Synergetic effects of graphene platelets and carbon nanotubes on the mechanical and thermal properties of epoxy composites

A remarkable synergetic effect between the multi-graphene platelets (MGPs) and multi-walled carbon nanotubes (MWCNTs) in improving the mechanical properties and thermal conductivity of epoxy composites is demonstrated. Stacking of individual two-dimensional MGPs is effectively inhibited by introducing one-dimensional MWCNTs. Long and tortuous MWCNTs can bridge adjacent MGPs and inhibit their aggregation, resulting in a high contact area between the MGP/MWCNT structures and the polymer matrix. Scanning electron microscope images of the fracture surfaces of the epoxy matrix showed that MWCNT/MGP hybrid nanofillers exhibited higher solubility and better compatibility than individual MWCNTs and MGPs did. The tensile strength of GD400-MWCNT/MGP/epoxy composites was 35.4% higher than that of the epoxy alone, compared to only a 0.9% increase in tensile strength for MGP/epoxy composites over the epoxy compound. Thermal conductivity increased by 146.9% using GD400-MWCNT/MGP hybrid fillers and 23.9% for MGP fillers, compared to non-derivatised epoxy.

Flexible MWCNTs can construct MGPs to form 3-D hybrid structure which inhibit face to face aggregation of multi-graphene platelets and MWCNTs can act as extended coordinating arms for the 3-D hybrid architectures, these arms entangle with polymer chain to provide stronger interaction between MWCNTs/MGPs and the epoxy matrix. A remarkable synergetic effect between the MGPs and MWCNTs on the enhanced mechanical properties and thermal conductivity of these epoxy composites was demonstrated.Figure optionsDownload as PowerPoint slideResearch highlights
► Tortuous MWCNTs construct MGPs to form 3-D hybrid structure and inhibit aggregation.
► MWCNTs act as extended coordinating arms for the hybrid architectures in composites.
► 3-D hybrid architectures exhibit a synergetic effect on performance of composites.