Thermochromic hydrogel with high transmittance modulation and fast response for flexible smart windows
Fan Jiang (Kavli institute of nanoscience Delft, TU Delft - Fluid Mechanics)
Kui Yu (Kavli Institute of Nanoscience Discovery, TU Delft - BN/Marie-Eve Aubin-Tam Lab)
Roland Kieffer (TU Delft - BN/Marie-Eve Aubin-Tam Lab)
Djanick de Jong (TU Delft - BN/Marie-Eve Aubin-Tam Lab)
Richard M. Parker (University of Cambridge)
Silvia Vignolini (Max-Planck-Inst. F. Kolloid-und G., University of Cambridge)
Marie Eve Aubin-Tam (TU Delft - BN/Marie-Eve Aubin-Tam Lab)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Growing environmental concerns are driving demand for energy-saving strategies. Thermochromic smart windows offer a practical solution by passively regulating sunlight in homes and offices. Despite recent progress, current technologies still face challenges in achieving the thermal durability and mechanical robustness necessary for long-term use, combined with a rapid transition below 30 °C. Here we report a thermochromic hydrogel assembled from poly(N,N-dimethylaminoethyl methacrylate) and 2,2,2-trifluoroethyl methacrylate that produces flexible films on a large scale. This hydrogel rapidly (~ 3 s) and reversibly becomes turbid above a tunable transition temperature spanning the human comfort zone, and maintains its thermochromic property even when mechanically stretched with 500% strain. The film’s high modulation of solar transmittance (70.6%) and luminous transmittance (85.7%) enables efficient sunlight screening in hot weather and clear vision in cool weather. Such ‘smart windows’ remain stable for over 10,000 heating/cooling cycles. These combined features indicate the hydrogel suitability for applications ranging from heat-modulating smart windows (architectural, automotive, etc.) to passive temperature indicators and even wearables.
help_outline