▎ 摘　　要

The morphological appearance, fiber diameter, and structure of poly(epsilon-caprolactone) (PCL) nanofibers produced by the electrospinning process were studied in the presence of different amounts of graphene oxide (GO) with different oxidation levels. Scanning electron microscope micrographs of electrospun fibers showed that the average fiber diameter decreases in the presence of GO with different loading and oxidation levels. The loading level of GO especially higher than 0.3 wt% was influential in decreasing the diameter of PCL electrospun fibers rather than oxidation level. Contact angle, infrared spectroscopy, and conductivity measurements on graphite oxide (GtO) samples, as well as rheological, conductivity, and surface tension experiments on PCLGO solutions were performed to describe the role of GO in the significant reduction of fiber diameter. It was found that three factors are involved in generating a driving force for more stretching of the electrospinning jet. One is the viscosity reduction of PCLGO solution, which intensifies by more GO content and less GO oxidation level. The second is solution conductivity which enhances by GO loading and the third is the charge relaxation time of the spinning solution, which grows with increasing the oxidation level of GO as well as the GO content. (C) 2014 Society of Plastics Engineers