Carbon nanofillers repair strategy for high-efficiency thermal conductivity enhancement of PBX composites at ultralow mass fraction

Owing to the existence of structural defects of nanofillers and interfacial thermal resistance, realizing high efficiency thermal conductivity (k) enhancement of polymer composites by high k fillers at low mass fraction has proven challenging. Here, aroused by the repair of natural spider web, we reported a novel strategy to mend the structural defects of carbon nanofillers (CNFs) via selective deposited of Ag nanoparticles. The morphology and microstructure of obtained CNFs@Ag were detailed characterized. With a filler loading of 0.5 wt%, a highefficiency k enhancement had been achieved. The k of PBX composites could reach to 0.722 W/mK, enhanced by 70% compared with pure PBX. Importantly, the temperature gradient and thermal stress distribution in PBX cylinder when facing complicated thermal changes were evaluated by finite element analysis. The study here sheds new light on enhancement of thermal conductivity of polymer composites which severely limits the content of fillers using.

Automated summary

This study successfully achieved high efficiency thermal conductivity enhancement by selectively depositing Ag nanoparticles to repair the structural defects of carbon nanofillers. The thermal stress distribution in PBX cylinder facing complicated thermal changes was evaluated, shedding new light on enhancement of thermal conductivity of polymer composites.