High thermal conductive poly(vinylidene fluoride)-based composites with well-dispersed carbon nanotubes/graphene three-dimensional network structure via reduced interfacial thermal resistance

摘要

Polymeric materials exhibit superior advantages, while the low thermal conductivity greatly limited their applications in heat exchangers. In this study, a high thermal conductive poly(vinylidene fluoride) (PVDF) composite was prepared through constructing a three-dimensional network conductive structure with modified multi-wall carbon nanotubes (s-MWCNTs) and graphene (GE) in PVDF matrix. The thermal conductivity was enhanced by 711.1% in s-MWCNTs/GE/PVDF composite compared to that of PVDF. The results revealed that s-MWCNTs could not only effectively inhibit the stacking between GE lamellars and promote the formation of a well-dispersed three-dimensional s-MWCNTs/GE network structure, but also largely increase the interfacial compatibility between hybrid fillers and matrix. Above results were verified via a classic Effective Medium Theory model, confirming the significantly improved dispersibility and greatly reduced interfacial thermal resistance of composites. The formation of denser network structure for heat conduction was demonstrated and the mechanism for enhanced thermal conductivity was then presented. This work highlights an effective strategy to achieve excellent thermal conductive polymeric materials, which may eliminate the barriers for polymeric materials in applying in heat exchange fields.