Superhydrophobic silk fibroin-silica melamine sponge for efficient oil–water separation

This study developed a facile and environmentally-friendly method to prepare SiO 2 /silk fibroin (SF) composite melamine sponges modified using SF and hydrophobic SiO 2 nanoparticles (NPs). During the preparation procedure, the SiO 2 NPs were bonded to skeletons of porous sponges with the SF binding agent using a dip-coating method. The SiO 2 NPs and SF with hydrophobicity constructed a rough surface. The obtained sponges possess a high absorption capacity of 70.9–160.8 times of its weight for various oils and organic solvents and a high water-contact angle greater than 151°. More importantly, the modified sponges showed good recyclability, and could return to its original shape even after 100 cyclic compression. The as-prepared sponge also showed high buoyancy outstanding elasticity, and maintained high absorption capacity even after 10 cycles of repetitive absorption-desorption. The prepared sponges could efficiently separate oil or organic solvents from oil–water mixtures, indicating that the SiO 2 /SF/MS sponges are promising candidates for remediating oil spills and oily wastewater.