Novel application of graphene oxide to improve hydrophilicity and mechanical strength of aramid nanofiber hybrid membrane

The synergy effect of nano-materials with composite membrane has provided numerous opportunities to strengthen the performance of the membrane in all-around research territories. Previous studies have demonstrated that bulk aramid macroscale fibers can be effectively split into aramid nanofibers (ANFs) by dissolution in dimethylsulfoxide (DMSO) in the presence of potassium hydroxide (KOH). Addressed herein is a facile and low-cost approach to endow hydrophobic Kevlar nanofiber membranes with reliable hydrophilicity and improved mechanical strength. Introduction of Graphene oxide (GO) into the structure of ANFs membranes was realized through π-π stacking interactions and aramid nanofiber-graphene oxide (ANFGs) hybrid membranes contained gradient concentrations of GO with enhanced hydrophilicity and mechanical strength were synthesized. The structure, composition and mechanical properties of hybrid membranes were characterized by FT-IR, XRD, SEM and Universal pull machine. Within the range of GO loadings assessed in this work, it was found that the ANFGs with GO 0.75 wt.% and 1.0 wt.% provide optimal potentiation both on tensile strength (377 ± 3 MPa) and Young's modulus (18.36 ± 0.87 GPa). The hydrophilicity of the ANFGs membranes was assessed by water contact angle measurements which showed that medium GO content (1 wt.%) result in the most hydrophilic coating with the lowest contact angle of 53 ± 0.4°. ANFGs hybrid membranes offered not only remarkable mechanical performance, but also better hydrophilicity which should be due to abundant functional groups in GO, indicating great potential of such membranes in water industry.