Raman microscopic imaging of electrospun fibers made from a polycaprolactone and polyethylene oxide blend

Raman spectroscopy is a useful technique for providing compositional information about samples. By combining this technique with microscopy, Raman data can be collected from domain sizes smaller than one micron in diameter. This research aims to utilize this technique to examine the submicron component distribution in electrospun nanofibers. Nanofibers containing a 50:50 blend of polyethylene oxide (PEO) and polycaprolactone (PCL) were analyzed using Raman microscopy and scanning electron microscopy (SEM). This was performed before and after the samples were incubated in Milli-Q water to observe the effects of PEO dissolution on the nanofiber structure. Raman results indicate that both polymers are distributed evenly throughout individual nanofibers, but that some nanofibers may contain more of one component than the other, and the technique provided direct evidence for PEO dissolution after submersion in water. The dissolution of PEO observed by Raman microscopy correlated with results of mass loss analysis. SEM results also provided evidence for component dissolution and suggest that electrospinning may result in the formation nanofibers made up of PEO and PCL nanofibrils.