Electrospun Silk Fibroin Nanofibers with Improved Surface Texture

A new method for preparing silk fibroin (sf) nanofibers with an improved texture and a porous surface is proposed. in order to prepare such nanofibers, sf/poly (ethylene glycol) (peg) blend nanofibers were electrospun and then peg was extracted via selective dissolution technique using methanol. the morphological structure of the electrospun nanofibers were characterized using field-emission scanning electron microscope (fe-sem), infrared spectroscopy (ftir, atr), transmission electron microscopy (tem), differential scanning calorimetry (dsc), and atomic force microscopy (afm). mechanical properties of the nanofiber mats were evaluated with the aid of stress-strain curves. fe-sem and afm images revealed a smooth surface for electrospun sf and sf/peg blend nanofibers with an average fiber diameter in the range of 100-180 nm, while peg extracted nanofibers showed a rough and porous surface with an average diameter in the range of 100-150 nm. the analysis of the atr, dsc, and tem tests revealed that sf/peg blend is an immiscible two phase system in which peg accumulated on the surface of the electrospun blend nanofibers. peg extracted nanofibers showed no internal cavities with a remarkable increase in the surface roughness in comparison to sf and sf/peg blend nanofibers.