Abstract

Electrospinning has emerged in recent years as a relatively easy, efficient and robust method to make ultrafine continuous fibers with diameter on the order of-100 nm from a variety of materials. As a result, numerous applications for electrospun fibers have already been demonstrated including the commercialized ones in the areas of filtration and tissue engineering. However, in most cases, the nanofibers are homogeneous; the development of external and internal nanostructures could significantly expand the applications of these fibers. The goal of this dissertation is therefore to develop controllable nanostructures for electrospun fibers with an emphasis on the understanding of structure formation and explore their unique applications. Specifically, this dissertation can be divided into two areas. The first part is related to superhydrophobic or "self-cleaning " surfaces. This has been a hot research area due to the wide applications of such materials. Electrospun fibers were first discovered in this dissertation to have sufficient surface roughness for superhydrophobic effect. In