The effects of solution properties and polyelectrolyte on the electrospinning of poly(ethylene oxide) (PEO) solutions were investigated. Ultrafine PEO fibers without beads were electrospun from 3, 4, 7 and 7 wt% PEO solutions in chloroform, ethanol, (dimethylformamide) DMF and water, respectively. At these concentrations, the values of [eta]C were similar to10 for all solutions. The average diameters of PEO fibers were ranged from 0.36 to 1.96 mum. The higher the dielectric constant of solvent was, the thinner PEO fiber was. The average diameters of electrospun PEO fibers from PEO/water solutions were decreased and their distributions were narrowed by adding 0.1 wt% poly(allylamine hydrochloride) (PAH) and poly(acrylic acid sodium salt) (PAA) due to the increased charge density in solutions. The addition of PAH and PAA lowered the minimum concentration for electrospinning of a PEO/water solution to 6 wt%. (C) 2004 Elsevier Ltd. All rights reserved.