Scalable Film Based on Thermochromic and Radiative Cooling Effects for Anti-Counterfeiting and Low Temperature Preservation

Thermochromism and radiative cooling have received extensive attention as two popular research areas in recent years. However, how to effectively combine the two remains a challenge. Herein, we present a well-designed polymethylpentene (TPX)/silicon dioxide (SiO2)/thermochromic microcapsule (TSTM) hybrid film, which effectively integrates both thermochromic and radiative cooling capabilities. Notably, the thermochromic capability gives the TSTM film excellent anticounterfeiting performance by inducing a temperature-dependent change in solar transmittance. Furthermore, the TSTM film exhibits a high average infrared emittance (ˉεIR${\overline{\epsilon }}_{\mathrm{IR}}$) value of ∼94% at low temperatures and achieves a cooling effect exceeding 5C under a solar intensity (Isolar) of ∼900 W m–2, indicating an excellent radiative cooling property and potential for effective low-temperature preservation under sunlit conditions. Additionally, the TSTM film demonstrates outstanding durability, while a simple and straightforward fabrication process allows for large-scale production. Such a scalable, durable, and dual-functional hybrid film demonstrates an innovative and effective design, holding promise for expanding its application in the fields of anticounterfeiting and low temperature preservation.