Toyota Central R&D Laboratories, Inc., 41-1 Yokomichi, Nagakute 480-1192, Japan.
ACS Appl Mater Interfaces. 2023 Apr 19;15(15):19427-19434. doi: 10.1021/acsami.3c00397. Epub 2023 Apr 6.
A scalable and durable thermochromic composite is developed for temperature-adaptive solar heat management using a carbon absorber and a thermoresponsive polymer blend consisting of an isolated polycaprolactone phase (PCL) and a continuous phase of miscible poly(methyl methacrylate) and polyvinylidene fluoride. The ternary blend exhibits reversible haze transition originating from the melting and crystallization of PCL. The refractive index matching between the molten PCL and surrounding miscible blend contributes to high-contrast haze switching in the range of 14-91% across the melting temperature of PCL (ca. 55 °C). The solar-absorption-switching properties of the composite are due to the spontaneous light-scattering switching in the polymer blend and the presence of a small amount of carbon black. Spectral measurements indicate that the solar reflectance of the composite sheet varies by 20% between 20 and 60 °C upon lamination with a Ag mirror. Solar heat management using the thermochromic composite is successfully demonstrated under natural sunlight, thereby realizing a temperature-adaptive thermal management system.
一种可扩展且耐用的热致变色复合材料，使用碳吸收剂和由隔离的聚己内酯相 (PCL) 和可混溶性聚甲基丙烯酸甲酯和聚偏二氟乙烯的连续相组成的热响应聚合物共混物开发，用于自适应太阳能热管理。三元共混物表现出源自 PCL 熔融和结晶的可逆雾度转变。在 PCL（约 55°C）的熔融温度范围内，熔融 PCL 和周围可混溶共混物之间的折射率匹配有助于在 14-91%的范围内实现高对比度雾度切换。复合材料的太阳能吸收切换特性归因于聚合物共混物中的自发光散射切换以及少量炭黑的存在。光谱测量表明，复合片在与 Ag 镜层压时，其太阳能反射率在 20 至 60°C 之间变化 20%。使用热致变色复合材料的太阳能热管理在自然光下成功得到演示，从而实现了温度自适应热管理系统。
