High Thermal Conductivity and Biocompatibility Silk Fibroin Hydrogels Filled with CDs@BNOH for Body Surface Cooling

Abstract Efficient passive cooling technologies hold significant potential for applications in heat transfer, thermal conductivity, and energy concentration in high-power devices. However, common high-thermal-conductivity materials often suffer from poor biocompatibility and lack biodegradability, limiting their use in body surface cooling and wearable devices. Consequently, developing thermally conductive materials through green synthesis while ensuring biocompatibility and biodegradability has become a major challenge in body surface cooling. In this study, boron nitride particles modified with carbon quantum dots (CDs@BNOH) were synthesized as high thermal conductivity composite fillers, which were then incorporated into a potentially biocompatible silk fibroin hydrogel patch. The CDs@BNOH/SilMA patch exhibits a good and stable recyclable thermal conductivity of 0.77 W m–1 K–1, with a 15.38% increase in the overall thermal conductivity due to the modification with carbon quantum dots. Additionally, under simulated direct sunlight, the CDs@BNOH/SilMA patch demonstrated exceptional body surface cooling performance, reducing the temperature by 6.6 °C compared to the control group. This hydro patch not only exhibited potential biocompatibility and biodegradability but also demonstrated promising potential in body surface cooling applications.