Carbon hybrid fillers composed of carbon nanotubes directly grown on graphene nanoplatelets for effective thermal conductivity in epoxy composites

Abstract

Carbon nanomaterials are generally used to promote the thermal conductivity of polymer composites. However, individual graphene nanoplatelets (GNPs) or carbon nanotubes (CNTs) limit the realization of the desirable thermal conductivity of the composite in both through- and in-plane directions. In this work, we present the thermal conductivity enhancement of the epoxy composite with carbon hybrid fillers composed of CNTs directly grown on the GNP support. The composite with 20 wt% hybrid filler loading showed 300% and 50% through-plane thermal conductivity improvements in comparison with the individual CNTs and GNPs, respectively. Moreover, it showed an enhanced thermal conductivity of up to 12% higher than that of the simply mixed GNP and CNT fillers. In more detail, hybrid fillers, whose CNTs were synthesized on the GNP support (Support C, Fe/Mo-MgO:GNP=1:0.456) for 60 min via chemical vapor deposition process, presented the highest through-plane thermal conductivity of 2.41 W m K in an epoxy composite.

Structure factors of carbon nanotubes on the thermal conductivity of carbon nanotube/epoxy composites

“…As I mentioned in our previous work, 19 the Rss' of the SWCNT/epoxy composite in the model is calculated to be 1.11×10 8 -2.11×10 8 m 2 K/W according to formula (7) in that paper. The Rss has been reported in literatures of Maruyama et al 38 (6 40 also proves that the interfacial thermal resistance between CNTs has negligible effects on the thermal conductivity of composites up to 10 wt%. Second, the contact area between SWCNTs in composites with agglomerated SWCNTs at a small loading is only a very small percentage of the contact area between SWCNT and matrix.…”

“…1 To make the best of the high thermal conductivity (more than 3000 W/mK) 2,3 of CNTs, the effects of some structure factors of CNTs such as the dispersion, morphology and size on the properties of CNT/epoxy composites have become a hot topic. [4][5][6][7][8][9][10][35][36][37] Yang 11 explored the effect of the dispersion of CNTs on the thermal conductivity of carbon nanotube/epoxy composites (kc) by functionalizing CNTs. The result shows that the k c of the sample containing functionalized CNTs can be enhanced by 67%-103% at a loading of 1 vol % -5 vol % compared with the k c of the sample containing pristine CNTs because of the good dispersion and the lower C sm (interfacial thermal conductance between the CNTs and epoxy matrix).…”

Fabrication of three dimensional carbon nanotube foam by direct conversion carbon dioxide and its application in supercapacitor

“…As shown in Fig. 2(b), the CNTF remained at 6.28% of the mass after the TGA test, which is attributed to Mg, MgO, Ni impurities and residual carbon [23]. For Ni(OH) 2 /CNTF composite the weight loss (2.93%) below 215 C is assigned to the removal of the adsorbed water and the evaporation of the intercalated water molecules.…”

Tailoring the interface in graphene/thermoset polymer composites: A critical review

“…[46][47][48][49][50][51][52] GO has been functionalized with molecules and macromolecules covalently or non-covalently depending on the application. Covalent functionalization involves formation of a strong chemical bond between graphene and polymer, while non-covalent functionalization involves physical interaction and does not induce defects sites unlike covalent modification.…”