Graphene oxide-assisted preparation of poly(vinyl alcohol)/carbon nanotube/reduced graphene oxide nanofibers with high carbon content by electrospinning technology

Abstract

In this article, poly(vinyl alcohol) (PVA) based nanofibers with high carbon content were prepared via electrospinning technology. Graphene oxide (GO) was used as the dispersing agent to improve the dispersion of the multi-walled carbon nanotubes (MWCNTs) in the electrospinning solution and the PVA based nanofibers, and as the precursor of graphene. The microstructure of the PVA/GO/MWCNT nanofibers was examined via field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The FESEM/TEM results show that the MWCNTs were dispersed well in the PVA matrix with the assistance of GO. The stability of the PVA/GO/MWCNT nanofiber mat in aqueous solution is enhanced via the crosslinked network formed after crosslinking with glutaraldehyde (GA). Then, a PVA/RGO/MWCNT nanofiber mat was obtained by the reduction of GO after the crosslinked PVA/GO/MWCNT nanofiber mat was soaked in hydrazine hydrate solution. The I_D/I_G value of the GO in the nanofibers increased from 0.83 to 1.11 after reduction with hydrazine hydrate at 95 °C for 1 hour, which indicated that the reduction of GO did take place. After the addition of GO, the tensile strength of the PVA nanofiber mat decreased from 16.7 ± 0.7 MPa to 13.2 ± 0.8 MPa. After the addition of MWCNTs, the tensile strength of the PVA/GO nanofiber mat increased from 13.2 ± 0.8 MPa to 18.1 ± 0.5 MPa. At the same time, the crosslinked network also enhanced the tensile strength of these nanofiber mats. The volume conductivity of the PVA nanofiber mat increased from 5.11 ± 0.96 × 10⁻¹¹ S m⁻¹ to 2.33 ± 0.20 × 10⁻⁷ S m⁻¹ when the carbon content in the PVA based nanofibers reached 21 wt%.