Super-hydrophobic chitosan/graphene-based aerogels for oil absorption

Oil spills pose a significant hazard to both the environment and humans, so they must be addressed. The current study recommends the usage of aerogels derived from biopolymers. For their synthesis chitosan (CS), polyvinyl alcohol (PVA), graphene oxide (GO), and reduced graphene oxide (rGO) were used, with glutaraldehyde (GLA) being the cross-linking agent. Aerogels were obtained through the freeze-drying method and they went through hydrophobic modification. The composites were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET), scanning electronic microscopy (SEM), and their mechanical properties were tested. CS/PVA/GO and CS/PVA/rGO aerogels show amphiphilicity and high absorption capacity for both water (16–22 g/g) and diesel oil (17–27 g/g), while the silane-modified exhibited extreme hydrophobicity. Kinetics analysis showed that the sorption mechanism consists of 2 stages and the data fit better the pseudo-second order kinetic model, while SEM and BET analysis, confirmed the porous structure and high surface area of aerogels. CS/PVA/GO and CS/PVA/rGO can be used effectively in an oil-spill accident for oil/water separation process.