Effect of ionic salts on the processing of poly(2-acrylamido-2-methyl-1-propane sulfonic acid) nanofibers



We studied the effect of nanofiber uniformity on electrospinning due to the charging of added ionic salts, as compared to the droplet current nonadded ionic salts and the charge-to-mass ratio of a highly conducting liquid. Various ionic salt concentrations were investigated. For an ionic salt concentration of 0.01 mol %, an applied electric field of 15 kV, and a spinning distance of 15 cm, the experimental results show that uniform nanofibers that did not contain any beads were synthesized with an optimal ionic salt concentration, when the convective current was two orders of magnitude higher than the nonadded ionic salt droplet current. The obtained fibers were uniform, with diameters of around 70 nm. We were able to produce these uniform nanofibers by controlling the balance between two opposing factors during electrospinning, by increasing the number of charge carriers and decreasing the viscosity of the solution. The effect of the ionic salts on the morphology of the electrospun nanofibers was investigated with field-emission scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1388–1393, 2005