Constructing a “Pearl-Necklace-Like” architecture for enhancing thermal conductivity of composite films by electrospinning

With the integration level and power density of electronic devices increasing, highly thermally conductive yet electrically insulating polymer composites are growing demands for thermal management applications. Herein, we report a composite film with a “pearl-necklace-like” structure composed of polyvinyl alcohol (PVA) and alumina (Al2O3) by electrospinning technique, which exhibits enhanced high thermal conductivity, excellent electrical insulation, and outstanding flexibility simultaneously. The in-plane thermal conductivity of the PVA/Al2O3 composite film with 65 wt % Al2O3 loading reaches 31.69 W m-1 K-1. Meanwhile, the composite films still retained highly electrical insulation (volume resistivity 1.94 × 1011 Ω·cm) and presented excellent stability in a wide range of temperatures before and after heating and cooling cycles. This study provides a practical route to prepare the polymer composites with high thermal conductivity and excellent electrical insulation for thermal management applications in modern electronic devices.