Design of Porous, Core-Shell, and Hollow Nanofibers

Abstract

Electrospinning can be used to prepare various organic or inorganic nanofibrous structures. These structures could be related to the nanofibers arrangement relative to each other, as random, aligned, 3D, and yarn, or they could be related to the single nanofiber structure and morphology, or both. In the electrospinning process, nanofibers could be produced to have surface or internal porous structure. Considering the type of material which is used, different methods are introduced to get the desired porosity in nanofibers such as chemical etching, blend solution, effect of humidity, and different post-treatment methods. Also, by using different methods, it is possible to produce core-shell nanofibers or hollow ones. For fabrication of the core-shell nanofibers, one method is to use the special coaxial nozzle. However, there are other techniques to get core-shell nanofibers like emulsion precursor solution, different methods of surface coating, and so on. Based on the diversity of techniques, in this chapter an attempt is made to cover the most usable methods to get the porous, core-shell, and hollow nanofibers and present some applications for each.