Preparation and Characterization of ATO/PS Bilayer Films with Superior Hydrophilicity

The hydrophilic films are widely used in industrial and domestic fields. Here, we report a Tin oxide film doped with antimony and Potassium silicate (ATO/PS) hydrophilic bilayer films deposited on aluminum substrates. The ATO film was prepared first on the substrates by spray pyrolysis and then PS film was deposited on ATO film by a simple dip-coating method. The structure, morphologies, wettability, stability of hydrophobicity and thermal conductivity of four kinds of samples have been analyzed in detail, including Al substrates (Al), Al substrate with ATO film (ATO), Al substrate with PS film (PS) and Al substrate with ATO/PS bilayer films (ATO/PS). The results show that the hydrophobicity of ATO/PS bilayer films is superior with contact angle of 12.5°. And the angle of ATO/PS sample is approach to 20° after being immersed in water for 48h, while 44.5° is obtained for the PS sample. The thermal conductivity value of ATO/PS sample is almost the same as the Al substrate, and also better than PS film. These results indicate that ATO/PS bilayer films have potential application in heat exchanger and other heat dispersing fields.