A Facile and Straightforward Immersion Approach to Enhance the Hydrophobicity of Melamine Sponge for Efficient Cleanup of Crude Oils and Organic Solvents

The demand for biomass-modified hydrophobic materials in environmental remediation, particularly for cleaning up spilled oils and organic solvents, has significantly increased. This study introduces a novel approach to enhance the hydrophobic properties of commercial melamine sponge (MS) through a simple immersion strategy employing a tetrahydrofuran (THF) extract solution derived from biomass sources such as corn stove, pine, and Eucalyptus. This modification process yielded a highly hydrophobic absorbent with notable superoleophilicity, capable of absorbing various oils (104 g.g -1 ) and organic solvents (137 g.g -1 ). The resulting modified MS exhibited an expressive oil adsorption capacity, as evidenced by water contact angle exceeding 130°. Notably, its three-dimensional high porosity and micro/nano-structure, conducive to air entrapment, conferred exceptional resilience to mechanical extrusion, harsh temperature treatments, and facilitated recyclability. Additionally, the study explored alternative biomass extraction solutions including γ-valerolactone, N, N-dimethylformamide, acetone, methanol, and ethanol. These solutions were found to be viable modification agents for producing hydrophobic MS through the immersion strategy. Importantly, the hydrophobicity and stability of the modified MS obtained through this method surpassed those of lignin-modified and deep eutectic solvent -extracted lignin-modified MS. This research not only underscores the potential of a facile, cost-effective, and environmentally-friendly dipping approach for enhancing the hydrophobicity of MS, but also opens up new avenues for developing modified MS with superior performance in the cleanup of spilled oils and organic solvents.