Electrospinning as a versatile method for fabricating coreshell, hollow and porous nanofibers

Electrospinnng is one of the most conventional methods for producing nano fibers in different forms, such as core-shell hollow and porous nanofibers. These forms open new windows on innovative applications for nanofibers like ultra filtration, fuel cells, membranes, tissue engineering, catalysis and drug delivery or release and nanofluidics and hydrogen storage. In the presented paper, developments in the electrospinning method toward fabrication of core-shell, and hollow and porous nanofibers are presented. Different spinnerets like coaxial and side by side are considered. Furthermore, experienced methods for producing these novel fibers, such as Nonsolvent-Induced Phase Separation (NIPS) and phase separation, are described. It is concluded that there is rapid development and achievement in the improvement of nanofibers for new applications, and electrospinning has become a forerunner in this field.