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

Abstract

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°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 10M NaOH for 5h, 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.