Multifunctional Polymeric Architecture as UV‐Shielding Thermo‐Sensor for Smart Window and Security Applications

Abstract In this study, the development of a novel thermoresponsive UV‐shielding [poly(methyl acrylate) ₁₀₀ ‐ block ‐poly( tert ‐butyl methacrylate) ₅₀ ‐ block ‐poly(2‐(dimethylamino)ethyl methacrylate) ₂₀₀ ]‐umbelliferone (PMA ₁₀₀ ‐ b ‐PTBMA ₅₀ ‐ b ‐PDMAEMA ₂₀₀ ‐UMB) triblock copolymer with dual thermo and UV‐active functionality is reported for the fabrication of thermally switchable smart window and utilization as invisible fluorescent ink (suitable for security applications). The material demonstrates excellent thermal responsiveness, enabling reversible transparency modulation based on external temperature changes. This property makes it ideal for energy‐efficient smart window application by dynamically controlling light and heat transmission. Additionally, the polymer exhibits exceptional UV‐shielding performance, effectively blocking harmful UVA (320–400 nm) and UVB (280–320 nm) radiation while maintaining optimal optical clarity. Furthermore, its unique optical responsive, including invisibility under natural light and luminescence under UVA ( λ _max = 352 nm) illumination, make it suitable for advanced information security applications. Detailed investigations of the photophysical properties of material reveal a precise coil‐to‐globule transition due to its thermoresponsive behavior, alongside robust UV‐blocking capabilities. This multifunctional material represents a significant step forward in the development of sustainable, high‐performance polymers for smart coatings, energy‐efficient technologies, thermo‐sensors, and secure information storage.