Large-Scale Preparation of Durable VO2 Nanocomposite Coatings

Vanadium dioxide (VO2) glass is a promising thermochromic smart energy-saving window. Many studies have been carried out for improving its optical performance, but for practical applications, the weatherability and large-scale preparation still remain as obstacles. In this work, the failure mechanism of VO2 nanoparticles at room temperature was analyzed, a new formulation of the VO2 nanocomposite coatings was designed to improve the coatings' weatherability, and a continuous roll-coating method was developed for large-scale preparation. The process is an all-solution-based low-temperature (240 degrees C) method and has no specific requirements for atmosphere. The size of the samples prepared using the current method is as large as 1.2 x 1.0 m(2). The prepared samples showed significantly improved weatherability compared to a reported water system (sixfold increase in moisture resistance test), excellent optical performance with a phase-transition temperature of 30 degrees C (T-lum = 55.0 % (10 degrees C) and 51.0 % (70 degrees C) and Delta T-sol = 16.6%), and phase-transition stability (less than 5% performance loss after 7000 cycles).

Automated summary

This study analyzed the failure mechanism of VO2 nanoparticles at room temperature, designed a new formulation for VO2 nanocomposite coatings to improve weatherability, and developed a continuous roll-coating method for large-scale preparation.