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, el ectrostatic spinning ("electrospinning") technique. The morphology and fibe r diameter of electrospun polyaniline blend fibers revealed that both the P EO and the PAn.HCSA/PEO blend fibers had a diameter ranging between 950 nm and 2.1 mu m, with a generally uniform thickness along the fiber. The UV-vi sible spectra of these electrospun fibers were similar to those for cast fi lms produced from the same solutions. As expected, the conductivity of the non-woven fiber mat, as measured by the four-point probe method, was slight ly lower than that of a cast film, due to the high porosity of the non-wove n 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, stres sing the enormous effect an increase in the surface-to-volume ratio, accomp lished by electrospinning the material into fibers, can have on the selecte d chemical properties of polyaniline blends. (C) 2000 Elsevier Science S.A. All rights reserved.