Affiliations 

  • 1 School of Chemistry and Materials Science, Jiangsu Key Laboratory of New Energy Devices & Interface Science, Nanjing University of Information Science & Technology, Ning-Liu Road 219, Nanjing 210026, China
  • 2 Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, China
  • 3 School of Engineering and Technology, Sunway University, Bandar Sunway, Petaling Jaya 47500, Malaysia
PMID: 39834073 DOI: 10.1021/acsami.4c22615

Abstract

Radiative cooling, a passive cooling technology, functions by reflecting the majority of solar radiation (within the solar spectrum of 0.3-2.5 μm) and emitting thermal radiation (within the atmospheric windows of 8-13 μm and 16-20 μm). Predominantly, synthetic polymers are effectively utilized for radiative cooling while posing potential environmental hazards due to their complex components, toxicity, or nonbiodegradation. Bacterial cellulose, a natural and renewable biopolymer, stands out due to its environmentally friendly, scalability, high purity, and significant infrared emissivity. In this work, we developed a bacterial cellulose-based composite film (BCF) with a cross-linked network structure by a facile agitation spraying method to achieve enhanced and sustainable radiative cooling performance. The BCF exhibited superior optical properties and environmental tolerance, with a notable infrared emissivity of 94.6%. As a result, the thermal emitter demonstrates a substantial subambient cooling capacity (11:00 to 13:00, maximum drop of 7.15 °C, average drop of 4.85 °C; 22:00 to 2:00, maximum drop of 2.7 °C, average drop of 2.32 °C). Additionally, the BCF maintained stable emissivity after 240 h of continuous UV irradiation. Furthermore, BCF can effectively preserve the freshness of fruits under intense solar irradiation. Hence, BCF with high radiative cooling performance presents a broad application prospect in building energy conservation, solar cells efficiency enhancement, and food transportation packaging.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.