Synergistic effect of dual-modification strategy on thermal conductivity and thermal stability of h-BN/silicone rubber composites: Experiments and simulations

This study aims to investigate the effect of the modification strategy of hexagonal boron nitride (h-BN) on the interfacial heat transfer behavior of the composite. Dual modification of h-BN, including covalent and non-covalent modifications, was achieved by combining 6-aminohexanoic acid (ACA)-assisted wet ball milling and tannic acid (TA) surface deposition. Molecular dynamics (MD) simulations show that the interfacial thermal resistance of the covalently modified and the non-covalently modified regions of the composite system is reduced by 19.7 % and 40.9 %, respectively, and the interfacial thermal conductivity is increased by 24.5 % and 88.0 %, respectively. Meanwhile, thermogravimetric analysis demonstrated a 9 °C and 23.7 °C increase in the maximum weight loss temperature of the dual-modified composites compared to that of the two single-modified composites. The synergistic mechanism of the dual modification strategy in improving the interfacial interaction and enhancing the phonon vibration power spectrum of the composites is revealed by MD simulations. This study contributes to a deep understanding of the thermal conductivity mechanism of filled thermal interface materials. It guides the design of modified filler-filled high thermal conductivity rubber-based composites.