PPy conductivity.

TL;DR: In this article, the stability of polyaniline backbone was investigated for both conducting and insulating forms and it was shown that the covalently bonded sulfonic groups increased the stability.

TL;DR: In this article, the authors analyzed the structural parameters which control the charge transport properties in conjugated molecular semiconductors and showed that the extent of conjugation and absence of structural defects are the most significant parameters for achieving high carrier mobility in these molecular materials.

TL;DR: In this paper, the electrochemistry of conducting polymers is described in relation to electrosynthesis and charge storage properties, and an overview of prospective applications is provided with an overview with prospective applications.

TL;DR: In this article, the π-electron donor molecule BEDT-TSeF was synthesized and the key step in their synthesis is the isolation of the reactive 1,4-ethylenedithio-5,6-diselenolate dianion as its titanocene complex which easily reacts with triphosgene to give 4,5-ethyledithio 1,3-diselinol-2-one.

TL;DR: In this article, a potential profiling technique was used to detect the intermediacy of the fully oxidized pernigraniline oxidation state (readily isolable as the base form).

TL;DR: In this article, the dependency of the conductivity of polyaniline (emeraldine oxidation state) on its molecular weight has been determined and the degree of crystallinity, tensile strength, and conductivity (after doping) on draw ratio was determined.

TL;DR: In this article, a spin-coated polyaniline (PANi) was obtained with conductivities in the range 60-70 S/cm and anisotropy σ  /σ ⊥ of up to 24.

TL;DR: In this article, the authors investigated the electrical conduction mechanism of polypyrrole films containing various counter ions and showed that the conduction is dominated more strongly by tunneling than by hopping in a lower temperature region.

TL;DR: A new type of aluminum solid electrolytic capacitor in which electroconducting polymer is applied as an electrolyte was developed in this article, which not only has good frequency and temperature characteristics but also has good thermal and moisture stabilities.

TL;DR: The most highly oxidized polyaniline, in the form of pernigraniline base, can be synthesized as an analytically and oxidatively pure solid (powder or large free-standing films) by the controlled oxidation of emeraldine base by m -chloroperbenzoic acid or directly from aniline by oxidative polymerization with (NH 4 ) 2 S 2 O 8.

TL;DR: In this article, the results of polyaniline (PANI) interaction with water and ammonia vapours were reported and the four-probe method for conductivity measurements and the thermally programmed desorption (TPD) method were used.

TL;DR: In this paper, gas permeability values are reported for films of the conducting polymer polyaniline in the emeraldine oxidation state, and significant improvements in gas selectivity are observed for all gas pairs studied.

TL;DR: In this article, a series of strictly α, α′-coupled oligomers of thiophene containing 3,4,5,6,7,9, and 11 rings and provided with 0 to 5 side groups (n-butyl, n-dodecyl or tertbutyl) have been prepared and their melting points, solubilities in chloroform, UV-vis absorption and emission spectra of both solutions and solids, and conductivities after doping with iodine have been measured.

TL;DR: In this article, the temperature profiles of the degradation processes have been mapped using thermogravimetry (TG) in conjunction with thermal volatilization analysis (TVA), and product distributions have been ascertained using the fractionating capability of the TVA system in combination with ancillary techniques of analysis such as infrared (IR) and proton nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS).

TL;DR: In this paper, the macroscopic structure, morphology and interchain phenomena of conductive polymers are discussed, as well as their macroscopy structure and morphology in terms of the thermopower which is a zero current transport coefficient.

TL;DR: In this article, the syntheses, structures, selected physical properties, and band electronic structures of three copper dicyanamide halide salts of bis(ethylenedithio)tetrathiafulvalene [κ-(ET) 2 Cu[N(CN) 2 ]X, where X = Cl, Br, and I] are discussed.

TL;DR: In this article, the authors showed that the electrical properties of the oligomers are clearly related to their degree of conjugation, and that the field effect mobility is sensitive to the nature and chain length of the conjugated organic oligomers.

TL;DR: In this paper, an evolution of the polaron-bipolaron gap has been shown to lead to an evolution in both the peak current and the spin concentration, in contradiction with the last prediction.

TL;DR: In this article, the PPy-PET composite films (30 μm thickness) possessing both high transmittance (70 −85, 633 nm) and conductivity (0.03 −0.10 S/cm) can be consistently prepared by this diffusion-oxidation procedure under the optimum reaction temperature (in the range 0 −10 °C and reaction time (5 −10 h).

TL;DR: In this article, a transport mechanism in terms of tunneling conduction between adjacent particles is proposed to explain the observed experimental behaviour of poly(ethylene)-graphite composites.

TL;DR: In this article, the use of conducting polymers for EMI shielding is a potential application and measurements have been made on poly(3-octyl thiophene) (P3OT) blends with polystyrene (PS), polyvinyl chloride (PVC) and ethyl-vinyl acetate (EVA) as matrix materials.

TL;DR: In this paper, the drift velocities of the organic photoconductors naphthalene, anthracene, and perylene drift moblities were measured down to low temperatures, where up to 400 cm 2 /Vs were reached and sublinear velocity/field dependences observed.

TL;DR: In this article, the anomalous spin-splitting phenomenon which exhibits the field-dependent spin splitting separation has been observed, assuming an antiferromagnetic exchange interaction between the electrons in the spin-up and spin-down states.

TL;DR: In this article, the authors found that FePS 3, VPS 3 and V 0.78 PS 3 crystals have electrical conductivity higher than 10 −5 S cm −1, while MnPS 3, NiPS3, and ZnPS 3 have conductivities lower than 10−9 S cm−1 at room temperature.

TL;DR: In this article, it was shown that poly(3-methylthiophene) exhibits a relaxation effect when maintained in its neutral state, and the characteristics of this effect are very similar to those observed before in polyaniline.

TL;DR: In this article, a series of copolymers of the 3-alkylthiophenes was prepared using a 1:1 molar feed ratio of the two monomers and the molecular weights of the materials decreased with decreasing side chain length.

TL;DR: In this article, a transparent and conducting polyaniline-poly(ethylene terephthalate) (PAn-PET) composite was synthesized chemically by exposing PET films (10 μm thickness) sorbing aniline monomer to the vapours of aqueous (NH 4 ) 2 S 2 O 8 solution containing HCl.