Fabrication of recyclable, superhydrophobic-superoleophilic quartz sand by facile two-step modification for oil-water separation

With the highly frequency of oil spillages and chemical leakages, the application of superhydrophobic surface in oil-water separation is promising. Herein, the myristic acid/TiO2@raw quartz sand (MATC@sand) with superhydrophobic-superoleophilic properties has been judiciously designed and synthesized that could be utilized for oil-water separation. The as-prepared samples were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectrometer (XPS) and Fourier transform infrared spectroscopy (FTIR). The wetting behavior was evaluated by contact angle measurer and the result showed that the MATC@sand had a water contact angle of 165.0 degrees, a sliding angle less than 5 degrees and an oil contact angle of 0 degrees, which endowed the modified quartz sand with efficiently implement oil-water separation in various modes. The mechanism of oil-water separation using MATC@sand was exploited and it demonstrated the excellent ability of oil-water separation was mainly attributed to the synergistic effect between rough hierarchical micro/nanostructures and low surface energy. Moreover, for the sake of demonstrating its performance in practice application of oil-water separation, the durability, self-cleaning capacity, thermostability and anticorrosion of the MATC@sand are also measured to ensure the practical application. The results proved that the functional quartz sand is recyclable, economical and readily available, which made it have great prospects in practical application.