Melt Electrospinning Designs for Nanofiber Fabrication for Different Applications

Abstract

Nanofibers have been attracting growing attention owing to their outstanding physicochemical and structural properties as well as diverse and intriguing applications. Electrospinning has been known as a simple, flexible, and multipurpose technique for the fabrication of submicro scale fibers. Throughout the last two decades, numerous investigations have focused on the employment of electrospinning techniques to improve the characteristics of fabricated fibers. This review highlights the state of the art of melt electrospinning and clarifies the major categories based on multitemperature control, gas assist, laser melt, coaxial, and needleless designs. In addition, we represent the effect of melt electrospinning process parameters on the properties of produced fibers. Finally, this review summarizes the challenges and obstacles connected to the melt electrospinning technique.

Keywords: coaxial; gas assist melt electrospinning; laser melt; melt electrospinning; melt electrospinning multitemperature control; nanofibers; setup.

Figure 1

The annual number of English-written journal articles published in the period from 1998–2018, as derived from SciFinder Scholar using the keyword “electrospinning”. As of 6 May 2019, there are 1855 publications.

Figure 2

First experimental melt electrospinning setup (1) chamber, (2) stainless steel wall, (3) aluminum jacket, (4) heater, (5,6) insulator, (7) thermocouple, (8) nozzle, (9) air cylinder, (10) collector, and (11) shaft [28].

Figure 3

Multi-heating zone melt electrospinning [29].

Figure 4

Yarn melt electrospinning: The small dotted circles located around the exit of needles nozzle and the suction wind apparatus are magnified in big dotted circles on the right side, each is pointed out by a red solid arrow to show the role of the suction wind apparatus in combining multiple fibers into one fiber. The hollow red arrows show a vertical and horizontal rotation direction of the collecting roller and rotating disk, respectively [48].

Figure 5

Experimental jet velocity versus spin line for several melt temperatures [26].

Figure 6

Preparation steps for cellulose fibers: (I) Dissolution, cellulose and BmimCl were mixed in the presence of nitrogen for 2 h to form a homogeneous solution; ( II) gels rods preparation, high and low concentration of cellulose were prepared using film casting and crystallization, respectively to be fed by a holder; (III) melt-laser electrospinning setup, fabricating viscous polymer and collecting freeze fiber at −40 °C; (IV) fibers coagulation, fibers were washed in ethanol bath then dried under vacuum [65].

Figure 7

Schematic diagram of melt coaxial electrospinning [71].

Figure 8

Needleless/disc melt electrospinning, where, the melt polymer is drawn out for the reservoir through the edge of the disc once it rotates (retrieved under the terms and conditions of the Creative Commons) [77].