Effect of vacancy defects on the heat transfer coefficient of partially stacked graphene sheets

Wang, Binghe; Cao, Qun; Shao, Wei; Cui, Zheng

doi:10.1007/s10853-022-07128-5

Cited by 5 publications

(5 citation statements)

References 50 publications

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“…In addition, our previous studies have verified the effect of the system size on heat transfer. 44,45 The system size had little effect on the graphene−graphene ITR, and the ITR was linearly dependent on the overlapping area. Therefore, validation of the system dimensions is not performed here.…”

Section: Resultsmentioning

confidence: 99%

Interfacial Thermal Transport between Stacked Functionalized Graphene Nanoflakes

Zhang,

Shao,

Cao

et al. 2024

J. Phys. Chem. C

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Graphene functionalization has been widely used in improving the thermal transport of graphene/epoxy composites owing to its performance in enhancing thermal conductivity and facilitating the formation of graphene networks. However, the heat transfer law and mechanism between functionalized graphene remain unclear. In this paper, the effects of distribution, type, and coverage of functional groups on the graphene−graphene interfacial thermal resistance (ITR) are analyzed by nonequilibrium molecular dynamics simulations. The results demonstrate that the graphene−graphene ITR depends on the synthetic effect of the graphene−graphene interaction, graphene−functional group interaction, and interaction between functional groups. The heat transfer contributions of those three interactions vary with the relative positions between functional groups. Then, the potential distribution of graphene is evaluated to compare the effects of different types of functional groups. It indicates that the potential difference is mainly attributed to functional groups. Compared with methyl, amino, and fluorine groups, hydroxyl groups have the largest potential difference and interaction. As the coverage of functional groups increases, the ITR of methylated graphene, aminated graphene, and hydroxylated graphene decreases inversely, whereas that of fluorinated graphene increases first and then decreases inversely. This work provides practical importance for the design and application of functionalized graphene in composite materials.

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Section: Resultsmentioning

confidence: 99%

Interfacial Thermal Transport between Stacked Functionalized Graphene Nanoflakes

Zhang,

Shao,

Cao

et al. 2024

J. Phys. Chem. C

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“…The TC of epoxy is 0.198 ± 0.082 W m –1 K –1 . The results agree well with the literature. − In addition, the size effect for partially stacked graphene has been presented in our previous work . Considering that the heat transfer of graphene/epoxy nanocomposites mainly depends on the graphene, as discussed later, the size effect for nanocomposites is not verified here.…”

Section: Resultsmentioning

confidence: 99%

“…Stacking is one of the connecting methods for constructing the graphene network. Previous work has shown that vacancy defects can enhance the heat transfer coefficient of the stacked graphene significantly. Here, to investigate the effect of the improved heat transfer of stacked graphene on the nanocomposites’ TC, carbon atoms in the stacking area of the stacked model are removed randomly to construct vacancy defects with a vacancy coverage rate of 4%.…”

Section: Resultsmentioning

confidence: 99%

“…It can be found that the nanocomposites’ TC increases first and then decreases as the vacancy coverage rate increases. This change is due to the synthetic effect of the interfacial thermal resistance and the in-plane thermal resistance . As the vacancy coverage rate increases, the interfacial thermal resistance in the stacking region decreases, but the in-plane thermal resistance of each graphene increases, which means the heat transfer of the GEIS model mainly depends on the heat transfer of the stacking region.…”

Section: Resultsmentioning

confidence: 99%

“…This change is due to the synthetic effect of the interfacial thermal resistance and the inplane thermal resistance. 50 As the vacancy coverage rate increases, the interfacial thermal resistance in the stacking region decreases, but the in-plane thermal resistance of each graphene increases, which means the heat transfer of the GEIS model mainly depends on the heat transfer of the stacking region. To understand the effect of vacancy defects on the TC of the GEIS model, the GEIS model with 2% vacancy defects, which has the largest TC (1.512 W m −1 K −1 ) in the simulation results, is adopted to study the heat-transfer process further.…”

Section: Heat Transfer Enhancement Of Graphene/epoxymentioning

confidence: 99%

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Thermal Conductivity Enhancement of Graphene/Epoxy Nanocomposites by Reducing Interfacial Thermal Resistance

et al. 2023

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The application of graphene/epoxy composites in microelectronic devices has been greatly limited by interfacial thermal resistance (ITR), which has been widely studied to improve the composites’ thermal conductivity. However, the effect of changing ITR on the thermal conductivity of nanocomposites at the nanoscale remains unclear. Here, several common methods are used to decrease graphene–epoxy ITR and graphene–graphene ITR, and the enhanced degree of nanocomposites’ thermal conductivity is investigated by molecular dynamics. First, the graphene concentration is proven to influence thermal conductivity slightly. Then, nanocomposites are simplified as three representative volume element models: the non-contacted model, the stacked model, and the intersected model. For the non-contacted model, the graphene–epoxy interfacial heat transfer coefficient is increased by 303% by functionalizing the graphene edge with amino groups, and the thermal conductivity is improved by 45.3%. For the stacked model, the graphene–graphene ITR is decreased by 220% when vacancy defects are constructed in the stacking region, and the thermal conductivity is improved by 130%. The intersected model’s heat transfer coefficient in the intersecting node is increased by 590% by connecting two graphene sheets by covalent interactions, and the thermal conductivity is improved by 590%. Finally, the stacked and intersected models are combined to construct the graphene/epoxy nanocomposites with a graphene network, and the thermal conductivity can be adjusted by changing the vacancy coverage rate.

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The helium-vacancy complexes and helium bubbles formation mechanism in chromium: a comprehensive first-principle study

Jia,

Li,

Zhang

et al. 2023

J Mater Sci

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Effect of vacancy defects on the heat transfer coefficient of partially stacked graphene sheets

Cited by 5 publications

References 50 publications

Interfacial Thermal Transport between Stacked Functionalized Graphene Nanoflakes

Interfacial Thermal Transport between Stacked Functionalized Graphene Nanoflakes

Thermal Conductivity Enhancement of Graphene/Epoxy Nanocomposites by Reducing Interfacial Thermal Resistance

The helium-vacancy complexes and helium bubbles formation mechanism in chromium: a comprehensive first-principle study

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