Synergistic effects of boron nitride sheets and reduced graphene oxide on reinforcing the thermal conduction, SERS performance and thermal property of polyimide composite films

Polyimide (PI) composite films with hybrid fillers containing hBN (hexagonal boron nitride) sheets and rGO (reduced graphene oxide) were successfully fabricated by in-situ polymerization. Herein, hBN sheets and rGO were obtained by ball milling and chemical reduction, respectively. In PI composite films, hBN can be tightly attached onto the surface of rGO via pi-pi interaction, which can benefit the construction of heat-conduction pathways and reduce boundary of heat resistance. The results show that the addition of rGO and hBN could enhance the thermal conductivity by synergistic effects. Specially, hBN and rGO are at the weight ratio of 1:1 and at the total loading of 33 wt%, thermal conductivity of PI composites can reach up to 1.19 Wm(-1) K-1, which is 5.61 times higher than that of pure PI. Thermal property and dynamic mechanical property of composite films were also investigated. Besides, compared with pure PI, mixed fillers have obvious surface-enhanced Raman scattering signals, indicating the synergistic effect of the mixed fillers. Overall, this study gives insights into heat dissipative and high sensitivity analysis components which may be used in the field of high-temperature micro fabrication.