Polyacrylic acid (PAA) is an important Polymer material for metal ion complexation and for nanocomposite materials syntheses. Generating ultrafine, uniform, and stable PAA nanofibers is of great scientific and technological interest for various applications. In this study, we systematically investigated the influence of processing parameters on the morphology and stability of the electrospun ultrafine PAA nanofibers. We show that a higher concentration (up to 25 wt %) favored the formation of uniform PAA nanofibers, whereas at the concentration of 10 wt %, only bead structures were produced. Increasing the applied voltage (up to 22.5 kV) resulted in more uniform PAA nanofibers. In addition, longer collection distance (20 cm) was beneficial for the evaporation of solvent and for decreasing the adhesion between nanofibers, thus leading to the nanofibrous mats with high porosity. Finally, the PAA nanofibers could be rendered water insoluble by heating the electrospun composite PAA/polyvinyl alcohol (PVA) nanofibers at 145 degrees C for 30 min. The resulting nanofibrous mats exhibited excellent performance to remove Cu(II) ions in aqueous solution. The formed nanofibers may find various applications in ultrafiltration, separation, and environmental sciences. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 2409-2417, 2010