Development of high‐performance silk‐based composite films with enhanced thermal conductivity and <scp>EMI</scp> shielding effectiveness

Abstract This paper presents the development of a high‐performance silk‐based polymer composite with enhanced thermal conductivity and electromagnetic interference (EMI) shielding capabilities. This composite achieved significantly improved thermal and electrical properties by incorporating 3‐(aminopropyl)triethoxysilane (APTES)‐functionalized reduced graphene oxide (rGO) and silver nanoparticles (AgNPs) into a silk nanofiber (SNF) matrix. The APTES surface treatment enhanced the chemical bonding between the filler–filler and filler–matrix interfaces, resulting in enhanced compatibility and dispersion, as well as the formation of effective conductive networks. Furthermore, the incorporation of AgNPs facilitated conductive bridging between the rGO sheets and the SNF matrix, thereby enhancing the continuity of thermal and electrical pathways. By employing an aerogel intermediate layer in conjunction with hot‐pressing techniques, a dense and compact structure with continuous conductive pathways was created. Owing to this synergistic approach, the SNF/f‐rGO@Ag composite achieved a high through‐plane thermal conductivity of 4.23 W/m·K and an EMI shielding effectiveness (EMI SE) of 59.1 dB. These properties render the composite well‐suited for applications in advanced electronic devices that require efficient thermal management and robust EMI shielding. Highlights APTES surface functionalization improves filler dispersion and compatibility. f‐Ag acts as a bridge between f‐rGO themselves and the SNF matrix. Aerogel intermediate contributes to the formation of continuous conduction pathways SNF/f‐rGO@Ag composite achieved 4.23 W/m·K through‐plane thermal conductivity. EMI shielding effectiveness of SNF/f‐rGO@Ag reached 59.1 dB, outperforming benchmarks.