Distance Between the Needle Tip and Collector

The diameter of the fibers increases as the distance between the needle and the collector is lowered. If it is too short, beaded morphologies can occur due to inadequate fiber drying [4].

Environmental Factors (Humidity and Temperature)

Besides the solution and electrospinning parameters, environmental factors such as relative humidity and temperature also affect the morphology and diameter of the fibers through the solidification process. However, this effect is generally rather limited compared with other parameters. The fiber diameter is usually decreased with the increase of temperature causing lower viscosity of the polymer solutions. Small pores on the surface of the fibers in addition to the beaded fibers maybe generated due to the higher humidity.

Collector Types

Type of collector is another important aspect in the electrospinning process. Usually, aluminum collectors are selected in the electrospinning process. However, difficulty in transferring collected fibers coupled with the need for aligned fibers necessitates other collectors such as conductive paper/cloth or rotating wheel. Due to diminished conductive area, beaded fibers are produced due to decreased surface area. The alignment of fiber is determined by the type of the collector and rotation speed [4].