Session: K9-05: RADIATIVE COOLING AND RADIATIVE PROPERTIES OF NANOMATERIALS

Paper Number: 142391

142391 - Significance of Nanostructure and Morphology in Radiative Cooling Nanocomposites 

Abstract: 

The fight against global warming has necessitated the exploration of innovative approaches to address the rising global temperatures. Radiative cooling, a passive method utilizing materials to reflect sunlight and emit heat into deep space, presents a promising solution. The structures and compositions of materials play a crucial role in their performance, and we aim to investigate the effect of composite structure and particle shape. For example, calcium carbonate is a material seen in both cooling paints and snail shells for cooling purposes but with nanoparticle and multilayer morphologies, respectively. In this study, we assessed the optical performance of calcite-air nanolayer and nanosphere composites using the Transfer Matrix Method and Mie theory in conjunction with Monte Carlo simulation, respectively. It is remarkable that the nanolayer composite demonstrates the highest reflectance and is most efficient at a nanolayer thickness of 300 nm. Conversely, spherical nanoparticles achieve their peak reflectance at diameters ranging between 500 and 600 nm. Furthermore, we designed and fabricated lightweight hBN-Acrylic nanoporous paints that exhibited high solar reflectance, sky window emissivity, and daytime sub-ambient cooling. This work is based on the unique properties of hBN nanoplatelets showing Mie scattering-like high scattering coefficient and having Rayleigh scattering-like strong backscattering simultaneously. These findings underscore the distinctive characteristics of each nanoparticle morphology and emphasize the necessity for tailored optimized parameters to attain optimal solar reflection.

Presenting Author: Ioanna Katsamba Purdue University

Presenting Author Biography: Ioanna is a Ph.D. student at the School of Mechanical Engineering of Purdue and a research assistant at the Sustainable Energy and Nanoscale Transport Laboratory, working under the supervision of Professor Xiulin Ruan. She received her B.S. and M.S. in Mechanical Engineering and Manufacturing from the University of Cyprus in 2017 and 2019. Her research interest is in optical and transport phenomena in nanomaterials.

Authors:

Ioanna Katsamba Purdue University
Krutarth Khot Purdue University
Andrea Felicelli Purdue University
Xiulin Ruan Purdue University