Dual-Functional Interfacial Engineering of Aramid-Based Composite Films as High-Performance Thermal Interface Materials

The development of thermal interface materials (TIMs) is pivotal for addressing thermal management challenges in advanced electronic systems. While the aramid nanoribbon (ANR) films exhibit exceptional in-plane thermal conductivity (k∥), their out-of-plane thermal conductivity (k⊥) remains constrained by inherent structural anisotropy. To overcome this limitation, nanodiamond (ND) fillers are incorporated into the ANR matrix. The polydopamine (PDA) surface modification realizes dual-functional interfacial engineering: (i) suppressing ND agglomeration through enhanced electrostatic repulsion to achieve uniform filler dispersion; (ii) forming hydrogen bonds at the interfaces between ANR and ND to reduce interfacial thermal resistance. The ANR/ND@PDA film exhibits a k⊥ of 0.45 W/(m·K) and a k∥ of 16.85 W/(m·K), representing 462.5% and 879.7% increase, respectively, compared to the pristine ANR film. A practical test to assess the performance as a thermal interface material (TIM) is performed by observing light-emitting diode (LED) heat dissipation, highlighting immediate and rapid heat dissipation achieved with the ANR/ND@PDA film. Multiscale simulations, including molecular dynamics (MD) and finite element analysis (FEA), quantitatively investigate the roles of hydrogen-bonded interfacial interactions and uniform filler distribution in facilitating heat transfer. These findings position the ANR/ND@PDA films as high-potential polymer-based TIM candidates for next-generation thermal management applications.