Recyclable and biodegradable superhydrophobic and superoleophilic chitosan sponge for the effective removal of oily pollutants from water

Superhydrophobic and superoleophilic chitosan sponge (MCTCS) was successfully prepared via a facile freeze-drying method with the assistance of TPP/citral crosslinking and octadecanethiol modification. The three dimensional porous structure endowed the MCTCS sponges with large pore volume and good compressive property. Moreover, the MCTCS sponge could effectively absorb oil with an absorptive capacity up to 60 times of its own weight. More importantly, the MCTCS sponge could selectively absorb the emulsified oils in water effectively, and achieve continuous oil–water separation with the assistance of peristaltic pump. The oil and water separation efficiency was up to 99%. Furthermore, the MCTCS sponge still maintained a highly absorptive capacity after being reused for many cycles and possessed ideal biodegradability. It was believed that the superhydrophobic/superoleophilic chitosan sponge would be a promising absorbent material for the removal of oil from water in environmental remediation.