Electrostatic interaction hybrids from water-borne conductive polyaniline and inorganic precursor containing carboxyl group

Electrostatic interaction conductive hybrids were prepared in water/ethanol solution by the sol-gel process from inorganic sol containing carboxyl group and water-borne conductive polyaniline (cPANI). The electrostatic interaction hybrids film displayed 1-2 orders of magnitude higher electrical conductivity in comparison with common hybrids film, showing remarkable conductivity stability against water soaking. Most strikingly, it displayed ideal electrochemical activity even in a solution with pH = 14, which enlarged the conducting polyaniline application window to strong alkaline media.

Conductive hybrid film from polyaniline and polyurethane-silica

In order to improve the mechanical performance and water resistance of water-borne conducting polyaniline film, conducting polyaniline/polyurethane-silica hybrid film was prepared in aqueous solution employing silanol-terminated polyurethane and methyltriethoxysilane as sol-gel precursors. The hybrid film showed surface resistivity of 10(8) Omega even though the conducting polyaniline loading was only 10 wt% (or 1.5 wt% of polyaniline), and the mechanical performance as well as water resistance was significantly improved, making it suitable for antistatic application. Therefore, a practical route to water-borne processing of conducting polyaniline is disclosed.

Conductive property of multiwall carbon nanotubes-PEO-salt nanocomposite film

By adding a small amount of multiwall carbon nanotubes (MWNTs) to polyethylene oxide (PEO) and a salt system, a new type of nanocomposite film was constructed. At ambient temperature, the conductivity of the PEO-salt-0.5 wt % MWNTs was nearly three orders of magnitude higher than that of the PEO-salt system. The conductive property of the nanocomposite film was characterized by ac impedance and the differential scanning calorimetry technique.

Electrically conductive, melt-processed ternary blends of polyaniline/dodecylbenzene sulfonic acid, ethylene/vinyl acetate, and low-density polyethylene

Although polyaniline (PANI) has high conductivity and relatively good environmental and thermal stability and is easily synthesized, the intractability of this intrinsically conducting polymer with a melting procedure prevents extensive applications. This work was designed to process PANI with a melting blend method with current thermoplastic polymers. PANI in an emeraldine base form was plasticized and doped with dodecylbenzene sulfonic acid (DBSA) to prepare a conductive complex (PANI-DBSA). PANI-DBSA, low-density polyethylene (LDPE), and an ethylene/vinyl acetate copolymer (EVA) were blended in a twin-rotor mixer. The blending procedure was monitored, including the changes in the temperature, torque moment, and work. As expected, the conductivity of ternary PANI-DBSA/LDPE/EVA was higher by one order of magnitude than that of binary PANI-DBSA/LDPE, and this was attributed to the PANI-DBSA phase being preferentially located in the EVA phase. An investigation of the morphology of the polymer blends with high-resolution optical microscopy indicated that PANI-DBSA formed a conducting network at a high concentration of PANI-DBSA. The thermal and crystalline properties of the polymer blends were measured with differential scanning calorimetry. The mechanical properties were also measured.

Preparation of highly conductive, self-assembled gold/polyaniline nanocables and polyaniline nanotubes

One-dimensional gold/polyaniline (Au/PANI-CSA) coaxial nanocables with an average diameter of 5060 nm and lengths of more than 1 mu m were successfully synthesized by reacting aniline monomer with chlorauric acid (HAuCl4) through a self-assembly process in the presence Of D-camphor-10-sulfonic acid (CSA), which acts as both a dopant and surfactant. It was found that the formation probability and the size of the Au/PANI-CSA nanocables depends on the molar ratio of aniline to HAuCl4 and the concentration of CSA, respectively. A synergistic growth mechanism was proposed to interpret the formation of the Au/PANI-CSA nanocables. The directly measured conductivity of a single gold/polyaniline nanocable was found to be high (approximate to 77.2S cm(-1)). Hollow PANI-CSA nanotubes, with an average diameter of 50-60 nm, were also obtained successfully by dissolving the Au nanowire core of the Au/PANI-CSA nanocables.

A novel nanometer-scale "gold electrode-molecular wires-silver" junction: An efficient test bed for electrochemical investigation of electron transportation through molecular wires in self-assembled monolayers

A novel "gold electrode-molecular wires-silver" junction was facilely fabricated for electrochemical study on the electron transportation through molecular wires. Rapid electron transportation through this sandwich-like structure was indeed observed by cyclic voltammograms and ac impedance measurements. Since rather reproducible and reliable results are easily available by electrochemical techniques, it would be an efficient and reliable test bed for electrochemical investigation of charge transportation through molecular wires in self-assembled monolayers on electrodes.

Column chromatographic purification free synthesis of long-chain monodisperse oligo(1,4-phenyleneethynylene)s: towards large-scale automatic synthesis of molecular wires

A facile, mild and rapid solid phase synthetic route free of column chromatographic purification to the synthesis of soluble monodisperse long-chain oligo(1,4-phenyleneethynylene)s is presented.

Highly sensitive electrogenerated chemiluminescence produced at Ru(bpy)(3)(2+) in Eastman-AQ55D-carbon nanotube composite film electrode

The electrochemistry and electrogenerated chemilurninescence (ECL) of tris(2,2-bipyridyl)ruthenium(II) ion-exchanged in Eastman-AQ-carbon nanotube (CNT) composite films were investigated at a glassy carbon (GC) electrode. Eastman-AQ55D is a poly (ester sulfonic acid) cation exchanger available in a commercial dissolved form. It is much more hydrophilic than Nafion due to its unique structure, so Ru(bpy)(3)(2+) does not diffuse into the hydrophobic region where it may lose its electroactivity as that in Nafion. The interfused CNT could act as electronic wires that connect the electrode with Ru(bpy)(3)(2+), which made the composite film much more electronically which finally led to the increasing of Ru(bpy)(3)(2+) conductive. Besides, the negatively charged CNT could also absorb some Ru(bpy)(3)(2+). Moreover, the strong electrostatic interaction between AQ and Ru(bpy)(3)(2+) made the composite films much more stable. The combination of AQ and CNT brings excellent sensitivity with the detection limit as low as 3 x 10(-11) M for TPA.

Preparation of magnetic and conductive NiZn ferrite-polyaniline nanocomposites with core-shell structure

Magnetic and conductive NiZn ferrite-polyaniline nanocomposites with novel core-shell structure have been fabricated by microemulsion process. The samples were characterized by XRD, TEM, SEM, IR, UV-vis, voltage/current detector and SQUID magnetometry. The core-shell structure of nanocomposites was observed by TEM. The changes of the magnetic and conductive properties after polyaniline coating were investigated.

A rapid solid-phase synthesis to soluble oligothiophene molecular wires

A novel method for the preparation of oligothiophene molecular wires is described via a bi-directional solid-phase synthesis. Using an alternating sequence of bromination and Stille coupling reactions, oligomers were obtained up to the heptamer in excellent yield and purity.

Metal-containing molecular wires and their electron transportation properties

Metal-containing conjugated bisthioester 1 was synthesized. It was fabricated into "gold electrode - molecular wires monolayers - gold nanoparticles" junction using self-assembly and nanoparticles deposition techniques. The junction is suitable for investigating the electron transportation property of molecular wires.

Conductive hybrids from water-borne conductive polyaniline and (3-glycidoxypropyl)trimethoxysilane

Free-standing conductive films of organic-inorganic hybrids were prepared employing the sol-gel process of (3-glycidoxypropyl)trimethoxysilane (GPTMS) and water-borne conductive polyaniline (cPANI) in water/ethanol solution. The hybrids displayed a percolation threshold for electrical conductivity at a volume fraction of 2.1% polyaniline (PANI); the maximum conductivity of the hybrids reached 0.6 S/cm. GPTMS showed good compatibility with water-borne cPANI during the sol-gel process, and freestanding conductive films were obtained at room temperature. Transmission electron microscopy images of the hybrids indicated that the cPANI was dispersed in the inorganic phase in nanoscale. Because of good confinement of cPANI chains in the inorganic network, water resistance of the hybrid films was significantly improved compared with that of pure cPANI; the electrical conductivity of the films kept stable for 6-7 days soaking in water, whereas it decreased sharply for 1 day soaking for the pure cPANI.

Morphology and thermal properties of conductive polyaniline/polyamide composite films

Polyaniline (PANI) in an emeraldine-base form, synthesized by chemical oxidation polymerization, was doped with camphor sulfonic acid (CSA). The conducting complex (PANI-CSA) and a matrix, polyamide-66, polyamide-11, or polyamide-1010, were dissolved in a mixed solvent, and the blend solution was dropped onto glass and dried for the preparation of PANI/polyamide composite films. The conductivity of the films ranged from 10(-7) to 10(0) S/cm when the weight fraction of PANI-CSA in the matrices changed from 0.01 to 0.09, and the percolation threshold was about 2 wt %. The morphology of the composite films before and after etching was studied with scanning electron microscopy, and the thermal properties of the composite films were monitored with differential scanning calorimetry. The results indicated that the morphology of the blend systems was in a globular form. The addition of PANI-CSA to the films resulted in a decrease in the melting temperature of the composite films and also affected the crystallinity of the blend systems.