Papers by Keyword: Conducting Polymer

Abstract: The synthesis of polyaniline (PANI) doped with anionic spherical polyelectrolyte brushes (ASPB) (PANI/ASPB nanocomposite) by means of in situ chemical oxidative polymerization were presented. The PANI/ASPB nanocomposite was characterized by Fourier trans-form infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive x-ray detector (EDX), and Thermo-gravimetric analysis (TGA). Results showed that PANI/ASPB nanocomposite was successfully fabricated with regular morphology. Investigation of the electrical conductivity at room temperature showed that the electrical conductivity of PANI/ASPB nanocomposite was 9.03 S/cm, which was higher than that of PANI (2.7 S/cm). The measurement of dispersity demonstrated that PANI/ASPB nanocomposite had enhanced dispersity in water.

Abstract: This paper reports the properties of newly developed electrically conductive natural fiber made up of pineapple leaf fiber (PALF) and conducting polyaniline (PANI). The results revealed that the in situ coating of PANI (1 wt.%) showed minimal reduction on the PALF tensile strength. Percolation concentration of the PANI was observed at 5 wt.% and its corresponding electron micrograph showed good polymer deposition with the characteristic globular PANI formation plus no fiber damages. This fiber material has potentials for many applications such as composites, electroactive fillers and conductive sheets.

Abstract: A porous poly (5-cyanoindole) film was easily electrodeposited and for the first time evaluated as an active electrode material in 1.0 M H₂SO₄. The poly (5-cyanoindole) film was investigated using scanning electron microscope, cyclic voltammetry, impedance spectroscopy and charge-discharge test. The specific capacitance of poly (5-cyanoindole) electrode was 336 F g^-1 under the current density of 2.4 A g^-1 and decreased by 30% after 1000 cycles, which indicated that poly (5-cyanoindole) electrode had good cycle stability. Additionally, the specific energy of poly (5-cyanoindole) electrode reached 23 Wh kg^-1 when the specific power was 190 W kg^-1. These results indicated the feasibility of poly (5-cyanoindole) as electrode material for supercapacitors.

Abstract: Four novel cross-linked network conjugated poly (methacrylic acid) functionalized poly (9-aminofluorene) films were prepared by a precursor polymer approach, i.e., poly { poly [ N - (9H-fluoren-9-yl) methacrylamide ] } (P1), poly { poly [ N - (9H-fluoren-9-yl) methacrylamide-co-methacrylic acid ] } (P3), poly { poly [ N - (9H-fluoren-9-yl) methacrylamide] -co-9-aminofluorene } (P2) and poly { poly [ N - (9H-fluoren-9-yl) methacrylamide-co-methacrylic acid ] -co-9-aminofluorene } (P4). As-prepared polymer films had good redox activity and structure stability in concentrated sulfuric acid. Fluorescence spectra indicated that the soluble cross-linked polymers were good blue light emitters and in solid state they were blue-green light emitters.

Abstract: Novel poly (selenophene-co-3-methylthiophene) was successfully achieved by directly electrochemical oxidation of the monomer mixtures of selenophene and 3-methylthiophene (3MeT) in boron trifluoride diethyl etherate. The effect of monomer concentration ratios on the copolymerization were investigated by cyclic voltammetry. The structures of as-prepared copolymers were characterized by UV-vis and infrared spectroscopy. The conductivity and thermoelectric measurements revealed the incorporation of 3MeT into the polyselenophene (PSe) chain improved significantly the conductivity and thermoelectric property of PSe.

Abstract: Polyaniline nanofibers were prepared chemically in both emiraldine base (EB) and emiraldine salt (ES) forms. The composite of polyaniline emiraldine salt with single walled carbon nanotubes (SWCNTs) was developed. Electrochemical sensors based on polyaniline nanofibers and its composite have been developed for the detection of chloropyrifos. Chloropyrifos exhibits one well defined reduction peak. The maximum peak current was linearly related to chloropyrifos concentration in the range from 0.2 μM to 1.4 μM. It was found that the SWCNTs improved the sensitivity of the polyaniline base graphite electrode from 3.0 mA/μM for polyaniline base to 9.69 mA/μM for ES-SWCNTs composite electrode.

Abstract: Polyaniline nanofibers of varying morphology were synthesized using two different chemical methods. The polyaniline samples were prepared through the oxidation of aniline in an ice bath. In the first method, the oxidant is added drop wise in aniline solution whereas in other the samples were prepared via rapid mixing of oxidant into aniline solution. The structural and morphological analysis of prepared samples was carried out using XRD, FTIR and FESEM techniques. The thick films of the synthesized powder were deposited on alumina substrate and their sensing response to various volatile gases was investigated at room temperature. The morphology of synthesized polyaniline powder depends upon method of synthesis and thus effect the sensing response and selectivity of the fabricated sensor.

Abstract: Functional floating bead (F-FB), prepared by anchoring the organic sulfonic acid on the surface of the blackberry-like structural FB, was used as both the inorganic substrate and the in situ dopant for the in situ chemical oxidative polymerization of pyrrole to obtain the plypyrrole/functional floating bead (PPy/F-FB) nanocomposite material. The composites possess high electrical conductivity at room temperature. Thermogravimetric analysis shows that the thermal stability of PPy/F-FB composites was enhanced and these can be attributed to the retardation effect of sulfonic acid-functionalized FB as barriers for the degradation of PPy. The morphology of PPy/FB composites showed the well-defined blackberry-like morphology.

Abstract: An electronic nose based on chemiresistors employing conducting polymers as the sensing material was developed for the discrimination of medicinal plants. The conducting polymers were synthesized through potentiostatic electropolymerization and deposited between two gold wires set 200 μm apart on a Teflon substrate. The polymers were doped with several counter ions. The resistance of the doped polymers changed upon exposure to the headspace of of finely-chopped leaves of the following medicinal plants: Vitex negundo (Lagundi), Mentha arvensis (Yerba Buena), Mentha piperita (Peppermint), Artemisia dracunculus (Taraggon), Blumea balsafimera (Sambong), and Plectranthus amboinicus (Cuban Oregano). The different plant samples yielded distinct responses from the sensor array. The results were subjected to pattern recognition techniques, such as radar plots, principal component analysis (PCA) and dendrogram analysis (DA). PCA showed good discrimination among plant samples. DA confirmed the observed clustering in PCA.

Abstract: Soft conductive elastomer materials have wide potential applications in material science and electronic engineering. Through electrospinning and in-situ polymerization, a kind of well-organized coaxial polyaniline/polyvinylidence fluoride (PANI/PVDF) microfibers with conductivity about 0.6 S/cm were fabricated, which combined the advantages of conducting polymer and elastic material. It is found that the resistance of the fibers was changed with the curvature variation. The results indicate that the PANI/PVDF microfibers could be used as strain sensor with high flexibility, high sensitivity, and stable repeatability.