We all know that dark object absorb heat while white one reflect them. This presents an issue when it comes to a roof on a house. But what if you could have you cake and eat it too? This new material will change color, from white to black and back again, depending on the temperature. You can have a white roof during the summer and a black one during the winter! This could do wonders for your heating and cooling costs.
When the polymer phase separates from the gel, the solution becomes a mixture of polymer and solvent and because the polymer and solvent have different refractive indices the mixture becomes strongly scattering (white colored). When the mixture cools below the transition temperature the polymer re-dissolves in the liquid and the solution is clear and colorless. The pictures below illustrate the change in color when the tile is subjected to hot and cold temperatures.
This technology recently took first place in a competition, the school that won? MIT. Check the full story here