Fabrication of highly transparent and superhydrophilic coatings on glass by modified α-zirconium phosphate nanoplatelets

Abstract

The synthetic α-zirconium phosphate (ZrP) modified by tetra-n-butylammonium hydroxide (TBA+OH−) was used to fabricate highly transparent and superhydrophilic coating on glass substrate through a facile and effective approach. The influence of molar ratio between TBA+OH− and ZrP on the surface topographical morphology, as well as the hydrophilicity and transparency of coating was explored. It was found that, the higher concentration of TBA+OH− is, the better surface wettability and light transmission performance are. With more introduction of TBA+OH−, more TBA+ ions can be intercalated into the ZrP interlayers to form exfoliated nanoplatelets, which are able to continuously cover the whole glass substrate as revealed by scanning electron microscopy and atom force microscopy. As a result, the contact angle of the prepared coatings can reach to ~4.5° at 400 ms and ~0° within 1 s. The completely exfoliated structure of ZrP nanoplatelets and high surface charge density provided by TBA+ ions make a great contribution to the highly transparent and superhydrophilic coatings on glass substrates. The detailed mechanisms on fabricating high-performance superhydrophilic coatings on glass substates by TBA+OH− modifying ZrP nanoplatelets are carefully elaborated.