Electrospinning of poly(ethylene-co-vinyl acetate)/clay nanocomposite fibers

Poly(ethylene-co-vinyl acetate)/clay nanocomposite fibers were fabricated using electrospinning. The fiber diameters were controlled by varying the polymer/ chloroform concentration, which resulted in fibers with diameters ranging from 1 to 15 μlm. The clay concentration was varied from 0.35 to 6.6 wt %. Scanning electron microscopy revealed that the fiber diameter increased with increasing clay concentration, whereas beading decreased. Transmission electron microscopy revealed a disruption of the spherulite structures by clay, which is consistent with heterogeneous nucleation. Shear modulus force microscopy indicated a reduction in melting point (T_m) with decreasing diameter for fibers thinner than 15 μm, which was confirmed by temperature dependent X-ray diffraction data. For fibers thinner than 8 μm, the presence of clay further enhanced the reduction of T_m.