Fig xA XRD patterns of TiO porous films
Surface morphologies of TiO2 films were investigated by an LEO 1530 VP field emission scanning electrons microscope (SEM). Fourier transform-infrared spectra (FTIR) of TiO2 sols spread on KBr pellets were recorded on a Bruker Vector 33 spectrometer with 6 cm−1 resolution in the frequency range from 4000 cm−1 to 400 cm−1. Crystal structure of the samples was analyzed by a Bruker X-ray diffractometer (D8 ADVANCE, Germany, Ni-filter, Cu Kα AR-C 66096 λ=0.15418 nm). The superhydrophilicity of the films was evaluated by water contact angle (WCA) measurements with an OCA40 contact angle goniometry from Dataphysics Co. Germany. Typically, the average value of five measurements, made at different positions of the film surface was adopted as the value of WCA. The fraction of the liquid–solid interface in Cassie model was established with the image processing technique, i.e., apical meristem was supposed that the interface corresponds to the top parts among pores. Samples for antifogging behavior test were prepared by the washed glass substrate (2.5 cm×3.5 cm) coated with A3 (porous) film at the same condition. Boiling water was added into a beaker. The sample was placed on the beaker with coated surface facing down for 5 min. Vapor condensed on the porous TiO2 film coated surface was observed and photographed.