Controlling the length of short electrospun polymer nanofibers via the addition of micro-spherical silica particles

Short electrospun nanofibers were fabricated by adding 1.2 µm micro-spherical silica particles with concentrations that varied from 0 to 10 wt% in a 13 wt% polymer solution. The addition of these silica particles resulted in four types of nanofibers: short, short-beaded, short aggregated-beaded, and continuous-beaded. The flow rate to fabricate short nanofibers was increased to 1 µL min⁻¹ by the addition of 1–10 wt% silica particles, compared with the maximum flow rate of a plain polymer solution at 0.48 µL min⁻¹. Short-beaded nanofibers were fabricated at 20 µL min⁻¹ by the addition of 4 wt% silica particles not fabricated from the plain polymer solution. Nanofibers were cut at the edges of the micro silica particles, and the lengths were nearly in inverse proportion to the concentration of the silica particles. The lengths of the short nanofibers calculated by a cutting model, wherein the nanofibers were cut to match the portion of each micro silica particle, were consistent with the experimental results. This indicates that the lengths of short nanofibers can be simply controlled by the number of micro-spherical silica particles.