Synthesis and Investigations of Structural, Optical and AC Conductivity Properties of PANI/CeO2 Nanocomposites

This paper explains the details on the preparation of polyaniline/CeO2 (10 wt %) nanocomposites using the method of in situ polymerization. The formation of PANI/CeO2 nanocomposites were proposed via oxidation of aniline and reduction of CeO2, respectively. The effect of CeO2 concentration on AC conductivity, morphological, optical and structural properties of the prepared PANI/CeO2 nanocomposites material were examined. The structural studies show the presence of CeO2 nanoparticles were occurred in PANI of nanocomposites. The average grain size of PANI/CeO2 nanocomposites varied with increasing and decreasing concentration due to the process of nucleation during the polymerization. The average particle grain sizes were measured from HRTEM. The morphology analysis was carried out from SEM. The UV absorption spectrum showed that the absorption peak of CeO2 nanoparticle at 341 nm, shifted to lower wavelength side, the nanocomposite absorption peaks at about 324, 368 and 858 nm was confirmed by the formation of PANI/CeO2 nanocomposites. The electronic structure of the band gap of the nanocomposite materials were calculated using ultraviolet visible absorption spectrum. The band gap energy of nanocomposite is 3.36 eV. The FTIR spectrum clearly showed the strong presence of CeO2 nanoparticles in PANI chain. The AC conductivity varied with varying the temperature and depends on the concentration due to the formation of PANI/CeO2 nanocomposite.

Sodium dodecylbenzene sulfonate-assisted synthesis of a carbon-cloth-based polyaniline flexible material for supercapacitors

(A and B) Mechanism of SDBS with different concentrations on the PANI chain, (C and D) impact of SDBS on the formation of granular PANI.

Preparation of polyaniline (PANI)-coated Fe3O4 microsphere chains and PANI chain-like hollow spheres without using surfactants

Polyaniline (PANI)-coated Fe3O4 microspheres chains and PANI chain-like hollow spheres are successfully prepared without using surfactants.

Synthesis, Characterisation, and Conductive Superparamagnetism Studies of γ-Fe2O3/Polyaniline-Levodopa Composites

γ-Fe2O3/polyaniline–levodopa (γ-Fe2O3/PANI–levodopa) composites were prepared using γ-Fe2O3 and levodopa as dopants and ammonium persulfate as oxidant. The composites were characterised by Fourier transform infrared spectra and confirmed that the γ-Fe2O3 and levodopa were doped into the PANI chain. A transmission electron microscopy study revealed that the size of the γ-Fe2O3 was of the order of 10 nm, whereas the composite size was of the order of 25 nm; furthermore, it was observed that the PANI–levodopa chain was intercalated to form a core shell of γ-Fe2O3. Cyclic voltammetry and magnetisation studies showed that the γ-Fe2O3/PANI–levodopa composites had both electrochemical activity and conductive superparamagnetism, so these composites may be well suited for chemotherapy drugs.

Water-Based Polyaniline/Montmorillonite/Epoxy Composite Coatings for the Corrosion Protection of Mild Steel

Polystyrene sulfonic acid (PSSA) doped water-dispersible polyaniline (PANI) /montmorillonite (MMT) clay composites were firstly synthesized by intercalation polymerisation in aqueous medium and characterized by XRD and FT-IR. The results showed exfoliated silicate nanolayers of MMT clay dispersed in the PANI matrix and has interaction involving hydrogen bonding between the PSSA-PANI chain and the surface of the MMT clay layer. This composites is more thermal stable than that of without clay samples and results in good stable temperature-dependent dc conductivity [σdc(T)] as temperature changed. The composite anticorrosion coatings of PANI/MMT and waterborne epoxy resin emulsion (EP) were prepared by mixture in aqueous medium and used for corrosion protection of mild steel. Open circuit potential (OCP), Electrochemical impedance spectroscopy (EIS) and Tafel plot demonstrated that the PANI/MMT/EP composite coatings have better anticorrosion properties than PANI/EP, MMT/EP and PANI/MMT/EP mixture. It’s impedance and corrosion potential is higher and the corrosion current density is lower. The anticorrosion coatings are environmental friendly because of water dispersion medium. Introduction

MNDO-PM3 Study of the Early Stages of the Chemical Oxidative Polymerization of Aniline

The theoretical approach to the study of aniline polymerization mechanism has been based on the MNDO-PM3 semi-empirical quantum chemical computations of the heat of formation of aniline dimer and trimer intermediates. The oxidation in aqueous medium without added acid is analyzed. The aniline nitrenium cation is proposed to be the reactive electrophilic species generated by the oxidation of aniline with a two-electron oxidant, ammonium peroxydisulfate, in the initiation phase. 4-Aminodiphenylamine and its fully oxidized form, N-phenyl-1,4-benzoquinonediimine, are the main dimeric products. 2-Aminodiphenylamine and its fully oxidized form, N-phenyl-1,2-benzoquinonediimine, are the most important side products of aniline dimerization. The influence of protonation on the oxidizability of aniline and reaction intermediates was studied. The dominant aniline oligomers have been shown to be linear as well as branched. The importance of reactivity difference between fully oxidized aniline oligomers composed of odd or even numbers of constitutional aniline units is pointed out. The species with odd numbers of aniline units, having nitrenium cationic nature, are much more reactive. The oxidation combined with intramolecular cyclization reaction pathways leads to substituted phenazines, characteristic of two-dimensional PANI chain-growth.