Preparation Of Highly Stable Nano-ATO Slurry And Transparent Thermal Insulation Coating

Transparent and thermal-insulation nano coating has a wide application in thesociety especially in glass curtain wall. Despite of its promising future, thedisadvantages of the coating such as poor stability of nano-slurry, low transparencyand high cost prevents its farther development. This paper will focus on the researchof the stability of nano-slurry and the formula of the coating to solve the poorperformance of the coating. The specific measurement results are as follows:In order to prepare the highly stable aqueous suspensions of antimony-doped tinoxide (ATO) used for the transparent and thermal insulation fluorocarbon coating,the effect of pH and dispersants on the stability of the suspensions was investigated.The stability and dispersity of the suspensions were characterized using zetapotential analyzer, ultraviolet-visible spectrophotometer and scanning electronmicroscope. No sediments were observed after six-month storage of the ATOsuspensions containing0.1wt.%sodium polyacrylate (PAAS) and2.0wt.%polyvinyl alcohol (PVA) with the pH of10.0. Transmittance of the slurry was only0.01%after centrifuged for ten minutes at3000rpm and diluted five times withdistilled water. The average diameter of ATO in slurry was107.5nm and itspolydispersity index value was only0.123. It demonstrated the good stability of theslurry with binary dispersants. The reason why aqueous suspensions were capable ofstabilization was explained from a theoretical perspective. A new model of sterichindrance for colloid particles stabilized by binary dispersant was proposed.The effects of coalescing agent and flatting agent on the transmittance of thecoating was investigated for the sake of improvement in transmittance of the coating.The experimental result shows that the minimum film forming temperature hasdecreased10°C when coalescing agent CZ-12was added to1.0wt.%. As a result, thetransmittance of the slides with coating was increased from61.3%to75.8%in600nm wavelength. When the coating containing0.5wt.%flatting agentpolyurethane-2020, the transmittance of the slides with coating was increased from76.4%to75.8%in600nm wavelength. The temperature inside the chamber wasdecreased by6.0°C and average75.0%visible light rays could pass through theordinary float glass coated nano-composite fluorocarbon coating. In conclusion, anano-composite fluorocarbon coating, exhibiting a good thermal insulation, hightransmittance and excellent mechanical properties, was formed after ATOsuspensions were added in fluorocarbon emulsion.