Design of superhydrophilic surfaces on metallic substrates by the fabrication of Ti-containing mesoporous silica thin film

Ti-containing mesoporous silica thin films (Ti-MSTFs) have been prepared on Al and Al–Mg alloy substrates via a sol–gel/spin-coating method including two different processes for removal of a structure directing agent (SDA). One is calcination and the other is photocatalytic removal under UV-light irradiation utilizing photocatalysis of tetrahedrally coordinated titanium oxide moieties within the silica framework. Characterizations of mesoporous structures and local structures of titanium oxide moieties were performed by FT-IR, XRD, and UV–vis measurements. Water contact angle measurements revealed that highly hydrophilic surfaces were successfully formed on both metallic substrates by coating with Ti-MSTFs. These surfaces also exhibited photoinduced superhydrophilic properties under UV-light irradiation.

Figure optionsDownload high-quality image (74 K)Download as PowerPoint slideResearch highlights▶ Ti-containing mesoporous silica thin films were prepared on Al and Al–Mg substrates. ▶ Ti-oxide moieties existed in tetrahedrally coordinated states. ▶ Ti-oxide moieties acted as photocatalysts for decomposition of a template. ▶ Wettabilities of metallic substrates were converted into highly hydrophilic. ▶ Metal surfaces coated with the film exhibited photoinduced superhydrophilicity.