Polymer-Encapsulated TiO2 for the Improvement of NIR Reflectance and Total Solar Reflectance of Cool Coatings

Cool coatings are solar reflective coatings and are applied on roofs, facades, and other exterior surfaces. In this work, the effect of polymer encapsulation was investigated aiming to improve near-infrared (NIR) reflectance of cool coatings. Cool coatings formulated using polymer-encapsulated TiO2 resulted in improvement (up to 10%) of NIR reflectance and, therefore, total solar reflectance in comparison to the coatings formulated using bare TiO2, especially in a high pigment volume concentration system. This is mainly due to the TiO2-TiO2 spacing and improved light scattering from the coating films. Enhanced cooling (2.5-11.2 degrees C) was also observed during heat buildup measurement tests conducted both in the lab under an artificial IR light source and at outdoor conditions under natural light.