Ambient-dried, natural palm tree trunk–based hydrophobic foam for efficient oil sorption

Bio-based sorbents like foams prepared from surface-modified cellulose fibers (CF) have the potential to be a sustainable option for cleaning up oil spills and treating industrial wastewater. This is due to their lightweight nature, high porosity, and effective sorption capabilities. However, their current utilization is limited by expensive preparation procedures, prolonged processing, and the use of unsafe chemicals. In this research, a low-cost and simply scalable super-natural cellulose fiber foam was developed using palm tree trunk as the cellulose source and menthol as the agent for making pores. Menthol occupies spaces between the cellulose fibers, helping to maintain the structure and minimize shrinkage of the samples. By sublimating menthol crystals at the end of the process, the final foam was obtained. Instead of traditional silane treatments, biodegradable beeswax was used to enhance the hydrophobic properties of the foam's surface. The treated foam exhibited a water-contact angle (WCA) of 137.47°, an oil sorption capacity ranging from 13.6 g/g to 10.8 g/g for oils and organic solvents, and remarkable recyclability even after 10 cycles. These findings propose that this foam has the potential for applications in oil recovery and environmental protection. • A super natural-based aerogel was prepared by ambient pressure drying. • Menthol was used as pore-making agent of the final lightweight cellulose aerogel. • Bio-degradable nontoxic beeswax was used to improve the hydrophobicity.