Anthony L. Andrady Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA
Zeynep Aytac Department of Environmental Health Harvard T.H. Chan School of Public Health Center for Nanotechnology and Nanotoxicology Harvard University Boston, MA, 02115 USA
Jessica L. Barlow Department of Chemical and Life Science Engineering Virginia Commonwealth University Richmond, VA USA
Emily Diep Department of Chemical Engineering University of Massachusetts Amherst Amherst, MA USA
Caitlin Dillard Boeing 1 S Stewart Ave, Ridley Park Philadelphia, PA, 19078 USA
Arzan C. Dotivala Department of Chemical and Life Science Engineering Virginia Commonwealth University Richmond, VA USA
David S. Ensor Retired ISO Technical Committee 209 Cleanrooms and Associated Controlled Environments Spokane, WA USA
Nataliya Fedorova The Nonwovens Institute NC State University Raleigh, NC USA
Yeqian Ge Wilson College of Textiles North Carolina State University Fiber and Science Program Raleigh, NC USA
Vibha Kalra Department of Chemical and Biological Engineering Drexel University Philadelphia, PA USA
Saad A. Khan Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA
Irene S. Kurtz Department of Chemical Engineering University of Massachusetts Amherst Amherst, MA USA
Shani L. Levit Department of Chemical and Life Science Engineering Virginia Commonwealth University Richmond, VA USA
Benoit Maze The Nonwovens Institute NC State University Raleigh, NC USA
Bharadwaja S.T. Peddinti Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA
Tahira Pirzada Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA
Behnam Pourdeyhimi The Nonwovens Institute NC State University Raleigh, NC USA
Vahid Rahmanian Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA
Kristen E. Roskov Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA and BASF Agricultural Solutions BASF Corporation Research Triangle Park, NC USA
Jessica D. Schiffman Department of Chemical Engineering University of Massachusetts Amherst Amherst, MA USA
Richard J. Spontak Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA and Department of Materials Science and Engineering North Carolina State University Raleigh, NC USA
Xiaoyu Sun Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh, NC USA and Integrated Diagnostic Solutions Becton Dickinson & Company Franklin Lakes, NJ USA
Kathleen F. Swana U.S. Army Combat Capabilities Development Command Soldier Center Natick, MA USA
Christina Tang Department of Chemical and Life Science Engineering Virginia Commonwealth University Richmond, VA USA
Breland T. Thornton Department of Chemical and Life Science Engineering Virginia Commonwealth University Richmond, VA USA
Tamer Uyar Department of Fiber Science & Apparel Design College of Human Ecology Cornell University Ithaca, NY, 14853 USA
Howard J. Walls Aerosol Control Group Lead Technology Advancement & Commercialization RTI International Research Triangle Park, NC, 27709‐2194 USA
Xiangwu Zhang Wilson College of Textiles North Carolina State University Fiber and Science Program Raleigh, NC USA
Jiadeng Zhu Wilson College of Textiles North Carolina State University Fiber and Science Program Raleigh, NC USA
Preface
The origins of electrospinning technology dates back to the days when Jean‐Antoine Nollett first electrosprayed water with an electric charge generated from a Leyden Jar, back in 1746. But it was not until 1902 that Cooley filed the first patent on electrospinning based on that process. It took yet another half a century before Geoffrey Taylor in 1969 modeled the deformation of a liquid droplet in an electric field as the Taylor's cone. Electrospinning of nanofibers has come a long way since then, thanks to the intensive burst of research since the 1990s when academia got interested in the process. Today, it is a popular and versatile technology with several books published on electrospinning in recent years, including The Science and Technology of Polymer Nanofibers (Wiley 2008) by one of the present editors. Nanofiber science has made impressive advances and recently discovered a myriad of applications for this unique nanomaterial. Most of these developments occurred during the last two to three decades of research; the term “electrospinning” itself came into common use only as recently as 1995. Among the many different routes to fabricating nanofibers, electrospinning remains the most popular because of its simplicity, low‐cost, and scalability. By definition, nanofibers are 1‐D nanomaterials that have diameterd <100 nm. While there is scientific and regulatory agreement on this size range, many research publications as well as some regulatory organizations accommodate an upper limit of a d = 1000 nm. Electrospinning is able to fabricate nanofibers that fall within both size ranges.
The singular property that makes nanofibers so useful is their very high specific surface area. For instance, at a fiber diameter of 500 nm, the surface area per gram of resin can reach a 1000 m2 that is larger than the floor area of two basketball courts. Compared to other nanogeometries such as thin films, this allows for relatively faster interaction of nanofibers with chemicals, particles, or live cells in applications such as chemical sensors, high‐efficiency filters, biomedical scaffolding applications, and faster release of bioactive compounds in controlled‐release applications. Sub‐100 nm nanofibers, such as those of carbon, display unique quantum size effects, obtain exceptional strength, and high conductivity. Spider drag‐line silk1, naturally occurring nanofibers that are ~20 nm in size diameter, display a tensile modulus of 10.6 (GPa) at 25% RH. Optimized nanofibers for specific applications are usually doped with other molecules, coated with an active material or might be a nanofilled composite material. Also, electrospun fiber mats allow easy handling of the nanofibers in different application and their high porosity helps easier access of reactants to fiber surface functionalities. Industrially relevant nanofiber materials fall into four broad classes: (i) carbon nanofibers; (ii) polymer nanofibers; (iii) inorganic nanofibers; and (iv) composite nanofibers. All four classes of these can be made in the laboratory by electrospinning of a composition where the crucial component for fiber‐forming is a polymer. Over 50 different types of polymers have been electrospun up to date, and it is safe to assume that conditions allowing electrospinning of almost any polymer can be identified. Incorporating oxides, especially ZnO, TiO2, SnO2, and Al2·O3 in nanofibers has been reported in nanofibers in recent literature.
The promise of nanofibers as a particularly useful material of the future is justified because of several observations. The first has to do with the incredible diversity of nanofiber morphologies fabricated under careful conditions. These include exotic configurations including multichannel fibers where the lacuna is divided into two to five sections, tube in tube nanofibers, core–shell nanofibers, nanowire in nanotube structures, and nanodots