Excellent self-cleaning surface achieved through the synergistic effect of superhydrophilicity and photocatalysis of PVDF-TiO2-HAP coating

With the increasing demand for living environment, high-performance self-cleaning coatings have become an urgent need in the development of new building industry. Herein, a TiO2-HAP-PVDF self-cleaning coating was successfully developed using a facile precursor mixing method, where porous hydroxyapatite (HAP) was used to facilitate the adsorption of pollutants, TiO2 served as photocatalyst to decompose pollutants, and polyvinylidene fluoride (PVDF) served as adhesive to combine TiO2 with HAP. Owing to the synergistic effect of superhydrophilicity and photocatalysis, the TiO2-HAP-PVDF coating displays outstanding self-cleaning performance. Furthermore, the as-fabricated coating attached to aluminum veneer not only resists mechanical abrasion such as rainwater, sand flow and sandpaper, but also exhibits good stability in the extremely temperatures from -196 to 150 °C, as well as in strong acid and alkaline solutions, and even presents satisfactory performance after 8000 hours of outdoor service test. These merits open exciting possibilities for the industrial application of self-cleaning coating.