Preparation and characteristics of graphene oxide-blending PVDF nanohybrid membranes and their applications for hazardous dye adsorption and rejection.

Graphene oxide (GO) and lithium chloride (LiCl) were introduced into poly (vinylidene fluoride) (PVDF) membranes prepared using the immersion precipitation technique. The hydrophilicity, water flux, X-ray diffraction (XRD), zeta potential, SEM and AFM images of membranes were investigated. By adjusting the content of GO from 0wt% to 0.9 wt%, the water flux of PVDF/GO/LiCl nanohybrid membranes varied from 48.4L/mh to 61.90L/mh at 100kPa. Because of the synergistic effects of GO and LiCl particles, the surface free energy (|ΔG|) of M3 (0.5wt% GO) membrane was highest (103.50mJ/m), indicating that the hydrophilicity of M3 membrane was highest. Rhodamine B aqueous solution was firstly used to determine the adsorption and desorption ability of membranes. After 20 cycles, the decolorization rates and flux recovery ratios of nanohybrid membranes exceeded 80% and 78.2% respectively, and the Rhodamine B rejection of M3 membrane was maximum (67.8%) at 100kPa, which illustrated that nanohybrid membranes can be reused as a better ultrafiltration and dye recovery material, and the characteristic of M3 membrane was best.