Efficient refinement and stable dispersion of ATO nanoparticles mediated by polyethyleneimine for spectral selective energy-saving window

Antimony tin oxide (ATO) holds great promise as a transparent conductive oxide in near-infrared insulation applications. Reducing the particle size of ATO and improving its uniform dispersion are the key problems to be solved in preparing thermal insulation windows with excellent spectral selectivity. The post-synthetic dispersion of ATO is particularly challenging. This study introduced branched polyethyleneimine (PEI) as a novel dispersant for ATO. Through ball milling in ethanol, PEI's chelation and spatial stabilization efficiently reduced the average particle size of ATO to 26.7 nm. The resulting ATO ethanol dispersion demonstrated superior long-term storage and centrifugation stability. Compounding the dispersion with polyvinyl butyral (PVB) yielded ATO/PVB coatings, which exhibited the superior near-infrared shielding efficiency while maintaining a high visible transmittance and a low haze. Subsequently, the ATO/PVB coating exhibited excellent thermal insulation properties, reducing the temperature rise by 17.2°C compared to blank glass after 10 minutes of irradiation with a NIR lamp. The work demonstrates the potential of the coating for efficient energy-saving window applications. • Branched PEI as the dispersant for efficient ATO dispersion. • The 10 % PEI imparts excellent stability to the ATO ethanol dispersion. • The mechanism of dispersion and stabilization of PEI to ATO was proposed. • ATO/PVB coatings with fine ATO exhibit great thermal insulation and visual clarity.