Fabrication of Core-Sheath Nanocomposite Fibers by Co-axial Electrospinning

This study investigates the fabrication of core-sheath nanocomposite fibers by locating germanium (Ge) and silicon dioxide (SiO2) nanoparticles selectively in the sheath layer by co-axial electrospinning. Co-axially spun fibers were prepared by electrospinning a pure PVA solution and Ge/SiO2/PVA solution as the core and sheath layer, respectively. Core-sheath nanocomposite fibers were electrospun under a variety of conditions that include various feed rates for the core and sheath solutions, voltages, and concentric needle diameters, in order to find an optimum spinning condition. Ge/SiO2 nanocomposite fibers were also prepared by uni- axial electrospinning to compare fiber morphology and nanoparticle distribution with core-sheath nanofibers. Using scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analy- sis, it was demonstrated that the co-axial approach resulted in the presence of nanoparticles near the surface region of the fibers compared to the overall distribution obtained for uni-axial fibers. The co-axially elec- trospun Ge/SiO2/PVA nanofiber webs have possible uses in high efficiency functional textiles in which the nanoparticles located in the sheath region provide enhanced functionality.