5.12 Electrospinning and Polymer Nanofibers: Process Fundamentals

Electrospinning is a popular technique for manufacturing nanofibers using an electrified jet of a polymeric fluid. The fibrous, nonwoven mat that typically results from electrospinning finds applications in a wide range of industries. While setting up an electrospinning experiment is relatively simple, controlling the attributes of the end-products, such as the diameter and morphology of the fiber formed, the orientation of the deposited fiber, the porosity, and the surface properties of the resultant mat, etc., is considerably more challenging. Significant progress has been made in recent years in understanding the physical mechanisms that govern the process of fiber formation through electrospinning. This chapter reviews these advances and provides an overview of the present status of the technology. The process of electrospinning is outlined and the mathematical framework for studying the mechanics involved is discussed. The relevant electrical and the rheological aspects of polymeric fluids are also reviewed. An account of the advances in controlling the fiber diameter, morphology, and surface properties, as well as in controlling the properties of the mat, is provided. This chapter also discusses the limitations of the current technology and provides a perspective for future developments.