New electrospinning nozzle to reduce jet instability and its application to manufacture of multi-layered nanofibers.

A new nozzle system for the efficient production of multi-layered nanofibers through electrospinning is reported. Developed a decade ago, the commonly used coaxial nozzle system consisting of two concentric cylindrical needles has remained unchanged, despite recent advances in multi-layered, multi-functional nanofibers. Here, we demonstrate a core-cut nozzle system, in which the exit pipe of the core nozzle is removed such that the core fluid can form an envelope inside the shell solution. This configuration effectively improves the coaxial electrospinning behavior of two fluids and significantly reduces the jet instability, which was proved by finite element simulation. The proposed electrospinning nozzle system was then used to fabricate bi- and tri-layered carbon nanofibers.