Conducting Polymer Composite Films Research Articles

Triode-type field emission array using carbon nanotubes and a conducting polymer composite prepared by electrochemical polymerization

We report a method to fabricate carbon nanotubes (CNT)/conducting polymer composite films for the application of CNTs to field emission displays. The composite was prepared by a combination of electrochemical polymerization of pyrrole and electrophoretic deposition of CNTs. We obtained a uniform CNT/conducting polypyrrole polymer composite film. The CNTs were mainly coated on protrusions of the polypyrrole film and emitted electrons without rubbing and stretching. We realized a triode-type field emission array (FEA) using the CNT/polypyrrol composite. This FEA showed that the emission current was modulated by gate voltage of 30 V. The film morphology and emission characteristics of the CNT/conducting polymer composite were studied using optical microscopy, scanning electron microscopy, and an emission test in vacuum.

Conductive polymer composite PET film with excellent antistatic properties

There have been few applications of conductive polymers as antistatic agents for poly(ethylene terephthalate) (PET) films for packaging, since they lack formability and transparency. A new antistatic film has been developed by coating PET with an alcohol-water solution containing a water soluble conductive polymer, sulphonated polyaniline (SPAn), and a water soluble or water dispersible polymer, which acts as a binder. It was found that this combination gave excellent antistatic properties. The SPAn antistatic polymer (ASP) composite PET films have special characteristics, such as good transparency, excellent antistatic properties (surface resistivity Rs=106-1010 Omega) at low humidity (15%RH), and good resistance to heat, water, and ammonia. In addition, ASP-PET films have a high capacity to retain their Rs values after drawing to a draw ratio of 3. Such characteristics of ASP-PET are ascribed not only to the fundamental properties of SPAn and the polyester binder, but also the affinity of the two polymers, which appears to result in the effective formation of a conductive network of SPAn within the polyester binder.

PROPERTIES OF CONDUCTING POLYMER DONOR-ACCEPTOR COMPOSITE FILMS AND PHOTOVOLTAIC CHARACTERISTICS OF JUNCTION DEVICES

To realize an efficient photovoltaic device,one of the methods of creating a large interfacial area at which the effective dissociation of excitons occurs is to mix an electron donor material with an electron acceptor material.The new soluble conducting polymer-dye ROPPV(poly(2,5-dialkoxy-p-phenylene vinylene)/ N,N'-diphenyl glyoxaline-3,4,9,10-perylene tetracarboxylic acid diacidamide (PV) composite was prepared.Electrical and optical properties of soluble conducting polymer composite films,and current-voltage(I－V) characteristics and photocurrent spectra of photovoltaic cells are discussed.Our results show that the soluble conducting polymer-dye composite represents a new class of organic semiconducting materials that can be used to manufacture photovoltaic cells.

Properties of Conducting Polymer-Dye Composite and Photovoltaic Characteristics of Junction Devices

We have prepared new soluble conducting polymer/dye composite and photovoltaic cells with three different architectures using soluble conducting polymer (CP) as hole transport material and perylene derivatives (PV) as electron transport material. These architectures comprise single-layer (ITO/CP-PV/Al) and double-layer (ITO/CP-PV/PV/Al) as well as three-layer (ITO/CP-C60/CP-PV/PV/Al) structures. Electrical and optical properties of soluble conducting polymer composite film and current-voltage characteristics and photocurrent spectra of photovoltaic cells are discussed. The results show that the soluble conducting polymer-dye composite represents a new class of organic semiconducting material that can be used to manufacture photovoltaic cells.

New Ionic Conducting Polymer Composite Films Based on Partially Phosphorylated Poly(vinyl alcohol) and Poly(acrylic acid)

Abstract Ionic conductivity of a composite film consisting of partially phosphorylated poly(vinyl alcohol) (P-PVA) and poly(acrylic acid) (PAA) is increased about three orders of magnitude over that of P-PVA film.

Electrochemical oxygen reduction at composite films of Nafion ®, polyaniline and Pt

Conducting polymer composite films comprised of polyaniline (PANI) and Nafion are prepared and investigated as a matrix for platinum (Pt) particles deposited both chemically and electrochemically. The resulting electrocatalytic films are assessed with respect to their potential use for the electrochemical reduction of oxygen. The permeability of a PANI—Nafion film to dissolved oxygen is determined to be ∼50% larger when compared to PANI—camphorsulfonic acid (CSA). A chemical method for dispersing Pt in the composite films is developed which makes use of the reducing power of alcohols present in commercial Nafion solution. Films cast from a solution of PANI and Nafion containing chemically reduced platinum demonstrate a marked improvement in electrocatalytic activity compared to films prepared in the absence of PANI. These composite films are compared with films cast from a suspension of Nafion, PANI and Pt black, with similar results.

New transparent, colorless, metallically conductive polymer films and their electrochemical transformations

New surface conductive polymer composite films exhibiting extraordinary properties: high conductivity with metallic temperature dependence and exceptionally high transparency are presented. The conducting networks in these materials are formed of plate-like nanocrystals of bis(ethylenedioxy)tetrathiafulvalene (BEDO-TTF) salts with iodine or bromine. The films with bromine salts are colorless and transparent while those with iodine are colored. It is demonstrated that colored films with (BEDO-TTF)/iodine networks can be electrochemically transformed into highly transparent, practically colorless materials without deterioration of the conducting network. The resulting metallically conducting polymer materials show the highest transparency among conductive composites reported so far.

Polypyrrole—polypropylene composite films: preparation and properties

Abstract Polypyrrole—polypropylene conducting polymer composite films with good mechanical properties and high electrical conductivity were prepared using a two-direction permeation/diffusion polymerization method. The oxidant used was iron( III ) chloride. Polypropylene microporous films prepared by the biaxial stretching technique were used as the matrix material. The maximum conductivity of these composite films, 6.0 S cm−1, is of the same order of magnitude as that of pure polypyrrole, 4.5 S cm−1, which was synthesized by chemical oxidation of pyrrole monomer in aqueous solution. The composite films exhibit quite uniform mechanical properties in the film plane. Young's modulus is in the range 0.4–0.8 GPa, tensile strength 40–85 MPa and elongation at break 90–200%, maintaining the mechanical properties of polypropylene in the composite. Polymerization conditions, including reaction time, reaction temperature and concentrations of the pyrrole and FeCl3 solutions, have a great influence on the structure and properties of the composite films. The structure of the conducting polymer in the composite films was characterized by X-ray photoelectron spectroscopy and the surface morphology of the films was investigated using scanning electron microscopy. Two kinds of surface structure were observed, one is a loose particle structure and the other is a compacted surface structure.

Electrically conductive composite prepared by template polymerization of pyrrole into a complexed polymer

AbstractElectrically conducting polymer composite films have been synthesized by the exposure of poly(4‐vinylpyridine) complexed with cupric ions to pyrrole and water vapor. To immobilize a stoichiometric amount of the oxidant inside the polymer matrix, the ratio of poly(4‐vinylpyridine)/cupric ion = 1.8 was chosen. Polypyrrole was formed in this tailored structure by a template polymerization process. Opaque polymer composite films with electrical conductivity up to 60 (Ω cm)−1 have been obtained by this method, However, slightly colored transparent composite thin films with a conductivity as high as 50 (Ω cm)−1 were also produced. The electrically conducting polymer composite films and the metal‐polymer complex have been characterized by XPS and IR spectroscopy, elemental analysis, EDX, and scanning electron microscopy. The polymerization process was also followed by use of a quartz crystal microbalance. © 1994 John Wiley & Sons, Inc.

Conducting polymers prepared by template polymerization: polypyrrole

Electrically conducting polymer composite films have been synthesized from the exposure of poly(4-vinylpyridine) (P-4VP) complexed with an oxidizing agent such as cupric chloride or ferric chloride to pyrrole and water vapour. Polypyrrole was formed in the matrix polymer of P-4VP complexed with iron ions when the mole ratio of polymer to oxidant was less than 2, whereas the growth of polypyrrole occurred at all P-4 VP Cu 2+ ratios. Polymer composite films with electrical conductivities up to 100 (Ωcm) −1 have been obtained by this method. Transparent thin films with a high electrical conductivity were also produced. The electrically conducting polymer composite films have been characterized by X-ray photoelectron, ultraviolet/visible and infra-red spectroscopy and by scanning electron microscopy.