Superhydrophobic three-dimensional porous ethyl cellulose absorbent with micro/nano-scale hierarchical structures for highly efficient removal of oily contaminants from water

Abstract

The development of efficient absorbent materials is of global importance for oil spillage cleanup and environmental protection. In this work, a novel superhydrophobic micro/nano-scale hierarchical structured ethyl cellulose sponge was successfully fabricated via an eco-friendly salt-templating method followed by immobilizing silver nanoparticles on the surface and subsequent modification with long-chain alkanethiols. The as-prepared sponge with unique micro-nano structure and porous interconnected network exhibited low density (<17 kg m−3), high porosity (>98%) and robust superhydrophobicity (θwater = 161.3°, θoil = 0°, sliding angle = 3.6°). The sponge could collect a wide range of organic solvents and oils with absorption capacity of 36–48 times of its own weight. Furthermore, the absorption capacity decreased slightly to 89.8% of its initial value after 50 cycles, demonstrating excellent recyclability of the sponge. It was believed that the superhydrophobic/superoleophilic sponge would be a promising absorbent material for the selective oil removal and recovery in environmental remediation.