Fabrication of superhydrophobic PDMS/TiO2 composite coatings with corrosion resistance

Abstract

In this study, a combination of hydrothermal and sol–gel methods was used to prepare superhydrophobic polydimethylsiloxane (PDMS)/titanium dioxide (TiO2) composite coatings with good self-cleaning properties and corrosion resistance. The structural, surface roughness and wettability behavior of the PDMS/titanium dioxide superhydrophobic coatings were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, atomic force microscopy and contact angle measurements. The results showed that the surfaces of composite coatings possessed rough hierarchical micro/nanostructures. In particular, the surface water contact angle is as high as 160° and the sliding angle is less than 2.1° when the ratio of PDMS/titanium dioxide was 1:5. Besides, through a series of high-temperature exposure, acid–alkali resistance, self-cleaning and electrochemical corrosion tests, it was found that the superhydrophobic surface with a PDMS/titanium dioxide ratio of 1:5 had excellent properties and showed certain practicability in terms of anticorrosion properties, antipollution properties and durability. Therefore, it can be concluded that this kind of corrosion-resistant superhydrophobic PDMS/titanium dioxide composite coating with simple operation, high performance and multi-scale use on metal substrates has good application prospects in harsh environments.