Preparation of SiO2-polydimethylsiloxane-octadecyltrichlorosilane superhydrophobic coating and its self-healing performance

The self-healing performance of superhydrophobic coatings is an important property to enhance the durability and self-cleaning character, which has been a focus of surface modification in recent years. In this work, a simple method was proposed for preparing the superhydrophobic coatings with self-healing properties on slides using nano-SiO2, octadecyltrichlorosilane, and polydimethylsiloxane. The hydrophobic properties, morphologies, compositions, structures, stability, and self-healing properties were respectively investigated via various characterizations and tests. The results indicated that the self-healing properties of the coatings were induced by the Si-O-Si bonds through X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The best self-healing property and hydrophobicity after healing were obtained when the content of polydimethylsiloxane was 35% (wt.), and the contact angle of water would arrive at 160.98° when the concentration of nano-SiO2 was 3% (wt.). The contact angle of each coating surface remained stable and thermally stable when the temperature was increased from 100 to 300 °C ( Tg), and the coatings remained stable under natural acidic and alkaline environments as well as mechanical shocks. So superhydrophobic coatings with self-healing performance have potential applications for the development of durable surfaces.