Hydrophobically modified bulk coke as a novel carbonaceous sorbent for removal of organic solvents

Abstract

Designing a concise hydrophobic modification strategy for carbonaceous materials still faces challenge. In this work, the bottom-up method of growing polysiloxane nanofilaments is used for hydrophobic modification of bulk coke. Polysiloxane nanofilaments formed on the bulk coke surface not only reduce the surface energy, but also increase the surface roughness, thus achieving the synchronization of roughening and energy reduction. The water contact angle of modified coke can be up to 144°, showing an outstanding water repellency. Depending on the imparted hydrophobicity, the modified coke can be used as a novel carbonaceous sorbent to selectively remove hydrophobic organic solvents from water. A diverse of different organic solvents can be absorbed by the modified coke. After 20 consecutive cycles, the value of absorption capacity of the modified coke still remains stable, holding an exceptional recyclability. The utilization method of coke and the hydrophobic modification strategy proposed in this work provide a new idea for the functionalization of other carbonaceous materials.