Synthesis Of Polyaniline Nanostructures Research Articles

Synthesis of polyaniline nanostructures by electrochemical deposition on niobium

Nanostructured polyaniline films have been electrochemically synthesized on passivated niobium substrate by potentiodynamic method in 0.5 and 1 mol L−1 H2SO4 solution and different aniline/acid molar ratios. The niobium oxide particles formed during passivation induce the nucleation of polyaniline nanofibers via adsorbed phenazine nucleates. The infrared spectra of polyaniline nanofibers showed the presence of vibrations attributed to phenazine-units in the polymer chain which support the phenazine nucleates theory for polyaniline nanofiber growth. The morphology of polyaniline is also influenced by acid concentration and a branched structure consisting of polyaniline nanofibers with a mean diameter of 70 nm is observed for 1 mol L−1 sulfuric acid solution. The shape of the impedance spectra is controlled by charge transport through ion diffusion, with higher diffusion resistances for granular polyaniline. The capacitance increases with the polymer layer thickness and has higher values for nanofibrilar than for granular polyaniline.

A new strategy for the synthesis of polyaniline nanostructures using m-CPBA as an oxidant

In this work, we have reported a unique strategy of using Meta-Chloroperoxybenzoic acid (m-CPBA) as an oxidant for Polyaniline (PANI) nanofibers preparation. A templateless rapid mixing method was employed for chemical polymerization of aniline at room temperature under rapid mixing and without use of additional oxidant. PANI nanofibers were fully characterized and their electrochemical properties have been studied in detail. Further, effects of toluene solution on PANI electrochemical properties were also investigated in detail. The results showed that PANI nanofibers, in the presence of toluene as solvent, had relatively high specific capacitance and high columbic efficiency compared to their bulk solution, which was due to the immobile of toluene solution and the fast diffusion of the H+ ions through the polymer material during the redox process.

Synthesis of polyaniline nanostructures in micellar solutions

AbstractPolymerization of aniline nanoparticles was carried out in aqueous micellar solutions of surfactants, including anionic (sodium dodecyl sulfate), nonionic (nonyl phenol ethoxylate), and cationic (cetyltrimethyl ammonium bromide) surfactants. The size and morphology of these synthesized PANI nanoparticles strongly depended on the structure of the surfactants used in the formation of micelles, as shown by transmission electron microscopy. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction were used in the characterization of the synthesized PANI nanoparticles. The PANI nanoparticles revealed enhanced conductivity compared to conventional bulk PANI. In addition PANI–poly(methyl methacrylate) (PMMA) nanocomposites were synthesized. The results revealed that the PMMA nanoparticles retarded thermal decomposition and enhanced the conductivities compared with pristine PANI nanoparticles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis of PANI nanostructures with various morphologies from fibers to micromats to disks doped with salicylic acid

Shape-controllable polyaniline (PANI) nanostructures varying from fibers to micromats and disks were synthesized via a self-assembly process with salicylic acid (SA) as dopant. It has been achieved just by tuning the concentration of aniline, the mole ratio of SA to aniline, and the mole ratio of APS to aniline in the same reaction. The diameters of the fibers could be controlled from 30 to 400 nm by adjusting the concentration of aniline. Micromats of fibers would be formed by changing the mole ratio of SA to aniline. Disk-like PANI nanostructures were synthesized when decreasing the mole ratio of APS to aniline. Scanning electron microscopy and transmission electron microscopy were applied to investigate various kinds of morphologies. The mechanism of forming these morphologies was proposed to be adjusted by the pH value during polymerization. Ultraviolet–visible (UV–vis) absorption spectra and Raman spectra suggested that these as-prepared PANI were in conductive emeraldine state and featured obviously different molecular structures, which aroused from different reaction conditions.

Synthesis of polyaniline nanostructures in different lamellar liquid crystals and application to lubrication

Polyaniline (PANI) nanostructures were synthesized in lamellar liquid crystal (LLC) formed by different surfactants. It was found that PANI presented lamellar nanostructures by using the template of LLC formed by ionic surfactant of sodium dodecyl sulfonate (SDS) or hexadecyltrimethylammonium bromide (CTAB), whereas PANI spheric nanostructures were obtained within the LLC template formed by the nonionic surfactant of Triton X-100. The formation mechanisms of PANI nanostructures were discussed. Besides, the lubricating effect of PANI in LLC template was also investigated, and the results showed that spheric PANI had better lubricative performance than lamellar PANI.

Synthesis of polyaniline nanostructures with controlled morphology by a two-phase strategy

Polyaniline nanostructures with tubular, spherical, polyhedral, dendritic and belt-like morphologies were synthesized by simply tuning the preparation conditions in a two-phase medium. SEM, FTIR and UV–vis were applied for the characterization of the products. The results showed that the polarity of the organic solvents, the amount of ammonium peroxydisulfate (APS) and the concentration of the acetic acid influenced the morphologies of the polyaniline nanostructures. The difference in the polyaniline morphologies was attributed to the difference in the relative rate of interfacial nucleation to aqueous nucleation. The route reported here is expected to be applied for the controlled synthesis of various polymer nanostructures.