Effects of Emulsion Electrospinning Parameters on the Morphology and Structure of Core-Shell Structured PLLA Fibers

Electrospinning is a popular technique for producing micro-or nanofibers for diverse applications including filtration, catalysis, sensors, cosmetics, wound dressing and tissue engineering. In some applications such as controlled drug/biomolecule delivery, core-shell structured nanofibers are desired. There are two major electrospinning processes for making core-shell structured fibers: emulsion electrospinning and coaxial electrospinning. In this study, the formation of core-shell structured fibers of poly (L-lactic acid) (PLLA) through emulsion electrospinning was investigated. To study the electrospinability of emulsions based on PLLA solutions, two solvents, pure chloroform and mixed solvent of chloroform and N,N-dimethylformamide, were used separately for making PLLA solutions. In the study of the formation of controlled release systems for biomolecules, bovine serum albumin, a model protein, was dissolved in de-ionized water to make the water phase in emulsions. In emulsion electrospinning, parameters such as applied voltage, working distance and feeding rate, were systematically investigated. The morphology, diameter and core-shell structure of emulsion electrospun fibers was studied using electron microscopies.