No abstract

No abstract

No abstract

Sulfonated polyaniline (SPANi), a self-doped conjugated polymer, has received great interest in recent years; however, controlling its shape, size, and conductivity at the nanoscale remains a significant challenge. Here, we report an initiator-assisted route to SPANi nanostructures by rapidly copolymerizing o-aminobenzenesulfonic acid with aniline or its derivatives in the presence of a catalytic amount of the initiator–aniline dimer. UV–vis, FT-IR, and XRD spectra reveal that the chemical compositions of the SPANi nanostructures are similar to that of conventional SPANi possessing an agglomerated morphology. By regulating the comonomer molar ratios, the aniline derivatives used and the acidic media employed, the morphology of the SPANi changes from 1-D nanofibers, nanosticks, nanothorns, and nanorods to 2-D nanoplates and 3-D porous nanospheres. The length and aspect ratio of the SPANi nanofibers can reach values up to 4.5 μm and 60, respectively. These SPANi nanostructures are readily processable in both organic and aqueous solvents and demonstrate 6 orders of magnitude enhanced conductivity at pH values of 5.5–6.0 when compared to conventional polyaniline.

The influence of different types of solvents as sheath fluids on the quality of electrospun ethyl cellulose (EC) nanofibers is investigated in this paper by a modified coaxial process. With 24 w/v % EC in ethanol as electrospinning core fluid and pure solvents including methanol, ethanol and N,N-dimethyl formamide (DMF) as sheath fluids, EC nanofibers were generated by the modified processes. Field emission scanning electron microscope observations demonstrate that the modified process is effective in improving the nanofibers' quality in terms of nanofibers' diameters, distributions and structural uniformity. The key of the modified coaxial process is the reasonable selection of the sheath solvents that is suitable for the drawing process of core EC fluid during the electrpospinning. The EC nanofibers' diameters (D, nm) could be manipulated through the reasonable selection of the type of the sheath solvents based on their boiling point (T, °C) D = 841-3.71T (R= 0.9753). This paper provides useful methods for the implementation of the modified coaxial process controllably to obtain polymer nanofibers with high quality.