Facile preparation of TiO2/SiO2/modified polystyrene resin composite superhydrophobic coatings for self-cleaning and oil/water separation

Various methods have been exploited to treat oil/water mixtures, but they are not suitable for widespread application due to high cost or low efficiency. Superhydrophobic materials with water-repellent and lipophilic are desirable materials for the separation. Here, composite superhydrophobic coatings, capable of applying to a variety of substrates, were developed using a simple co-blending method of dispersing fumed TiO2 nanoparticles (NPs) and hydrophobic silica sol into non-fluorinated modified polystyrene resin (MPS). The properties of the coating were investigated by a variety of techniques such as FTIR, FESEM, TG-DSC, and contact angle measurement. The results suggested that the surface had exceptional superhydrophobicity with the WCA as high as 160.8 degrees. The coating remained superhydrophobic after 3 times of sandpaper abrasion. The superhydrophobic surface had excellent self-cleaning properties and could be applied to separate the oil/water mixture. The separation efficiency could be over 96% and remained stable after 5 cycles. It is a great prospect in the treatment of oily wastewater. Furthermore, the reagents and instruments used during the procedure are easily available, so it has the potential for production in large quantities.

Automated summary

In this study, a composite superhydrophobic coating capable of applying to a variety of substrates was developed, which exhibited exceptional superhydrophobicity and self-cleaning properties for the efficient separation of oil/water mixtures. The reagents and instruments used in the procedure are easily available, suggesting the potential for large-scale production.