City skylines around the world are increasingly dominated by tall buildings constructed with thickglass panels – but nanostructures that show extreme water repellency could help to combat the heating, cooling, and cleaning costs of maintaining these iconic, glazed facades.
In my project I create surfaces that contain millions of structures (pillars or cones), which are approximately 1,000x smaller than the width of a human hair. Water hates being in contact with these nanostructures, as they are known.
When a water droplet hits the surface, it immediately bounces or rolls off. As the droplet rolls off the surface, it picks up any dust along the way, which results in a “selfcleaning” surface that is excellent for windows. In addition to the water repellent properties, I am also looking to coat the nanostructures with materials that are thermoresponsive – where the properties change due to heat. And so the selfcleaning windows become "smart" windows that are able, without energy, to control the heat going into and out of a glass skyscraper depending on the outside temperature.
A change to the size and distance between the nanostructures has a significant effect on the overall surface properties. Decreasing the distance between the structures, for instance, can generate a surface that is not only selfcleaning but also antireflective.
Antireflective surfaces are ideal for solar cells as they reduce the amount of reflected light, thereby increasing the energy efficiency of the solar cell – which in turn could make the heavy costs associated with glass skyscrapers easier to manage.
