The Formation of Oligoaniline Microspheres in Alkaline Media

Aniline oligomers are generally believed to be responsible for the self-assembly that guides the growth of polyaniline nanostructures. The oxidations of aniline with ammonium peroxydisulfate, which are started and finished above pH 2.5, produce aniline oligomers only. Under alkaline conditions, oligoaniline microspheres spheres are formed as the dominating morphology. They will be potentially useful in applications that do not require conductivity, such as in electrorheology, corrosion protection, as ionic conductors or catalyst supports. Aniline oligomers prepared at alkaline conditions as microspheres have been studied by UV–Vis, infrared and Raman spectroscopies in the combination with optical and electron microscopic techniques. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3483

The Flower-Like Hierarchical Architectures Assembled from Aniline Oligomers

The flower-like hierarchical architectures assembled from aniline oligomers by a template-free method are reported. They are important because of their close relation to a conducting polymer, polyaniline. Their formation process is ascribed to the self-assembly of oligoanilines under non-covalent interactions, such as hydrogen bonding, hydrophobic forces, and π–π stacking. The model of directional growth is offered to explain the formation of petal-like objects and, subsequently, flowers. In order to investigate the chemical structure of the oligomers, a series of characterizations have been carried out, such as UV–visible, Fourier-transform infrared and Raman spectroscopies. Based on the results of characterization methods, a formation mechanism of the aniline oligomers and their self-assembly are proposed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3484

Electrical Conductivity of Electrospun Polyaniline and Polyaniline-Blend Fibers and Mats

Submicrometer fibers of polyaniline (PAni) doped with (+)-camphor-10-sulfonic acid (HCSA) and blended with poly(methyl methacrylate) (PMMA) or poly(ethylene oxide) were electrospun over a range of compositions. Continuous, pure PAni fibers doped with HCSA were also produced by coaxial electrospinning and subsequent removal of the PMMA shell polymer. The electrical conductivities of both the fibers and the mats were characterized. The electrical conductivities of the fibers were found to increase exponentially with the weight percent of doped PAni in the fibers, with values as high as 50 ± 30 S/cm for as-electrospun fibers of 100% doped PAni and as high as 130 ± 40 S/cm upon further solid state drawing. These high electrical conductivities are attributed to the enhanced molecular orientation arising from extensional deformation in the electrospinning process and afterward during solid state drawing. A model is proposed that permits the calculation of mat conductivity as a function of fiber conductivity, mat porosity, and fiber orientation distribution; the results agree quantitatively with the independently measured mat conductivities.United States. Army Research Office (Institute for Soldier Nanotechnologies, Contract ARO W911NF-07-D- 0004