Control of thermal barrier performance by optimized nanoparticle size and experimental evaluation using a solar simulator

•The objective of this study is to evaluate the thermal barrier performance of a pigmented coating with a dark appearance.•CuO pigmented coating was optimized by a theoretical design method.•The spectral reflectance was measured using spectroscopy in the visible (VIS) and near-infrared (NIR) regions.•The temperatures of the designed coatings and typical black paints are measured in a solar simulator.•The temperature measurement was simulated by numerical analysis.

An experimental investigation to evaluate the radiative properties of a selectively transparent thin coating on a substrate of a different material has been performed in order to evaluate its thermal behavior for applications where a low temperature at the surface exposed to the sun is desired. Copper (II) oxide (CuO) micro-particles have been used to create a pigmented coating on a paper substrate. The particle volume fraction and size have been optimized by the theoretical methodology. The spectral reflectance was measured using spectroscopy in the visible (VIS) and near-infrared (NIR) regions. The spectral emissivity was evaluated from the reflectance in IR region. The temperatures of the designed coatings and typical black paints are measured in a solar simulator. The temperature measurement was simulated by numerical analysis. The temperature of CuO coating on standard white paper was 10 °C lower than the ones of typical black paint while keeping the desired dark tone.