A superhydrophobic and elastic melamine sponge for oil/water separation

Abstract

The leakage of industrial oil and organic solvents can wreak great harm to the environment and ecology. Therefore, development of a low-cost and high-performance adsorption material to solve this problem is crucial. The modification of sponge materials has become a “hot topic” in oil/water separation. We employed mild heat treatment to fabricate a superhydrophobic melamine sponge (SMS) with a water contact angle of ≤168 ± 5°. The hydrophobicity of the SMS originated from the decreased surface energy, which was due to the elimination of hydroxyl groups, and adsorbed water and ammonia in the pristine melamine sponge (MS). The prepared SMS possessed superhydrophobicity, excellent elasticity, high porosity, low density and excellent efficient oil/water separation performance. The obtained SMS also had great compressive durability and cyclic properties. Moreover, the SMS could maintain excellent adsorption performance for various oils and organic solvents over 50 cycles by squeezing and exhibited extremely high separation efficiency of ≤4.5 × 10⁶ L m⁻³ h⁻¹ in turbulent and non-turbulent oil/water systems. Thus, this SMS could be a candidate for large-scale recovery of oil or organic solvents from water resources.