Solar heat reflective glass by nanostructured sol–gel multilayer coatings

New 3-layer near-infrared reflective glasses were prepared by coating clear float soda-lime glass with nanostructured TiO2 and SiO2 films using a dip coating technique. Reflective interference filters at NIR region (800–1000 nm) were designed by simulation and prepared onto 4 mm clear glass. Optical, microstructural and mechanical properties were determined for the coated glasses. 3-layer sol–gel glasses show high visible transmittance >70% combined with high solar reflectance about 30% (with reflectivity up to 60% at region from 800 to 950 nm) and high UV blockage (transmittance <35%). Due to good abrasion resistance of the filters, application for monolithic windows in automotive and architectural areas is promising.

► Series of 3-layer dipping sol–gel interference filter based on TiO2/SiO2/TiO2 were designed and prepared.
► Outstanding combination of high visible transmission and solar blockage was achieved, showing Tuv < 35%, Rs ∼ 30%, TL > 85%.
► It was shown that the morphology of TiO2 films closely depends on the experimental conditions and titania thickness.
► The samples presented good abrasion resistance, acceptable for its practical application.