Controlling the morphologies of electrospun nanofibres

Electrospinning is a unique method of producing continuous polymer fibers. It has received a great deal of attention in recent times due to its versatility in the spinning of a wide variety of polymeric fibers and its consistency in producing polymer fibers with the fiber diameter on submicrometer or nanometer scales. The electrospun nanofibers usually have a regular threadlike structure and some fibers can form a ribbon-like fibrous morphology. The fiber diameter varies in range from 5 nm to 10μm. Defectives such as colloid beads or beads-on-string fibers occur among the resultant fibers or even as the major product, depending on the operating conditions and the material properties. The production of nanofibers in a controlled manner, so that the process gives a high-quality fiber with precise fiber morphology, is a vital task, as the fiber morphology has a significant influence on the fiber performance. The control of fiber morphology has been based on a thorough understanding of the electrospinning process and the factors that affect the electrospinning process and the fiber morphologies. The fiber alignment is controlled through the fiber deposition process and the bicomponent nanofibers are electrospun using special spinnerets. This chapter discusses the techniques on controlling the fiber morphology, the fiber orientation, the fiber component, and the web morphology during the electrospinning process.