Research on multilayer graphene synthesis for oil and solvent adsorption in water

Abstract

In this study, multilayer graphene (GNPs) was successfully prepared through direct chemical exfoliation from natural graphite flakes. The characteristics of the GNPs were investigated using scanning electron microscopy and XRD. The results showed that the GNPs had a low bulk density of only 0.012 g mL-1, a C content of 99%, lateral diameters ranging from 6-16 µm, and a thickness of less than 15 nm. The absorption capacity of the GNPs for a range of oils and organic solvents including pump oil, polydimethylsiloxane (PDMS) oil, dioctyl phthalates (DOP) oil, olive oil, bean oil, mazut oil, xylene, ethanol, and ethylene glycol (EG) was evaluated. The effects of the absorption conditions such as absorption time (sorption kinetics), temperature, and aging method (static, stirring, and ultrasonic) on the absorption capability of the GNPs were also investigated. It was observed that the GNPs exhibited extremely high absorption capacities for oils and organic solvents, up to 20-40 times their own weight after just 2 minutes of absorption at room temperature, which was significantly higher than many commercially available absorbent materials.