Investigating the influence of temperature on electrospinning of polycaprolactone solutions

The present work shows the effect of temperature on successfully obtained uniform electrospun poly (epsilon-caprolactone) (PCL) fibers, with specific attention to the molecular orientation and diameter of nanofibers. Experiments were performed at temperatures (T) of 25, 35, and 45 degrees C, and at PCL concentrations (w) of 12, 16, and 20 wt.%. Scanning electron microscopy provided the morphology of electrospun fibers and quantified their diameters. Elevated temperature for all PCL concentrations yielded a viscosity that allows for easier stretching of the jet to obtain a smaller diameter for fibers. A minimum size of the fiber diameter (close to 100 nm) was achieved for the set point T = 45 degrees C and w = 12 and 16 wt.%. Due to the easy stretching of the jet by controlling the elastic property of the solution, a dichroic ratio of 1.62 was accessible for the set point T = 35 degrees C and w = 12 wt.% from polarized Fourier transform infrared spectra as a factor for the orientation of PCL chains.