But in applications that have precise size and weight requirements, the paint needs to be thinner and lighter.” That’s why Ruan’s team began experimenting with other materials, pushing the limit of materials’ capability to scatter sunlight.This new paint achieves nearly the same benchmark of solar reflectance (97.9%) with just a single 150-micron layer of paint.“Hexagonal boron nitride has a high refractive index, which leads to strong scattering of sunlight,” said Andrea Felicelli, a Purdue PhD student in mechanical engineering who worked on the project.“The particles of this material also have a unique morphology, which we call nanoplatelets.” Ioanna Katsamba, another PhD student in mechanical engineering at Purdue, ran computer simulations to understand if the nanoplatelet morphology offers any benefits.The research was performed at Purdue’s FLEX Lab and Ray W. Herrick Laboratories and the Birck Nanotechnology Center of Discovery Park District at Purdue."