Song Yan-Lin lab from the Institute of Chemistry of the Chinese Academy of Sciences, together with Li Ming-Zhu lab from the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences, designed a structurally colored radiative cooling film with a hierarchically porous nested structure (SC-RC film), which can preserve highly efficient subambient cooling performance and provide an appealing colorful appearance.

The SC-RC film is engineered to reflect sunlight across a broad range of wavelengths while exhibiting distinct reflective peaks at specific wavelengths. Resulting in brilliant structural colors without compromising cooling efficiency. The color can be adjusted by altering the diameter of colloidal nanoparticles.

The innovative design embeds colloidal photonic crystals into micropits, ensuring a confined assembly of nanoparticles and reducing defects associated with self-assembly. This process results in vibrant structural colors. Additionally, the PMMA micropit framework provided protective support for colloidal photonic crystals that significantly enhanced the mechanical stability of the structural colors.

The production techniques used to create the SC-RC film-nanoimprinting, phase separation, and self-assembly—are simple and scalable, making it suitable for a wide range of applications, from urban architecture to vehicles.

The SC-RC film showed excellent radiative cooling performance. cooling surfaces by an impressive 21.2°C in sunlight, outperforming commercial-colored films. This breakthrough technology merges functionality with visual appeal, paving the way for a future where energy-efficient cooling and aesthetics design coexist harmoniously.

This study was published in Matter(https://doi.org/10.1016/j.matt.2024.10.016). The research was supported by the National Key R&D Program of China , the National Science Fund for Distinguished Young Scholars, the National Natural Science Foundation of China, and the Bureau of International Cooperation, Chinese Academy of Sciences. 

The design and cooling performance of the SC-RC film. (Image by Li Mingzhu)

Contact:

Prof. SONG Yanlin

Institute of Chemistry, Chinese Academy of Sciences

Email: ylsong@iccas.ac.cn