Chen Wenqian, Lin Zequn, Hu Sheng
School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China.
ACS Appl Mater Interfaces. 2024 Dec 25;16(51):70863-70873. doi: 10.1021/acsami.4c14369. Epub 2024 Dec 12.
Thermochromic smart windows achieve energy conservation and emission reduction by regulating the energy exchange in buildings. However, their widespread application in architecture has been hindered by issues such as poor frost resistance, limited durability, high costs, recycling challenges, and suitability only for specific climates (such as tropical climates). To address these challenges, we have successfully developed a high-performance thermochromic window, which is an intelligent window based on a thermochromic solution of poly(vinyl alcohol) acetal and LiCl, encapsulated in a glass/thermal liquid/low-E structure. This thermochromic window exhibits scalability, frost-resistance, durability and all-climate adaptability (referred to as SFDA window, with the thermochromic liquid termed SFDA liquid). First, the SFDA liquid reported here utilizes an efficient one-pot aqueous synthesis technique to directly produce a polyvinyl acetal solution. This process not only supports large-scale production but also incorporates LiCl in situ, endowing the liquid with excellent frost resistance. Second, the concentration is purposefully adjusted to the entangled concentration to facilitate the sol-gel transition, ensuring durability during long-term use. Additionally, windows containing SFDA liquid demonstrate excellent performance, maintaining up to approximately 84% light transmittance and 70.7% solar radiation at 20 °C. Third, our SFDA window achieves high-efficiency energy savings compared to traditional thermochromic windows across all-weather conditions. Through indoor simulations, we found that SFDA window can cut energy consumption by 64.6% relative to traditional glass windows in the summer. In the winter, compared to traditional glass windows, windows containing SFDA liquid can reduce heating energy consumption by 52.3%. In simulations conducted across 33 cities worldwide, SFDA liquid windows achieved a total monthly energy savings of 1179.8 MWh compared to commercial Low-E window. With its outstanding energy efficiency, the SFDA smart window opens up a brand-new development pathway in the field of green economy.
热致变色智能窗通过调节建筑物中的能量交换来实现节能减排。然而，其在建筑领域的广泛应用受到了诸如抗冻性差、耐久性有限、成本高、回收利用挑战以及仅适用于特定气候（如热带气候）等问题的阻碍。为应对这些挑战，我们成功开发了一种高性能热致变色窗，它是一种基于聚乙烯醇缩醛和LiCl热致变色溶液的智能窗，封装在玻璃/热液/低辐射结构中。这种热致变色窗具有可扩展性、抗冻性、耐久性和全气候适应性（称为SFDA窗，热致变色液体称为SFDA液体）。首先，这里报道的SFDA液体采用高效的一锅水相合成技术直接制备聚乙烯醇缩醛溶液。该过程不仅支持大规模生产，还能原位掺入LiCl，赋予液体优异的抗冻性。其次，有意将浓度调节至缠结浓度以促进溶胶-凝胶转变，确保长期使用期间的耐久性。此外，含有SFDA液体的窗户表现出优异的性能，在20℃时保持高达约84%的透光率和70.7%的太阳辐射率。第三，与传统热致变色窗相比，我们的SFDA窗在所有天气条件下都能实现高效节能。通过室内模拟，我们发现SFDA窗在夏季相对于传统玻璃窗可降低64.6%的能耗。在冬季，与传统玻璃窗相比，含有SFDA液体的窗户可将供热能耗降低52.3%。在全球33个城市进行的模拟中，与商用低辐射窗相比，SFDA液体窗每月总共节省1179.8兆瓦时的能源。凭借其出色的能源效率，SFDA智能窗在绿色经济领域开辟了一条全新的发展道路。
