Covalently interconnected carbon nanotubes network enhancing thermal conductivity of EP-based composite

The miniaturization of integrated circuits promotes the rapid rise of polymer-based carbon nanotubes (CNTs) thermal conductive composites. However, the unordered arrangement structure and interfacial thermal resistance of CNTs become important obstacles affecting their application. The directional orientation driven of CNTs by external force and the bridge between CNTs constructed via covalent bonding could solve these issues. Herein, the freeze-casting orientation configuration and new CNTs grew in situ by ZIF-67 constructed the hierarchical structure of CNTs in epoxy resin (EP)-based composites. The composites with directional networks of interlinked CNTs achieve an out-plane thermal conductivity value (kappa(perpendicular to)) of 0.98 W m(-1) K-1 at filler loading of 5.8 vol%, which is 4.85 times high than that of pure EP. More importantly, non-equilibrium molecular dynamics (NEMD) simulations validated the advantage of using covalent bonding to connect CNTs. This work provides a way for the reasonable design of polymer-based CNTs thermal conductive composites.

Automated summary

The miniaturization of integrated circuits has led to the rapid development of thermal conductive composites based on polymer carbon nanotubes (CNTs). However, the disordered arrangement structure and interfacial thermal resistance of CNTs pose significant challenges to their application. This study proposes a solution through freeze-casting orientation configuration and the growth of new CNTs in situ, creating a hierarchical structure in epoxy resin (EP)-based composites. The resulting composites exhibit directional networks of interlinked CNTs and significantly enhanced thermal conductivity compared to pure EP. Non-equilibrium molecular dynamics (NEMD) simulations further support the advantage of using covalent bonding to connect CNTs. These findings contribute to the rational design of polymer-based CNT thermal conductive composites.