Bio-inspired, multi-purpose and instant superhydrophobic–superoleophilic lotus leaf powder hybrid micro–nanocomposites for selective oil spill capture

Abstract

Materials with superhydrophobic and superoleophilic properties are exhibited naturally in lotus leaves. Inspired by lotus leaves, lotus leaf (LL) powder was used in this study to prepare a new type of bio-inspired, multi-purpose, environmental friendly and inexpensive instant superhydrophobic–superoleophilic hybrid. The cast hybrid surface exhibited almost complete superhydrophobicity (water contact angle (CA) > 175°) on a variety of substrates and superoleophilicity (oil CA < 5°) for various oils. The surface also exhibited excellent thermal stability and mesoporous structure, and became superhydrophilic on curing at 600 °C. A dip coated hybrid–poly(dimethylsiloxane) (PDMS) sponge exhibited very high selectivity and absorption capacity for a range of oils and organic solvents (2000 to 3600 w/w% to absorbent) in deionized water.