A facile and straightforward immersion approach to enhance the hydrophobicity of melamine sponge for efficient cleanup of crude oils and organic solvents

Abstract

Abstract The use of biomass-modified hydrophobic materials for cleaning up spilled oils and organic solvents from the environment is currently in high demand. In this study, we developed a simple immersion strategy to modify commercial melamine sponge (MS) using a tetrahydrofuran (THF) extract solution of biomass such as corn stove, pine, and Eucalyptus. This modification process resulted in a highly hydrophobic absorbent with satisfactory superoleophilicity towards various oils (104 g.g-1) and organic solvents (137 g.g-1). The modified MS demonstrated a good oil adsorption capacity with a contact angle of more than 130°. Remarkably, it also exhibited excellent properties of mechanical extrusion, harsh temperature treatment, and recyclability, owing to its three-dimensional high porosity and micro/nano-structure that trap air. Moreover, we found that other biomass extraction solutions such as γ-valerolactone, N, N-dimethylformamide, acetone, methanol, and ethanol could also serve as suitable modification agents to prepare hydrophobic MS through an immersion strategy. The hydrophobicity and stability of the modified MS obtained using this approach were superior to the lignin-modified and DES-extracted lignin-modified MS. Our findings open up new possibilities for the fabrication of modified MS with high hydrophobicity, using a facile, cost-effective, and environmentally-friendly dipping approach for the cleanup of spilled oils and organic solvents.