An innovative strategy to enhance the interfacial interaction and effective contribution of BN in thermal conductivity in aramid based composites films

With the escalating concern over electronic device overheating, BN/polymer based thermal conductive composites have experienced remarkable growth in the field of heat dissipation. However, it is challenging to enhance the thermal conductivity of composites while preserving strong interfacial interaction due to the dilemma of chemical inertness of BN, interfacial thermal resistance and filler-polymer interaction. Herein, we utilized the adjustable surface charge of polydopamine under varying pH to fabricate composite films comprising polydopamine-modified boron nitride nanosheets and aramid sheets (BNNS@PDA/ANFS) by electrostatic assembly. The thermal conductivity of the composite rose to 36.9 W/m⋅K −1 with only 20 wt% filler. According to Density functional theory (DFT) simulation and interface thermal resistance calculation, the electrostatic assembly enhanced interface interactions and greatly reduced thermal resistance barrier. Furthermore, the optimal tensile strength of 304 MPa, is 2.32 times higher than pure ANFS film, accompanied by toughness of 33.2 MJ/m −3 . These superior performances are the results of a synergistic strategy, combining interfacial and topological enhancements. This work provides an innovative approach to enhance effective filler contribution in matrix and underscores the significant potential of BNNS@PDA/ANFS composite films in applications related to heat management.