Figure 2From: Effect of annealing temperature on wettability of TiO2 nanotube array filmsSEM images of TN films (a) unannealed and annealed at (b) 200°C , (c) 400°C , (d) 600°C , and (e) 800°C . The insets are optical images of water droplets on the sample surface, during the WCA measurement.Back to article page