Durability, anti-corrosion and self-clean in air/oil of a transparent superhydrophobic polyimide film

Superhydrophobic polymeric materials have received great attention for their flexibility, anti-corrosive and self-cleaning properties. However, superhydrophobicity of ordinary polymers is likely to fail to maintain when they are exposed to a condition of high temperature. Moreover, superhydrophobic materials will lose their self-cleaning property after oil contamination or under oil. Here, we report a transparent superhydrophobic polyimide (PI) film with excellent thermal stability of superhydrophobicity and self-cleaning property after oil contamination using a fluoro- and inorganic-element free approach. Nanoscale poly(divinylbezene) (PDVB) was introduced onto PI film through a one-step solvothermal method. The PDVB@PI film shows comparable transmittance to neat PI film. PDVB@PI film shows excellent self-cleaning property under oil or oil contamination. Moreover, after being heated at 250 degrees C, immersed in liquid nitrogen or UV-irradiation, the film is still superhydrophobic and displays similar water contact angles (WCAs) and rolling angles (RAs) at wide pH region (from 1 to 13) to the untreated PDVB@PI film. PDVB@PI film can keep its optical morphology after the corrosion of 10 M NaOH for 5 h, while the neat PI film is fully damaged. Its superhydrophobicity will not be lost after fire burning process. Therefore, the PDVB@PI film not only satisfies real-life requirements but also has great potential applications in many aspects. (C) 2017 Published by Elsevier Ltd.