Broadband Antireflective Superhydrophilic Thin Films with Outstanding Mechanical Stability on Glass Substrates

A facile approach was developed to fabricate visible/near-infrared antireflective (AR), superhydrophilic and anti-fogging thin films on glass substrates. Glass substrate was first etched by H2SiF6-based vapor and then dip-coated sequentially in a base-catalyzed 20 nm SiO2 nanoparticles sol and an acid-catalyzed SiO2 sol. After annealing, the prepared thin film (named E/BSiO2/ASiO(2)) not only showed good optical and wetting properties, but also exhibited excellent mechanical properties. The thin film has enhanced transmittance in the spectral range of UV to near-infrared. The maximum transmittance of E/BSiO2/ASiO(2) thin film coated glass substrate is 98.4% in 400-1200 nm and 96.1% in 1200-2500 nm, respectively. Comparing with blank glass substrate, the average transmittance increases by 5% in the wavelength range of 300-2500 nm. Meanwhile, the film showed good anti-fogging performance. SEM and AFM were employed to characterize the morphology of the thin film. The prepared thin film has potential application in various areas, like solar cells, windowpanes and eyeglasses, and may also find applications in membrane-based separation, selective catalysis and sensors.