Thermal transmittance in graphene based networks for polymer matrix composites

Abstract

Graphene nanoribbons (GNRs) can be added as llers in polymer matrix composites for enhancing their thermo-mechanical properties. In the present study, we focus on the eect of chemical and geometrical characteristics of GNRs on the thermal conduction properties of composite materials. Congurations consisting of single and triple GNRs are here considered as representative building blocks of larger ller networks. In particular, GNRs with dierent length, relative orientation and number of cross-linkers are investigated. Based on results obtained by Reverse Non-equilibrium Molecular Dynamics simulations, we report correlations relating thermal conductivity and thermal boundary resistance of GNRs with their geometrical and chemical characteristics. These eects in turn aect the overall thermal transmittance of graphene based networks. In the broader context of eective medium theory, such results could be benecial to predict the thermal transport properties of devices made of polymer matrix composites, which currently nd application in energy, automotive, aerospace, electronics, sporting goods, and infrastructure industries.

Aromatic molecular junctions between graphene sheets: a molecular dynamics screening for enhanced thermal conductance

“…Later, Shen and coworkers 35 investigated the ITC in epoxy resin/graphene nanocomposites, as a function of the chemical functionalization of graphene, and showed that the highest ITC reduction occurs with triethylenetetramine moieties, because of their ability to penetrate in the epoxy resin and form covalent bonds. On the other hand, the thermal conductance associated with filler-filler contacts, in this work referred to as Thermal Boundary Conductance (TBC), was also studied numerically by various authors, specifically between carbon nanotubes and graphene platelets surface-functionalized with small bridging groups such as oxygen or methylene bridges [36][37][38][39] , short alkyl chains 40 or benzene 41 . TBC of alkyl molecular junctions covalently bound between two graphene flakes was investigated in details by Li and coworkers 40 Recently, we also reported NEMD simulations of edge-to-edge alkyl junctions between graphene nanoribbons 42 , where covalent bonding was compared to Van der Waals forces between interpenetrating molecules.…”

Heat Transfer at the Interface of Graphene Nanoribbons with Different Relative Orientations and Gaps

“…The considerable impact of R k on the effective λ of PNCs has stimulated the investigation of new approaches to reducing thermal resistances at interfaces. For example, the presence of edge-grafted molecular junctions or cross-linkers between graphene nanofillers was experimentally and numerically found to reduce the thermal resistance at the filler-filler interface [35,36]. Furthermore, the controlled chemical functionalization of carbon nanofillers improved the thermal transport across filler-matrix interfaces [37][38][39][40], while reducing the thermal conductivity of the nanofillers at the same time [41].…”

Sliding Dynamics of Parallel Graphene Sheets: Effect of Geometry and Van Der Waals Interactions on Nano-Spring Behavior

“…Carbon nanotubes (CNTs) and graphene are promising building blocks for nanoelectromechanical systems (NEMS)-such as nanomotors [1,2], nanoprobes [3,4], nanoresistors [5], or nanoswitches [6]due to their outstanding mechanical [7], electronic [8], and thermal [9][10][11] properties. In particular, both the telescoping motion between concentric CNTs and multiple layers of graphene (graphite) have shown remarkable ultra-low friction, with almost no hysteresis or dissipation [12][13][14].…”