A hierarchical metafabric with dynamically thermochromic property for subambient daytime radiative cooling

Abstract

Reconciling optimal cooling effects with color regulation in functional textiles, while preserving infrared characteristics, remains a formidable technological challenge. Here, a novel dynamically hierarchical metafabric is reported that integrates temperature-adaptive thermochromic and moisture-wicking functionalities into a passive radiative cooling system, which effectively achieves energy-efficient personal thermal management. The objective was achieved by employing a hierarchically organized metafabric, which utilized the techniques of electrospinning and facile spray coating. Specifically, the metafabric is composed of polyamide 6/silicon dioxide/thermochromic chameleon microcapsules/hygroscopic agent layers. The metafabric demonstrates excellent selective infrared emissivity (0.95 in the 8–13 μm wavelength range) and moisture permeability through large-scale electrospinning and hierarchical design, while simultaneously maintaining superior mechanical strength. Specifically, the incorporation of thermochromic microcapsules facilitates reversible color alteration and self-adaptive modulation of solar energy (ΔR_lum = 52.64%), which significantly expands the potential applications for energy-saving thermoregulation. The resulting metafabric exhibits exceptional outdoor thermoregulation capabilities, demonstrating a cooling effect of 7.9 °C compared to commercial cotton in an outdoor environment under solar intensity of approximately 40 mW cm⁻². This study presents promising potential for the development of advanced personal thermal management systems with exceptional thermoregulatory capabilities, which could have significant implications in various fields such as wearable technology and medical devices.