Abstract:

Significance With the rapid development of modern industry, too much energy was consumed for temperature regulation, which leads to serious environmental problems. For example, the excessive consumption of fossil fuels to achieve space cooling, large greenhouse gas emissions, and the difficult degradation of condensing ice packs will bring a series of environmental problems and survival problem. The conventional cooling system is more complex and the service life of the equipment is short. In contrast, radiation cooling technology achieves cooling on its own without consuming more external energy. Therefore, the emergence of radiation cooling materials has brought light to the realization of sustainable low-carbon models and the development of products that are beneficial to human comfort. Based on the mechanism of radiative cooling, this paper introduces radiation cooling technology, classifies radiation cooling materials, analyzes the application of existing radiation cooling materials in different fields, and finally summarizes the challenges and development of radiation cooling technology.

Progress The spectral selectivity regulation of radiation cooling materials is the key to achieving efficient thermal management. Current material design mainly focuses on optimizing the infrared emission performance of materials in the atmospheric window band (8-13 μm), enhancing the solar reflection characteristics in the solar spectral band (0.3-2.5 μm), and achieving dynamic regulation of spectral properties through micro-nanostructure engineering. In order to achieve this goal, researchers adopted a combination strategy including multi-scale porous structure construction, functionalized multilayer film composites, and precise doping of nanoparticles, ultimately achieving a synergistic optimization of high reflectivity in the solar spectrum and high emissivity in the mid-infrared band. In recent years, significant progress has been made in the research of radiation cooling materials, and their applications have been expanded to multiple fields such as building energy conservation, cold chain logistics and renewable energy. In the field of textiles, technological research and development are evolving from a single thermal management function to a multi-functional integration direction. The new generation of smart textiles, by integrating functions such as antibacterial, flame-retardant and ultraviolet-resistant properties, have expanded their application scenarios beyond personal thermal management, and demonstrated unique advantages in special fields such as fire-fighting equipment, military protection and aerospace. In terms of building materials, technological evolution has undergone a leap from basic cooling functions to composite performance. Modern radiation cooling building materials possess excellent weather resistance, self-cleaning performance and low light pollution characteristics. Applications of agricultural cold chain has initially met the demand for the preservation and transportation of fresh food. Radiation cooling materials are transforming from single-function to multi-functional integration, and their development shows obvious characteristics of diversification, integration and practicality.

Conclusion and Prospect In the future, radiation cooling materials will focus on the development of low-cost, high-performance, green and degradable cooling products. In order to achieve the large-scale application of radiation cooling materials, the cooling efficiency of materials should be significantly improved, the production process of materials should be simplified, and the functions of materials should be broadened. At the same time, in terms of structural design and material selection, the aging resistance and hygroscopic properties of the material should be fully considered to achieve multi-functional integration. In addition, the use of radiation cooling materials is mainly to reduce energy consumption and achieve green refrigeration, and more degradable radiation cooling materials should be developed. Finally, for the current research on radiation cooling materials, its application range and cooling performance evaluation mostly stay in the laboratory stage, and it should be based on the use of scenarios and actual needs, to strengthen the correlation and systematization of radiation cooling and other materials and improve the overall cooling performance evaluation of radiation cooling materials. With the development of the times and market demand, radiation cooling materials should not be limited to textiles, buildings and agriculture fields, and the textile field will be followed by intelligent cooling technology, and research with thermal comfort adjustment and sensory interaction functions of cooling textiles.

Key words: radiation cooling technology, radiation cooling material, radiation cooling materials for textiles, radiation cooling material for building, radiation cooling material for agricultural use