Conducting Polyaniline Nanowires Research Articles

Polyaniline nanowires aligned on MOFs-derived nanoporous carbon as high-performance electrodes for supercapacitor

Polyaniline, as the pseudocapacitive electrode material, has been extensively studied for supercapacitors. However, their cycling stability is limited by the structural instability arising from large volumetric swelling/shrinking, which has been the main obstacle to their practical applications. Herein, this work reports metal organic frameworks(MOFs)-derived porous carbon frameworks as the substrate and further deposit polyaniline by in situ chemical polymerization. Benefit from the structurally stable MOFs-derived porous carbon frameworks and the uniformly-deposited conducting polyaniline nanowires with controlled lengths, the synthesized MOFs-derived porous carbon/polyaniline hybrid electrode displays a maximum specific capacitance of 534.16 F g−1 at 0.2 A g−1 and a maximum capacitance retention of 211% at 2 A g−1 after 20000 cycles, demonstrating promising applications for pseudocapacitive devices. The assembled semi-solid symmetrical supercapacitors delivers good electrochemical performance (energy density of 9.72 μWh cm−2) and excellent cyclic stability (94.4% at 10000 cycles), which can also power a commercial LED.

Enhanced photoluminescence from gold nanoparticle decorated polyaniline nanowire bundles

Enhanced emission is observed from a nanocomposite consisting of conducting polyaniline nanowire bundles decorated with gold nanoparticles synthesized by simple physical blending and in situ interfacial polymerization techniques.

Conducting Polyaniline Nanowire Arrays Modified Electrode for High Performance Supercapacitor and Enhanced Catalysis of Nitrite Reduction

AbstractVertically aligned conducting polymer nanowire arrays had great potential applications in supercapacitor electrode material and exhibited enhanced electrocatalytic behavior towards the reduction of nitrite. In this paper, a facial template‐free approach to synthesize large arrays of vertically aligned polyaniline (PANI) nanowires on electrochemically pretreated glassy carbon electrodes was reported by using a galvanostatic current method. The as‐prepared large arrays of PANI nanowires had very narrow diameters and were oriented perpendicular to the substrate, which was a benefit to the ion diffusion when being used as the supercapacitor electrode. The highest specific capacitance of PANI nanowire arrays was measured and kept high at a large charge‐discharge current density. Furthermore, it also can detect nitrite with ultrahigh sensitivity of 62.99 µA mM−1 cm−2 and a remarkable fast response time of less 1 s. The results indicated that the vertically aligned PANI nanowires could dramatically enhance the electrochemical performance.

Gold nanoparticles and polyethylene glycols functionalized conducting polyaniline nanowires for ultrasensitive and low fouling immunosensing of alpha-fetoprotein

An ultrasensitive biosensor for alpha-fetoprotein was developed based on electrochemically synthesized polyaniline (PANI) nanowires, which were functionalized with gold nanoparticles (AuNPs) and polyethylene glycols (PEG). The prepared PEG/AuNPs/PANI composite, combining the electrical conductivity of the AuNPs/PANI with the robust antifouling ability of PEG, offered an ideal substrate for the development of low fouling electrochemical biosensors. Alpha-fetoprotein (AFP), a well-known hepatocellular carcinoma biomarker, was used as a model analyte, and its antibody was immobilized on the PEG/AuNPs/PANI for the construction of the AFP immunosensor. Using the redox current of PANI as the sensing signal, in addition to the good biocompatibility of PEG/AuNPs and the anti-biofouling property of PEG, the developed immunosensor showed improved biosensing performances, such as wide linear range and ultralow detection limit (0.007pgmL−1). More importantly, it is label-free, reagentless and low fouling, making it capable of assaying AFP in real serum samples without suffering from significant interference or biofouling.

Electrodeposited Conducting Polyaniline Nanowire Arrays Aligned on Carbon Nanotubes Network for High Performance Supercapacitors and Sensors

Conducting polymer polyaniline (PANI) nanowire arrays were electrochemically in situ synthesized on the surface of glassy carbon electrodes, which were modified with self-assembled multi-walled carbon nanotubes (CNTs) networks. The ordered PANI nanowire arrays and CNTs networks were integrated to create 3D nanostructured PANI/CNTs composites. Owing to their unique microstructure and conductivity, the PANI/CNTs nanocomposite exhibited excellent electrical properties such as remarkable supercapacitor performance and catalytic activity toward nitrite electrochemical reduction. It was found that the PANI/CNTs nanocomposite was capable of delivering high specific capacitance and showed excellent cycling stability. Moreover, it could be utilized as an electrochemical sensor for the detection of nitrite, with an outstanding sensitivity, low detection limit (6.1μM, a signal to noise ratio of 3) and a fast response time of less than 5s.

Conducting polyaniline nanowire electrode junction

In this paper, a synthesis of conducting polyaniline nanowires electrode junction (CPNEJ) has been reported. Conducting polyaniline nanowires electrode junction on Si / SiO 2 substrate (having 3 μm gap between two gold microelectrodes) is prepared. Polyaniline nanowires with diameter (ca. 140 nm to 160 nm) were synthesized by one step electrochemical polymerization using galvanostatic (constant current) technique to bridge this gap. The surface morphology of CPNEJ was studied by scanning electron microscope (SEM). The synthesized CPNEJ is an excellent platform for biosensor applications.

Glucose sensor based on conducting polyaniline nanowire electrode junction

In the present investigation, a glucose sensor based on conducting polyaniline nanowire electrode junction (CPNEJ) has been reported. The CPNEJ platform was modified by glucose oxidase by cross-linking in the presence of glutaraldehyde. The signal transduction mechanism of the sensor is based on the change in micro electrode junction conductance as a result of glucose oxidation induced change in the polymer redox state. Small size of CPNEJ sensor causes to regenerate enzyme naturally without need of redox mediators, as a result it consumes minimum amount of oxygen and also gives very fast response. This sensor exhibited good linear response range from 1 mM to 20 mM of glucose concentration with excellent sensitivity of 12 μA/mM.

Conducting core-shell nanowires by amyloid nanofiber templated polymerization.

The preparation of conducting polymer nanowires in aqueous solutions is a challenging goal, especially for applications in nanobioelectronics. Here, we show that amyloid nanofibers template the formation of conducting polyaniline nanowires with a core-shell architecture. The nanofibers exhibit hydrophobic pockets that presumably preassemble the aniline monomers. The template directs polymer morphology as it favors the formation of linear polymer chains, suppresses defects in the polymer chain which are detrimental to charge transport and induces chiral helicity into the polymer. This strategy has the potential of being applied to other polymers than polyaniline and might open up new possibilities to synthesize biocompatible and conducting polymer nanowires with prospects for applications in, for example, sensing, neuronal tissue engineering, and electrostimulated stem cell differentiation.

Thread-like supercapacitors based on one-step spun nanocomposite yarns.

Thread-like electronic devices have attracted great interest because of their potential applications in wearable electronics. To produce high-performance, thread-like supercapacitors, a mixture of stable dispersions of single-walled carbon nanotubes and conducting polyaniline nanowires are prepared. Then, the mixture is spun into flexible yarns with a polyvinyl alcohol outer sheath by a one-step spinning process. The composite yarns show excellent mechanical properties and high electrical conductivities after sufficient washing to remove surfactants. After applying a further coating layer of gel electrolyte, two flexible yarns are twisted together to form a thread-like supercapacitor. The supercapacitor based on these two yarns (SWCNTs and PAniNWs) possesses a much higher specific capacitance than that based only on pure SWCNTs yarns, making it an ideal energy-storage device for wearable electronics.

Conducting Polymer Nanowire Arrays for High Performance Supercapacitors

This Review provides a brief summary of the most recent research developments in the fabrication and application of one-dimensional ordered conducting polymers nanostructure (especially nanowire arrays) and their composites as electrodes for supercapacitors. By controlling the nucleation and growth process of polymerization, aligned conducting polymer nanowire arrays and their composites with nano-carbon materials can be prepared by employing in situ chemical polymerization or electrochemical polymerization without a template. This kind of nanostructure (such as polypyrrole and polyaniline nanowire arrays) possesses high capacitance, superior rate capability ascribed to large electrochemical surface, and an optimal ion diffusion path in the ordered nanowire structure, which is proved to be an ideal electrode material for high performance supercapacitors. Furthermore, flexible, micro-scale, threadlike, and multifunctional supercapacitors are introduced based on conducting polyaniline nanowire arrays and their composites. These prototypes of supercapacitors utilize the high flexibility, good processability, and large capacitance of conducting polymers, which efficiently extend the usage of supercapacitors in various situations, and even for a complicated integration system of different electronic devices.

Conducting Polyaniline Nanowire and Its Applications in Chemiresistive Sensing.

One dimensional polyaniline nanowire is an electrically conducting polymer that can be used as an active layer for sensors whose conductivity change can be used to detect chemical or biological species. In this review, the basic properties of polyaniline nanowires including chemical structures, redox chemistry, and method of synthesis are discussed. A comprehensive literature survey on chemiresistive/conductometric sensors based on polyaniline nanowires is presented and recent developments in polyaniline nanowire-based sensors are summarized. Finally, the current limitations and the future prospect of polyaniline nanowires are discussed.

Hybrid composites of short acetylated kenaf bast fiber and conducting polyaniline nanowires in epoxy resin

This article reports the preparation and characterization of newly developed hybrid composites consisting of epoxy resin (EP) matrix, acetylated kenaf bast fiber (AKF) and conducting polyaniline (PANI) nanowires. Initially, the EP/AKF composites were prepared by varying the AKF loading (5–30 wt%). The EP/AKF displayed an optimum tensile strength at 20 wt% AKF loading which was higher than that of untreated kenaf fiber EP composites (EP/UKF). The hybrid composites of EP/AKF/PANI were then prepared by using 20 wt% AKF loading with PANI inclusions from 2 to 14 wt%. The addition of PANI into EP/AKF induced positive electrical properties without considerably sacrificing its mechanical integrity. It was found that the electrical percolation threshold of these hybrid composites was at 11 wt% of PANI loading. PANI inclusions at above the percolation loading resulted in reduction of tensile and flexural strength. Meanwhile, no significant mechanical loss was observed below the threshold. The fracture morphological analysis revealed the occurrences of PANI nanowires pull out from the matrix. The Fourier transform infrared spectroscopy showed that the PANI component still maintained its doped condition inside the EP/20AKF. Water absorption and thermal analysis indicate that the PANI incorporation induced lower water uptakes and greater thermal stability to the EP/20AKF, respectively.

ELECTRICALLY CONDUCTIVE NANOCOMPOSITES OF EPOXY/POLYANILINE NANOWIRES DOPED WITH FORMIC ACID: EFFECT OF LOADING ON THE CONDUCTION AND MECHANICAL PROPERTIES

This paper reports the preparation and characterization of nanocomposites consisting of epoxy resin (EP) and conducting polyaniline nanowires doped with formic acid (PANI-FA). The percolation threshold of this nanocomposites was obtained at 8 wt.% of PANI-FA loading. On the other hand, 8 wt.% of PANI-FA resulted in reduction of tensile and flexural modulus up to 30% and 16%, respectively. The fracture morphological analysis revealed a distinct PANI-FA domain on the EP matrix after the percolation threshold has been reached. Using the scaling law of the percolation theory, it was found that the conductivity of the nanocomposites exhibited an exponential factor, (t) of 0.417.

Conducting Polyaniline Nanowire Arrays for High Performance Supercapacitors

Vertically aligned conducting polymer nanowire arrays have great potential applications in supercapacitor electrode materials. In this paper, we report a facial one-step template-free approach to synthesize large arrays of vertically aligned polyaniline (PANI) nanowires on various conducting substrates by using a galvanostatic current method. The as-prepared large arrays of PANI nanowires had very narrow diameters and were oriented perpendicular to the substrate, which was a benefit to the ion diffusion when being used as the supercapacitor electrode. The highest specific capacitance of PANI nanowire arrays was measured as 950 F·g−1 and kept as high as 780 F·g−1 at a large charge−discharge current density (40 A·g−1). Furthermore, the capacitances in several different electrolytes, including HClO4, lithium bis(trifluoromethane sulfonyl) (LiTFSI) aqueous solution and nonsolvent electrolyte ionic liquid, were investigated. The results indicated that the orientation of nanostructures could dramatically enhanc...

Electronic transport characteristics of electrolyte-gated conducting polyaniline nanowire field-effect transistors

We investigate the electronic transport characteristics of an electrolyte-gated conducting polyaniline (PANI) nanowire field-effect transistor (FET) assembled between two Au electrodes on SiO2/Si substrate using nanochannel-assisted chemical oxidative polymerization. This is the first demonstration that the current-voltage characteristics for a PANI nanowire FET exhibit significant hysteresis, which is typically greater on the positive sweep of the potential than on the negative sweep. We suggest that this hysteresis is due to changes in the PANI structure and the effects of Coulombic repulsion in PANI nanowires on oxidation process. We also present degradation properties of PANI nanowire FETs with electrochemical gate potential.

Conductance of a Single Conducting Polyaniline Nanowire

Conductance of a Single Conducting Polyaniline Nanowire