Supercritical fluid-assisted electrospinning

Supercritical fluids have been recognized as typical green solvents and possess physical properties that are intermediate to those of gas and liquid states. These properties are continuously tunable with the change of pressures and/or temperatures; therefore, supercritical fluids can be used as a solvent in many distinct areas of applications. Supercritical fluids have also been applied to replace many environmentally hazardous organic solvents currently deployed in industry. Carbon dioxide (CO₂) is the most beneficial supercritical fluid employed in many applications. Supercritical CO₂ has ability to swell and to plasticize polymers; hence the impregnation, the foaming, and the modification of polymeric materials can be performed when supercritical CO₂ is used as a medium in polymer processes. Here, CO₂ at near- and supercritical conditions was used as a medium to generate polymer fibers from a solution of polymer through electrospinning process. This chapter shows that this process is new and offers the possibility that electrospinning process at near- and supercritical CO₂ will be a necessary and beneficial technique for fibers production with hollow interiors.