Effect of collector design on the morphological properties of polycaprolactone electrospun fibers

Polycaprolactone (PCL) fibers were produced by electrospinning using three collectors: rotating drum, static copper wires, and a rotating mandrel. The effect of collector design on the alignment and morphology of fibers was evaluated. The drum collector produced a typical tridimensional structure whereby the rotational speed mechanically stretches fibers and affects their diameter and alignment. Randomly oriented fibers with an average diameter of 1142 +/- 391 nm were obtained at 0 rpm, while aligned fibers with an average diameter of 663 +/- 334 nm were produced at 2000 rpm. Static copper wires produced a novel fiber pattern in which the degree of orientation of the fibers is related to the electrical field distribution along the collector. The best fiber alignment and lowest average fiber diameter (490 +/- 131 nm) were obtained using parallel copper wires with a gap of 1 cm. Two main forces influenced the fibers produced by the rotating mandrel. First, the attraction of the electrical field by the collector induced the deposition of fibers parallel to its axis with an average diameter of 606 +/- 329 nm. Second, the stretching force from the high-speed rotation induced the deposition of fused fibers transverse to the collector axis. (C) 2017 Elsevier B.V. All rights reserved.