Electrostatic fabrication of ultrafine conducting fibers: polyaniline/polyethylene oxide blends

Ultrafine fibers of polyaniline doped with camphorsulfonic acid (PAn.HCSA) blended with polyethylene oxide (PEO) were prepared by a non-mechanical, electrostatic spinning (“electrospinning”) technique. The morphology and fiber diameter of electrospun polyaniline blend fibers revealed that both the PEO and the PAn.HCSA/PEO blend fibers had a diameter ranging between 950 nm and 2.1 μm, with a generally uniform thickness along the fiber. The UV–visible spectra of these electrospun fibers were similar to those for cast films produced from the same solutions. As expected, the conductivity of the non-woven fiber mat, as measured by the four-point probe method, was slightly lower than that of a cast film, due to the high porosity of the non-woven mat. The rate for the vapor phase de-doping/re-doping of the electrospun fibers is at least one order of magnitude faster than for cast films, stressing the enormous effect an increase in the surface-to-volume ratio, accomplished by electrospinning the material into fibers, can have on the selected chemical properties of polyaniline blends.