Optimization of the experimental parameters for the design PCL-ZnO electrospun fibers with tunable hydrophobicity

In this work, a comparative study is presented that uses the electrospinning technique for the design and development of functional surfaces with a desired morphology in terms of wettability and corrosion resistance. With the aim to obtain the coatings with the best properties, a strict control of several input operational parameters (mostly applied voltage, flow rate, and collector distance) has been performed. In addition, a dual effect associated to the polymeric precursor concentration (polycaprolactone, PCL) and ZnO nanoparticles proportion has been also evaluated for showing a key role in the final properties. It has been demonstrated that the solution concentration has a significant effect on the structure in the final polymer obtained on the collector, being possible the formation of beads with a spherical shape or spindle-like beads at low solution viscosities. Moreover, the presence of the ZnO nanoparticles plays an important role in the wettability behavior of the electrospun fibers. Finally, in order to evaluate the coating morphology for the better performance, the following parameters, such as fiber diameter, surface roughness (Ra), corrosion rate, and wettability have been deeply analyzed.