Core-Shell Nanofibers: Nano Channel and Capsule by Coaxial Electrospinning

In the last 30 years, nano science and technology have an unprecedented development. Nanofibers, one-dimensional (1D) nanostructures have been paid great attentions due to their unique properties and intriguing applications in many areas (Xia et al., 2003). In lots of synthetic and fabrication methods, electrospinning (a drawing process based on electrostatic interactions) provided the simplest approach to nanofibers with exceptionally long in length, uniform in shape, and diversified in composition (Li et al., 2004; Greiner et al., 2007). Following the fast and polymer common property, scientists invented complex electrospinning. Utilizing electrostatic interactions and through the elongation of viscoelastic jet device, electrospinning technique can copy the structure of jet device to nanoscale fibers from polymer solution or molten. Various nanofibers with different secondary nanostructure were fabricated. Especially, core-shell nanofibers pull more and more interesting and attention, because of the great potential applications and prospects for nanochannel, nanocapsule and small encapsulating devices. Coaxial electrospinning is an effective, fast and controlled technique to construct core-shell nanostructures into nanofibers (Li et al, 2004; Zhang et al., 2004 and Xia et al., 2006). Here, based on complex electrospinning technique, we will describe nanofibers with nanochannel and core-shell nano-capsule fabrication, and how coaxial electrospinning is working to construct various nanostructures in the nanofibers. Furthermore, we will introduce some encapsulation of stimulating responsive materials into core-shell nanofibers, and the improvement of the responsibility and functional devices applications for the combination of core-shell nanofibers and stimulating responsive materials.