Water Desalination and Reuse Center, Division of Biological and Environmental Science and Engineering , King Abdullah University of Science and Technology , Thuwal 23955-6900 , Saudi Arabia.
ACS Appl Mater Interfaces. 2018 Nov 21;10(46):39819-39827. doi: 10.1021/acsami.8b15574. Epub 2018 Nov 6.
Smart windows with high near-infrared (NIR) light shielding and controllable visible light transmittance are highly sought after for cooling energy saving in buildings. Herein, we present a rationally designed spectrally selective smart window which is capable of shielding 96.2% of the NIR irradiation from 800 to 2500 nm and at the same time permitting acceptable visible light (78.2% before and 45.3% after its optical switching) for indoor daylighting. The smart window synergistically integrates the highly selective and effective NIR absorption based photothermal conversion of cesium tungsten bronze (Cs WO) with the transparent thermoresponsive poly( N-isopropyl acrylamide) (PNIPAM) microgel-polyacrylamide (PAM) hydrogel. Optical switching of the smart window is a direct result of the phase transition of PAM-PNIPAM hydrogel, which in turn is induced by the photothermal effect of Cs WO under sunlight irradiation. The smart window exhibits fast optical switching, shows long-term operational stability, and can be made highly flexible. Under the experimental conditions in this work, the indoor temperature with the smart window is ∼21 °C lower than that with a regular single-layered glass window under one sun irradiation. The smart window design in this work is meaningful for further development of effective smart windows for energy saving in the build environment.
具有高近红外（NIR）遮光和可控可见光透过率的智能窗户在建筑节能冷却方面受到高度追捧。在此，我们提出了一种合理设计的光谱选择性智能窗户，它能够屏蔽 800 至 2500nm 范围内的 96.2%的 NIR 辐射，同时允许可接受的可见光（光学切换前为 78.2%，光学切换后为 45.3%）用于室内采光。智能窗户协同集成了基于铯钨青铜（CsWO）的高选择性和高效近红外吸收光热转换，以及透明的热响应性聚（N-异丙基丙烯酰胺）（PNIPAM）微凝胶-聚丙烯酰胺（PAM）水凝胶。智能窗户的光学切换是 PAM-PNIPAM 水凝胶相转变的直接结果，而 PAM-PNIPAM 水凝胶相转变又是由阳光照射下 CsWO 的光热效应引起的。智能窗户具有快速的光学切换，表现出长期运行稳定性，并且可以高度灵活。在本工作的实验条件下，在一个太阳照射下，带有智能窗户的室内温度比常规单层玻璃窗低约 21°C。本工作中的智能窗户设计对于进一步开发用于建筑环境节能的有效智能窗户具有重要意义。
