Highly efficient reusable superhydrophobic sponge prepared by a facile, simple and cost effective biomimetic bonding method for oil absorption.

Superhydrophobic sponges have considerable potential for oil/water separation. Most of the methods used for superhydrophobic modification of sponges require toxic or harmful solvents, which have the drawbacks of hazardous to environment, expensive, and complex to utilize. Moreover, the hydrophobic layer on the surface of sponge is often easily destroyed. In this paper, a highly efficient superhydrophobic sponge with excellent reusability was developed by using a facile, simple and environmentally friendly dopamine biomimetic bonding method. Different types of sponges, such as melamine, polyethylene or polyurethane sponge wastes, were used as raw materials to prepare superhydrophobic sponges, which possess the advantages of inexpensive and abundant. The effects of different dopamine polymerization time and different hydrophobic agent dosage on the hydrophobicity and oil absorption capacity of melamine sponges were optimized. The study results showed that the water contact angle of the superhydrophobic sponge could reach 153° with excellent organic solvent absorption capacity of 165.9 g/g. Furthermore, the superhydrophobic sponge retained approximately 92.1% of its initial absorption capacity after 35 reutilization cycles. More importantly, the dopamine biomimetic bonding superhydrophobic modification method can be used for different types of sponges. Therefore, a universally applicable, facile, simple and environmentally friendly superhydrophobic modification method for sponges was developed.