earticle

영어

This study compares the optical and radiative cooling performance of single-layer films embedded with TiO2 or Al2O3 nanoparticles dispersed in a polymer matrix and backed with an aluminum reflector. Optical constants of both materials were obtained from literature, and wavelength-dependent scattering efficiencies were calculated using Mie theory. A Monte Carlo ray-tracing simulation was performed to evaluate the spectral reflectance, absorptance, and emissivity of each film across the solar and thermal-infrared regions. The TiO2-based film exhibited strong visible-light scattering but suffered significant ultraviolet (UV) absorption, resulting in an average solar reflectance of ~0.90. In contrast, the Al2O3-based film showed negligible UV absorption and maintained high reflectance (>0.95) throughout the 0.3-2.5 μm solar band, leading to a higher net cooling power of approximately 105 W/m² compared to 85 W/m² for TiO2. These results demonstrate that UV reflectance is a key determinant of effective radiative cooling and indicate that Al2O3-based coatings offer strong potential for passive cooling applications in buildings and agricultural environments.