Effects of Solvent Properties, Solvent System, Electrostatic Field Strength, and Inorganic Salt Addition on Electrospun Polystyrene Fibres.

This work reports the effects of solvent properties, solvent system, electrostatic field strength, and inorganic salt addition on electro-spinnability of the as-prepared polystyrene (PS) solutions and morphological appearance and/or size of the resulting fibres. The single solvents were 1,2-dichloroethane (DCE), dimethylformamide (DMF), ethylacetate (EA), and methylethylketone (MEK), while the mixed solvents were DMF/DCE, DMF/EA, and DMF/MEK at a fixed volumetric ratio of 75/25. The PS solution 10% (w/v) in DMF was found to exhibit the highest electro-spinnability, followed by its solutions in DCE, MEK, and EA, respectively. Generally, electrospinning of 10% (w/v) PS solution resulted in the formation of the beaded fibres, while electrospinning of 20 and 30% (w/v) PS solutions only resulted in the formation of smooth fibres. The size of the obtained fibres was found to increase with an increase in both the electrostatic field strength and the concentration of the PS solutions. Interestingly, the presence of DCE, EA, and MEK as the minor solvent (at 25 vol%) in a mixture with DMF reduced the size of the obtained fibres. Finally, incorporation of LiCI and KCI to modify the conductivity of the PS solutions caused the size of the fibres to increase appreciably.