TiO₂/antimony-doped tin oxide : highly water-dispersed nano composites with excellent IR insulation and super-hydrophilic property

Abstract

In this work, a novel aqueous self-dispersed TiO₂ is synthesized and then used to produce the highly water-dispersed ATO/TiO₂ composite particles, which has strong IR insulation property. Thus, it can be used to block the solar radiative heat transfer in a building. The primary particle size of ATO/TiO₂ composites detected by TEM ranges from 5 to 12 nm, but that of the initial ATO nano particles is more than 2 µm. A small amount of TiO₂ (16.7% wt) increases the Zeta potential in water from 6.7 to 37.01 mV, which represents the stability is largely enhanced. The IR transmittance in IR band is decreased from 91% (original glass) to 4.3% (ATO 83.33% wt). The thermal performances of glass with such coatings are simulated based on Hong Kong climate situation. For the best sample, the electricity used in air-conditioning and lighting is 27% less than uncoated glass. Furthermore, the TiO₂ makes the water contact angle of the coating ranging from 3 to 5.6°. Therefore, the coating film can be prevented from fouling due to super-hydrophilicity and have a longer life time.