Israel’s Nano Z-Tech is developing nanocoating technology that protects many surfaces from liquid spills or rainwater, with diverse uses. It also allows visible light to penetrate roofs and windows, but not infrared light (heat energy), which makes NASA very interested in the product.
http://www.globes.co.il/en/article-nano-z-tech-nanocoatings-protect-fabric-metal-and-glass-1000939442