MELT ELECTROSPINNING

Two hundred years ago, a deformation of charged liquid under a high-voltage electrostatic fifield was found, and the liquid was polarized by the process of generating jets, which was called electrostatic atomization. After that, numerous scientifific studies were conducted to discuss the instability of the electrostatic liquid under the action of the electrostatic fifield. Since Formhals (Anton, 1934) invented the electrospinning technique in 1934, electrospun fifibers have been attracting a lot of interest due to their high specifific surface area, long length, and easy setups. The high specifific surface area, high porosity (Gopal et al., 2007), and other excellent physical and chemical properties of electrospun nanofifibers show a broad application prospect in biomedical sciences, textiles, environmental protection, biochemical protection, effificient fifiltration, and many other fifields.

There are various methods to obtain nanofifibers, such as melt blowing (Ellison et al., 2007), electrospinning (Hutmacher and Dalton, 2011), the island method (two-component spinning process) (Chen et al., 2001), template polymerization (Klimov et al., 2010), phase separation, self-assembly (Luo et al., 2009), and so on. Some preparation methods for polymer nanofifibers are shown in .

Among these methods, template polymerization, phase separation, and self-assembly can be used to prepare fifibers of tens of nanometers in diameter, but the low effificiency and fifiber discontinuity limit them to the laboratory stage. The main methods for industrial production are melt blowing and electrospinning. The diameter of the fifiber prepared by melt blowing is in the range of micrometers; however, the continuity is poor and the diameter distribution is not easy to control. Electrospinning, by contrast, has many advantages, such as small fifiber diameter, low production cost, and numerous materials to select from.  Electrospinning has been widely considered as the most promising method for the industrialization of nanofifibers in the 21st century in the academic and industrial fifields. Electropinning is a process that can produce continuous fifibers, in the form of a liquid jet, from a polymer solution or melt by electrostatic force using high voltage.

Electrospinning can be done from either a melt or a solution, and each has its own advantages. As an intrinsically safe and green method, melt electrospinning has no solvent evaporation, compared with solution electrospinning (Li et al., 2007; Bellan and Craighead, 2009), and it prepares fifibers without small pores or residual poisonous solvent (Agarwal et al., 2009). However, in addition to the complex devices used to develop polymer melt electrospinning technology, there are three other problems that should be considered as the blow: high-voltage insulation and security issues of the electrospinning system, fifiber refifinement, and productivity. In this chapter focused on melt electrospinning, we provide a historical perspective, and the principles, process research, and fifiber diameters of melt electrospinning are introduced. In addition, some potential applications such as in oil sorption, fifiltration, biomedical sciences, and textiles are described. Also, the confifigurations of melt differential electrospinning are discussed as well as the opinions of the authors as to the future prospects and challenges of melt electrospinning.

Paper link：https://www.sciencedirect.com/book/9780323512701/electrospinning-nanofabrication-and-applications