SiC-doped thermochromic microcapsules with photothermal effect for thermal-regulating fabrics

Various thermal management materials designed for heating and cooling have been developed to achieve all-season thermal regulation. However, creating a thermal management system with zero energy consumption remains a challenge. This study presents novel thermal-regulating fabrics (TRFs) based on silicon carbide (SiC)-doped thermochromic microcapsules, which exhibit color change properties. The microcapsules, with a core-to-shell ratio of 2:1, demonstrate a high contrast in color change. The incorporation of SiC not only enhances thermal conductivity and photothermal properties but also mitigates the supercooling phenomena observed in microcapsules. The enthalpy of melting for the microcapsules containing 2 % SiC was measured at 104.5 J/g, indicating a significant thermal storage capacity. Polydimethylsiloxane (PDMS) containing 40 wt% microcapsules was screen-printed of onto the surface of cotton fabrics to create the TRFs, which can automatically switch between black and white as temperature changes, leading to notable alterations in optical properties. Specifically, the TRFs appear white with high reflectance at elevated temperatures, while they transition to black below 20 °C, activating a heating mode. The thermal-regulating fabrics, which allow for modifiable solar absorption, offer a novel approach to the development of intelligent thermal management materials, demonstrating significant potential for creating comfortable personal environments.