Study on intelligent bionic superhydrophobic material and its oil-water separation mechanism.

In this study, an environmentally friendly, simple process and high-performance Fe3O4@SiO2@PMMA-based smart bionic superhydrophobic oil-absorbing material was developed for effectively collecting and removing oil pollutants from water. By studying the effects of Fe3O4 particle size, PDMS concentration, and heating time on the superhydrophobicity of the materials, the directional regulation of superhydrophobicity and oil-water separation performance of Fe3O4@SiO2@PMMA@PDMS materials was realized. The results showed that the material exhibited optimal performance when the Fe3O4 particle size combination was 20/500 nm/1 μm, the mass ratio of PDMS to Fe3O4@SiO2@PMMA was 7:1, and it was heated at 350℃ for 1 minute. The coating achieved a contact angle of 158.7° and a rolling angle as low as 4.9°. This coating not only remained superhydrophobic after a 21 m abrasion test and 288 h immersion in acid, alkali, salt, and high-temperature solutions, but also efficiently separated oil-water mixtures, with separation efficiencies of over 99.78% were achieved for trichloromethane, dichloromethane and bromoethane. Furthermore, superhydrophobic magnetic polyurethane sponge (SFPU) prepared using Fe3O4@SiO2@PMMA not only exhibited excellent oil-absorbing capacity (11-28 g/g), but also realized precise oil absorption at multiple sites by magnetic conduction. In the actual oily wastewater test, the oil-water separation efficiency of the sponge reached 90.58% .