Direct microscopic observation of shish-kebab structure in high-temperature electrospun iPP fibers

• iPP fibers containing nano-fibrils are fabricated by high-temperature electrospinning.
• Electrospun iPP fibers consist of shish-kebab structure.
• Elongational force is responsible for the development of shish-kebab structure.

Electrospinning is not only a technique to fabricate macroscopic fiber but also a method to control the microstructure. In this study, high-temperature solution electrospinning was used to prepare isotactic polypropylene (iPP) fibers. Scanning electron microscope (SEM) observation indicates that a single electrospun iPP fiber consists of many nano-fibrils. Based on SEM observation, these nano-fibrils are shish-kebab structure. Electrostatic elongational force involved in the electrospinning process is considered to be responsible for the development of shish-kebab structure.