Fabrication of SiO2/TiO2 coated polyethylene films with photoinduced superhydrophilicity, antifogging property and mechanical robustness

Abstract

Anatase type TiO2 has garnered significant attention due to its potent oxidation capacity, stability, photoinduced superhydrophilicity and self-cleaning performance. However, there are few reports on the preparation of robust TiO2 films on substrates with a low glass transition temperature. In this work, SiO2/TiO2 films were fabricated on PE substrates using a simple dip-coating technique. The coated PE films exhibited a maximum transmittance of 86 % and an average transmittance of 85 % in the visible region. The composite films demonstrated remarkable photoinduced superhydrophilicity, antifogging characteristics, and excellent photocatalytic performance. The film showed superhydrophilicity under UV light or xenon lamp illumination, and remained superhydrophilicity after it was placed outdoors for 310 days. In addition, the prepared films also had excellent mechanical properties, and their superhydrophilicity remained unaffected even after 200 cycles of bending, 80 cycles of rolling, and 50 mL water impact test. The preparation method may open a new avenue to the application of TiO2 films on many substrates that are vulnerable to high temperature processes.