Highly mesoporous and compressible sugarcane aerogel via top-down nanotechnology as effective and reusable oil absorbents

Absorption is one of the most important methods for oil spill cleanup. An ideal absorbent is expected to possess advantages of low cost, green, high absorption capacity and excellent reusability. In this paper, a facile and environmentally-friendly top-down approach was developed for the preparation of the highly mesoporous and compressible sugarcane aerogel. Individualization of cellulose microfibrils within the sugarcane cell wall structure without introducing mechanical disintegration was realized, prepared by oxidation of delignified sugarcane at the neutral condition with TEMPO/NaClO/NaClO 2 system. The results proved that the cellulose nanofibers in the cell wall maintains their natural alignment structure. The high fibril orientation and ordered arrangement of the network-like microstructure can be processed into anisotropic aerogels with high porosity (98.8%) and high compressive strength (0.53 MPa at 80% strain). The increased porosity and partial cellulose fibrillation result in specific surface areas of 32.94 m 2 /g. Subsequent hydrophobic coating with methyltrimethoxysilane, the hydrophobic and oleophilic sugarcane aerogel (water contact angle as high as 145.73°) was capable of adsorbing a wide range of organic solvents and oils (22.8 ~ 40.2 g/g). Moreover, the porous aerogel maintained a high oil-absorption capacity after absorbing and squeezing multiple times. This new sugarcane aerogel offers potential possibilities for the subsequent in high efficiency oil–water separation applications.