Dual-window emissive radiative cooling textiles with a PTFE/SiO2 bilayer coating for enhanced thermal management

Abstract

Radiative cooling textiles are increasingly recognized as an effective strategy for energy-efficient thermal regulation. In this study, we present a novel radiative cooling textile, PTFE/SiO₂@Cotton, fabricated through in-situ synthesis of silica particles on cotton fabric followed by a polytetrafluoroethylene (PTFE) coating. The in-situ growth of SiO₂ nanoparticles significantly improved the durability of the fabric, ensuring long-term stability under various environmental conditions. The designed two-ply structure, which utilized the difference in refractive indices between PTFE (n = 1.29) and SiO₂ (n = 1.47), enhanced the backscattering of sunlight, resulting in a remarkable solar reflectance of 80.2 % in the visible light range (0.2–2.5 µm). The PTFE/ SiO₂@Cotton fabric exhibited high emissivity in both the first (8 ∼ 13 µm) and second (16 ∼ 25 µm) atmospheric windows, with an average emissivity of 97.8 % in the 4 ∼ 25 µm range. This dual-window emission provides effective radiative cooling in both dry and humid climates, making it adaptable to a variety of environmental conditions. Under simulated sunlight, the PTFE/ SiO₂@Cotton fabric demonstrated a temperature reduction of up to 11 °C compared to unmodified cotton fabric. Outdoor experiments further validated the cooling performance of the fabric, showing a temperature reduction of approximately 5 °C under peak solar irradiance (∼900 W/m²). In addition, the fabric had excellent UV resistance (UPF 186.8), self-cleaning properties, and washability, making it a practical solution for personal and architectural radiant cooling applications. This work provides a scalable and cost-effective approach to radiative cooling textiles, with significant potential for real-world implementation in diverse climatic conditions.