Trisiloxane functionalized melamine sponges for oil water separation

The trisiloxane modified melamine sponges (3Si-MS) have been successfully fabricated via the formation of polydopamine (PDA) layer with nanoaggregates and the covalent grafting of 3-mercaptopropyltrisiloxane. The 3Si-MS were confirmed and verified by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR), contact angle, the separation/adsorption tests and recyclability tests. As investigated by SEM, 3Si-MS exhibited 3D hierarchical structure with high density of nanoaggregates on the interconnected skeleton of melamine sponges. By combining the shorter and wider hydrophobic group of trisiloxane and hierarchically rough structure, 3Si-MS illustrated highly hydrophobic (water contact angle of 139.3 degrees), outstanding absorption capacity, and easy reusability. Meanwhile, 3Si-MS could be used for continuous oil-water separation. The results of this work demonstrate a facile and cost-effective method to prepare highly hydrophobic melamine sponges for oil-water separation.