Thermal and mechanical performance of electrospun chitosan/poly(vinyl alcohol) nanofibers with graphene oxide

In this paper, electrospun chitosan (CS)/poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanofibers were fabricated. Prepared nanofibers have been characterized and investigated for their morphological, structural, and thermal stability, and mechanical and hydrophilic properties. The uniform and defect-free nanofibers were obtained and GO, shaping spindle and spherical, was partially embedded into nanofibers, as shown in SEM. The hydrogen bonds between CS molecules and PVA molecules were easily formed due to the great compatibility of CS and PVA. The addition of GO interrupted the hydrogen bonds between CS molecules and PVA molecules, and the new interaction was formed among CS, PVA, and GO. Thermogravimetric analysis indicated that as the increasing of content of GO, the thermal stability of nanofibers decreased. More interestingly, the static mechanical properties tests and dynamic mechanical analysis all showed that the modulus of nanofibrous mats increased firstly and decreased subsequently with the increasing of content of GO, which could be concerned with the looser arrangement of nanofibers. The water contact angle of nanofibrous mats increased with the increasing of content of GO. Nevertheless, when the content of GO was up to 2.5 wt%, the water contact angle decreased significantly.