Tailoring Highly Ordered Graphene Framework in Epoxy for High-Performance Polymer-Based Heat Dissipation Plates

Abstract

As the power density and integration level of electronic devices increase, there are growing demands to improve the thermal conductivity of polymers for addressing the thermal management issues. On the basis of the ultrahigh intrinsic thermal conductivity, graphene has exhibited great potential as reinforcing fillers to develop polymer composites, but the resultant thermal conductivity of reported graphenebased composites is still limited. Here, an interconnected and highly ordered graphene framework (HOGF) composed of high-quality and horizontally aligned graphene sheets was developed by a porous film-templated assembly strategy, followed by a stress-induced orientation process and graphitization post-treatment. After embedding into the epoxy (EP), the HOGF/EP composite (24.7 vol %) exhibits a record-high in-plane thermal conductivity of 117 W m −1 K −1 , equivalent to ≈616 times higher than that of neat epoxy. This thermal conductivity enhancement is mainly because the HOGF as a filler concurrently has high intrinsic thermal conductivity, relatively high density, and a highly ordered structure, constructing superefficient phonon transport paths in the epoxy matrix. Additionally, the use of our HOGF/EP as a heat dissipation plate was demonstrated, and it achieved 75% enhancement in practical thermal management performance compared to that of conventional alumina for cooling the high-power LED.

High Thermal Conductivity 2D Materials: From Theory and Engineering to Applications

“…constructed a highly orientated graphene (HOG)&porous polyurethane (PU) composite film using the “digging and drying” method followed by a high pressure and temperature process. [ 188 ] The 24.7 vol% HOG&PU composite film reached an in‐plane κ value of 117 W m –1 K –1 , which was ≈616 times higher than that of intrinsic PU. They also demonstrated an HOG&PU film as a heat‐dissipation plate, showing a 75% enhancement compared to conventional Al.…”

Interconnected MXene/Graphene Network Constructed by Soft Template for Multi-Performance Improvement of Polymer Composites

“…Polymer sponges are a kind of continuous natural three-dimensional (3D) soft templates, which can effectively form continuous filler interconnected networks through simple dipping or coating [ 7 – 9 ]. Long-range continuous electrical [ 10 – 12 ] and thermal network [ 13 – 15 ] is an essential structural feature for the formation of multifunctional polymer composites with high performance. The 3D soft templates represented by polyurethane (PU) sponge [ 11 , 16 – 19 ], melamine foam [ 10 , 20 – 22 ], and polyimide foam [ 23 , 24 ], combined with functional fillers, can easily obtain the continuous interconnected structure.…”

A highly orientational architecture formed by covalently bonded graphene to achieve high through-plane thermal conductivity of polymer composites

“…[3][4][5][6] Polymer materials present comprehensive properties, such as great mechanical strength, high chemical stability, and relatively light weight, but show extremely low thermal conductivities of 0.1-0.5 W m −1 K −1 due to the amorphous arrangement of molecular chains, which seriously restricts their cooling efficiency. 7 Introducing highly thermally conductive fillers into polymer matrices is an efficient way to address this issue, [8][9][10][11][12][13] in which graphene has attracted a great deal of attention due to its ultrahigh intrinsic thermal conductivity of up to ∼5000 W m −1 K −1 along the basal plane. 14 Consequently, a series of graphene-enhanced polymer composites have been developed via direct solution or melt blending processes.…”

“…20,21 Nowadays, it has become common to further improve the reinforcing effect of graphene via the rational design of microstructures within filler frameworks to ensure the consistency of the preferred direction for heat conduction between the composites and 2D fillers. 12,22,23 Therefore, certain technologies have been proposed to fabricate 3D graphene architectures with high orientations based on the interconnection of exfoliated graphene, typically including the ice-template method and nematic liquid crystal self-assembly. [24][25][26][27] Li et al fabricated a graphene architecture with a highly vertical orientation by a directional freezing method, and the obtained graphene-based epoxy composite exhibited a thermal conductivity of 2.69 W m −1 K −1 towards the through-plane direction with an ultralow filler content of ∼1.55 wt%, showing a thermal conductivity enhancement (TCE) per 1 wt% graphene loading of ∼690.…”