Preparation Of Self-crimped And Helical Structure Nanofibers

Self-crimp fibers behavior or helix action exists widely in natural materials such as wool, cotton, and proteins. It endows natural fibers with strong flexibility and high porosity. In order to reproduce the excellent characters of natural fibers in synthetic materials, people began to imitate the process in nature fibers to fabricate self-crimp fibers. In the early 1960s, DuPont (Wilmington, DE) synthesized the first self-crimp yarn (PP). Several decades past, self-crimp yarns have been produced vastly in the fiber industry. Nevertheless, the self-crimp of yarns produced in industry is not at nanoscale. Nowadays, people are in need of smaller and more sophisticated materials, the demand of nanomaterials in the market is likely to be immense. Micro- and nanoscale helical structures have been drawing great attention because they have potential applications in many areas, such as structural or inductive components in microelectromechanical systems devices, drug delivery systems, and advanced optical components. However, so far, there is no general method for generating helical structures at micro- or nanoscale.In order to get self-crimped structure nanofibers, we exploited two methords to fabricate these helical fibers. One is side-by-side electrospinning, the other is two-spinneret electrospinning. Self-crimped nanofibers were successful obtained by our new apparatus.In the first portion, uniform helical structures with microscale coil diameter were obtained by side-by-side electrospun, and the existence of a side-by-side bicomponent fiber on morphology was evidenced via SEM. The drawbacks of such method was also investigated. To solve this problem, in the next portion the other methord, two-spinneret electrspinning, was put forward. Our experiment indicated that two-spinnerets electrospinning can succeeful prevent gel formation or precipitation of the polymer, can also fabricate 3D self-crimped nanofibers.