Superhydrophilic nano-TiO2 film with porous surface structure

The TiO2 films prepared from a sol-gel precursor were deposited on glass substrates using spin coating technique. Titania sols were doped with and without a pore generating agent, polyethylene glycol (PEG), to evaluate the effect of porosity on the superhydrophilicity of the coatings. The crystalline phase and surface morphology of the TiO2 thin films were characterised by XRD, SEM and scanning measurement station (SMS). Wetting behaviour of the resulting films were characterised using contact angle measurements. This particular porous surface prepared from 0.5M tetrabutyl titanate with PEG sintered at 450 degrees C was in anatase form and has maximum specific surface area and average roughness. The results show that the PEG doped anatase TiO2 film exhibits superhydrophilic characteristic, although it is not exposed to ultraviolet irradiation. Finally, the formation mechanism and the property-structure relationship were discussed in detail.