Enhanced separation flux and compressive strength for oil-water separation by adding sodium lignosulphonate

Abstract

Oil-water separation materials have been deeply developed to solve oil spill problems. However, mechanical strength and separation efficiency remain challenging. Based on the electrostatic repulsion, we design and prepare oil-water separation materials to enhance the separation flux and resistance to pressure by adding sodium lignosulphonate nanoparticles (LSs) to the reduced graphene oxide (rGO), followed by surface modification with trimethoxymethylsilane (MTMS). XRD patterns prove the positive action of LSs for improving interlayer spacing of rGO, which contributes to an excellent separation flux (carbon tetrachloride/water, 43209.71 L⋅m-2⋅h-1) of MLNGA. The compressible recovery ability is enhanced to 49.91 kPa under 80 % strain. The MLNGA presents excellent separation efficiency (∼99.12 %) on a continuous oil-water separation device. All these results indicate the outstanding performances and potential of MLNGA in oil–water separation applications. Moreover, this design concept involves electrostatic repulsion and may be promoted to other anionic macromolecules such as sodium alginate, tannic acid, and pectin.