High In-plane Thermal Conductivity Research Articles

Anomalous size effects of ultra-small graphene sheets on the thermal properties of macroscopic films

Graphene films assembled from graphene nanosheets have achieved a wide range of applications in thermal management due to their ultra-high thermal conductivity. Although it is well established in the micron range that increasing the lateral size of graphene sheets enhances the thermal conductivity of graphene films. However, the preparation of large-size graphene sheets and their assembly into ordered film structures remain challenging, which impedes the development of high-performance thermally conductive graphene films. Herein, by unifying the properties of graphene sheets and preparation processes, we correlate the thermal conductivity of graphene films and the lateral size of starting sheets ranging from 0.32 to 20.32 μm and probe the underlying mechanism from the perspectives of macroscopic and microscopic structural defects. Surprisingly, decreasing lateral size to 0.32 μm achieved as high in-plane thermal conductivity (K//, 1550.06 ± 12.99 W/mK) and significantly higher through-plane thermal conductivity (K⊥, 8.11 ± 0.08 W/mK) of graphene films as the case of 20.32 μm. Besides, the commonly overlooked size effect of K⊥ shows an unexpected negative correlation, and the size effect of K// is also not monotonically increasing. These phenomena are correlated with micro-structure defects and lattice defects. Mechanism analysis reveals that thermally induced gas generation and the complex gas-sheet interactions during micro-structure evolution play a critical role in the size effect and may explain the unexpected negative size effect in the sub-micro range. These findings in size effects provide theoretical guidance for the selection of raw materials in fabricating highly thermally conductive graphene films.

Flexible yet impermeable composites with wrinkle structured BNNSs assembling for high-performance thermal management

Efficient thermal management has become one of the most critical issues of electronics because of the high heat flux generated from highly integrated, miniaturized, and increased power. Here we report highly flexible composites with aligned and overlapping interconnected boron nitride nanosheets (BNNSs) assembled in wrinkle structures. Besides high in-plane thermal conductivity of more than 26.58 W m−1 K−1, such structure rendered enhanced through-plane conduction along with increasing pre-stain. As thermal interface materials (TIMs) of both rigid and flexible devices, the composites revealed an outstanding thermal cooling capability outperforming some commercial TIMs. During a record-long bending process of more than 3000 cycles, the maximum temperature fluctuation of the flexible device with 100%-prestrained composite was only within 0.9 °C, less than one-third of that with commercial thermal pad. Moreover, the composite revealed a superior impermeability for flexible seals. Our results illustrate that the composites could be an ideal candidate for the thermal management of emerging flexible electronics.

Enhancing thermal conductivity and electromagnetic shielding performance of Ni-CNT/Al2O3/PVDF composite film with a multi-layered structure

To develop thermal interface materials with both high thermal conductivity and electromagnetic interference shielding, the polyvinylidene fluoride (PVDF) composite film was prepared by electrospinning and hot-pressing, using strategies of multi-layered structure and two fillers synergy of nickel modified carbon nanotube (Ni-CNT) and Al2O3 microspheres. The composite film consisted of a Ni-CNT filled PVDF electrospun fiber film as the top and bottom surface layers, and a PVDF electrospun fiber film electrostatically adsorbing Al2O3 microspheres and surface-sprayed with Ni-CNT as the middle layer. At a 20 wt% Ni-CNT in the surface layers and a 16.7 wt% Al2O3 and 5 wt% Ni-CNT in the middle layer, the composite film with a thickness of 0.1 mm exhibited optimal performances with electromagnetic wave shielding efficiency of 65 dB in the frequency range of 8.2–12.4 GHz, with 86% of the electromagnetic waves being absorbed. At the same time, the composite film had a high in-plane thermal conductivity of 4.02 W m−1 K−1, while maintaining a tensile strength of 25 MPa and flexibility.

Polyimide-assisted fabrication of highly oriented graphene-based all-carbon foams for increasing the thermal conductivity of polymer composites

Graphene and its derivatives are often preferentially oriented horizontally during processing because of their two-dimensional (2D) layer structure. As a result, thermal interface materials (TIMs) composed of a polymer matrix and graphene-derived fillers often have a high in-plane (IP) thermal conductivity (K), however, the low through-plane (TP) K makes them unsuitable for practical use. We report the development of high-quality polyimide/graphite nanosheets (PG) perpendicular to the plane using a directional freezing technique that increase the TP K of polymer-based composites. Graphene-derived nanosheets (GNs) were obtained by the crushing of scraps of highly thermally conductive graphene films. A water-soluble polyamic acid salt solution was used to disperse the hydrophobic GNs filler to achieve directional freezing. The polyimide, which facilitated the directional alignment of the GNs, was then graphitized. The introduction of the GNs increases the order and density of the PG, thus improving the strength and heat transfer performance of its polydimethylsiloxane (PDMS) composite. The obtained PG/PDMS composite (21.1% PG, mass fraction) has an impressive TP K of 14.56 W·m−1·K−1, 81 times that of pure PDMS. This simple polyimide-assisted 2D hydrophobic fillers alignment method provides ideas for the widespread fabrication of anisotropic TIMs and enables the reuse of scraps of graphene films.

High thermal conductivity and low dielectric polyimide nanocomposites using diamine-assisted mechanochemical exfoliation boron nitride and in-situ polymerization under pressure

Advanced integrated circuit materials demand polymer composites with exceptional thermal conductivity and low dielectric constant to minimize power consumption and improve signal transmission. However, conventional methods of improving the thermal conductivity of composites by incorporating thermal conductive fillers result in an increase in dielectric constant, producing a huge challenge in simultaneously achieving enhanced thermal conductivity and low dielectric constant. Herein, a brick-and-mortar structure has been successfully constructed through in-situ polymerization of the diamine-assisted mechanochemical exfoliated (DAME) boron nitride (BN) with trifluoromethyl-containing PI and microporous polyhedral oligomeric silsesquioxane (POSS) under pressure. The DAME functionalized BNNS (f-BN) exhibit high aspect ratios, few lattice defects, high yields and excellent dispersion in the POSS/PI matrix. Notably, the obtained 40 wt% f-BN/POSS/PI nanocomposite exhibits a high in-plane thermal conductivity of 17.76 W m−1 K−1 with a 488% enhancement compared to 40 wt% hBN/POSS/PI, and simultaneously maintains low dielectric constant of 2.76 and low dielectric loss of 0.0042 at 1 MHz close to the pure POSS/PI matrix. Density functional theory is utilized to reveal the possible chemical reactions between f-BN and diamine, and the impacts of interfacial functionalization on the thermal conductivity and dielectric properties of nanocomposites are illustrated by molecular dynamics simulations. Furthermore, the DAME method demonstrates good universality among polyimide matrices, and shows excellent practical implementation as a thermal interface material and flexible printed circuit board. This material provides a promising solution for integrated circuits by successfully addressing the challenge of combining low dielectric constant and high thermal conductivity in microelectronic systems.

Effect of Anisotropy of Reduced Graphene Oxide on Thermal and Electrical Properties in Silicon Carbide Matrix Composites.

Reduced graphene oxide, due to its structure, exhibits anisotropic properties, which are particularly evident in electrical and thermal conductivity. This study focuses on examining the influence of reduced graphene oxide in silicon carbide on these properties in directions perpendicular and parallel to the direction of the aligned rGO flakes in produced composites. Reduced graphene oxide is characterized by very high in-plane thermal and electrical conductivity. It was observed that the addition of rGO increases thermal conductivity from 64 W/mK (reference sample) up to 98 W/mK for a SiC-3 wt.% rGO composite in the direction parallel to the rGO flakes. In the perpendicular direction, the values were slightly lower, reaching up to 84 W/mK. The difference observed in electrical conductivity values is more significant and is 1-2 orders of magnitude higher for the flakes' alignment direction. The measured electrical conductivity increased from 1.2710-8 S/m for the reference SiC sinter up to 1.55 × 10-5 S/m and 1.2410-4 S/m for the composites with 3 wt.% rGO for the perpendicular and parallel directions, respectively. This represents an enhancement of four orders of magnitude, with a clearly visible influence of the anisotropy of the rGO. The composite's enhanced electrical and thermal conductivity make it particularly attractive for electronic devices and high-power applications.

Molecular simulation and experimental investigation of thermal conductivity of flexible graphite film

Flexible graphite film (FGF), as a traditional interface heat dissipation material, has high anisotropy. It is a challenge to enhance both in-plane and through-plane thermal conductivity of FGF. For this reason, the effects of oxygen content, layer spacing, density and particle size on the in-plane and through-plane thermal conductivity of FGF were studied by both molecular simulation and experimental investigation. The simulation results indicate that the ways to improve the thermal conductivity of FGF include reducing oxygen content and layer spacing, increasing the density and matching the size of graphite sheets. The FGF prepared from room temperature exfoliated graphite (RTFGF) has a wide range of adjustable density (1.3–2.0 g/cm3) and thickness (50–400 μm). The thermal conductivity of the RTFGF is significantly improved after heat treatment owing to reduced oxygen content and layer spacing, which is consistent with the simulation results. Moreover, RTFGF with both high in-plane (518 W⋅m−1⋅K−1) and through-plane (7.2 W⋅m−1⋅K−1) thermal conductivity can be obtained by particle size matching of graphite.

Graphenization of graphene oxide films for strongly anisotropic thermal conduction and high electromagnetic interference shielding

A macroscopic carbon film that has a “graphenic” structure (defect-free in-plane graphene lattice yet absence of Bernal type graphitic stacking order), may inherit the exotic properties of rotated/slipped few-layer graphene (e.g., high flexibility and anisotropic transport properties). However, the fabrication of such a film remains challenging and unreported. Here we show that the annealing of reduced electrochemical graphene oxide (REGO), which has fewer in-plane defects than the conventional graphene oxide from Hummers’ method, leads to a nearly intact graphene lattice (Raman ID/IG down to 0.03) without restoring the graphitic stacking order (I2D/IG > 1 and a single Lorentzian 2D peak). Atomic resolution transmission electron microscopy verifies the unique graphenic structure with random interlayer rotations. Density functional theory calculations imply the low defect density of REGO can suppress the interplanar interaction between undercoordinated carbon atoms, therefore inhibiting cross-plane migration of vacancies and the consequent establishment of stacking order. The annealed, graphenic REGO film is highly flexible and has an in-plane to cross-plane thermal conductivity ratio of 835 (among the highest reported for anisotropic thermal conductors). This high anisotropic ratio is attributed to the inhibited through-plane heat transport (0.26 W m−1 K−1) by the interlayer rotations and the high in-plane thermal conductivity (218 W m−1 K−1) enabled by intact graphene lattice. The graphenic films show high electromagnetic interference shielding effectiveness of 80.3 dB at a thickness of 53 μm and 42.4 dB at 5.7 μm, with an absolute effectiveness (>70000 dB cm2 g−1) superior to two-dimensional metal carbides (MXenes) and Al foil.

Internal oriented strategy of the hBN composite resin with enhanced in-plane or through-plane thermal conductivity via 3D printing

In this work, we report a facile preparation of the composite resin with significantly enhanced high in-plane or through-plane thermal conductivity via controlling the layer thickness of digital light processing (DLP) 3D printing less than the lateral size of hBN. The thermal conductivity of the composite resin reaches up to 7.962 W∙m−1∙K−1 along the oriented direction at the content of 30 wt% hBN flakes with a lateral size of 25 μm under the 3D printing layer thickness of 15 μm, which is about 44 times greater than that of the pure resin. It is found that a lower thickness of the printing layer leads to a higher degree of the hBN flake orientation and higher thermal conductivity of the composite resin. Inspired by this method, the thermal conductivity prediction model based on the process parameters is established and has a higher accuracy than the traditional model. In addition, the 3D printed composite resin exhibits excellent thermostability, low water absorption and volume shrinkage, favorable mechanical properties, and great dielectric properties. This approach provides a new vision for the application of 3D printing in thermal management.

Twist-Dependent Anisotropic Thermal Conductivity in Homogeneous MoS2 Stacks

Thermal transport property of homogeneous twisted molybdenum disulfide (MoS2) is investigated using non-equilibrium molecular dynamics simulations with the state-of-art force fields. The simulation results demonstrate that the cross-plane thermal conductivity strongly depends on the interfacial twist angle, while it has only a minor effect on the in-plane thermal conductivity, exhibiting a highly anisotropic nature. A frequency-decomposed phonon analysis showed that the cross-plane and in-plane thermal conductivity of MoS2 are dominated by the phonons with frequencies below 12.5 THz and 7.5 THz, respectively. As the interfacial twist angle increases, these low-frequency phonons significantly attenuate the phonon transport across the interface, leading to impeded cross-plane thermal transport. However, the in-plane phonon transport is almost unaffected, which allows for maintaining high in-plane thermal conductivity. Furthermore, our study revealed a strong size dependence for both cross-plane and in-plane thermal conductivities due to the influence of low-frequency phonons in MoS2. The maximum thermal conductivity anisotropy ratio is estimated as ∼400 for twisted MoS2 from our simulation, which is in the same order of magnitude as recent experimental results (∼900). Our study highlights the potential of twist engineering as a tool for tailoring the thermal transport properties of layered materials.

Large-area, highly thermally conductive, but electrically insulative industrial aramid papers with hierarchical multiscale compositing structures

The rapid development of emerging 5G electrical fields has put forward high requirements to the thermal dissipation performance of industrial aramid papers (IAPs), which are commonly used as the insulation layers of electrical equipment. Herein, we reported a facile method for preparing large-area (> 7000 cm2), thermally conductive, but electrically insulative IAPs by compounding multiscale boron nitride nanosheets (BNNSs), industrial diamond microparticles (DMPs), and industrial aramid micropulps and microfibers (AMPs & AMFs) towards hierarchical compositing structures. Specifically, BNNSs can adhere to the surface of DMPs through electrostatic interaction and reduce the thermal resistance between neighboring DMPs, which ultimately ensures high in-plane thermal conductivity (11.66 W/(mK)) of IAPs, which is about 7 times that of pure aramid papers. Meanwhile, IAPs also exhibit high volume resistivity of 4.95×1015 Ω·cm. At last, the IAPs were successfully applied in a transformer for insulation and thermal conducting, demonstrating their high potential in industrial electrical equipment.

Ultrahigh in-plane thermal conductive epoxy composites by cellulose-supported GnPs@PDA skeleton under stress-induced orientation strategy

Designing anisotropic thermally conductive networks in thermal management materials can effectively exploit the high in-plane thermal conductivity of two-dimensional fillers to achieve high heat transfer efficiency along the predetermined direction, which is the hotspot for thermal management materials. However, constructing such an interconnected network with an orderly alignment structure through thermally conductive fillers has proved challenging. In this study, a high-density cellulose-supported GnPs@PDA skeleton with an interconnected and ordered structure was successfully prepared through the stress-induced strategy. After embedding into the epoxy resin, the EP/CGP composites with 22.1 vol% filler content exhibit an excellent in-plane thermal conductivity of 8.39 W/mK under a 75 % compression ratio, which is 12.3 times higher than that without compression. The enhancement of thermal conductivity for EP/CGP composites under the stress-induced orientation strategy is illustrated by the finite element analysis and metal foam theory. Furthermore, the transient heat transmission processes of the composites are recorded to verify their prospect in thermal management applications. This novel approach sheds light on the fabrication of thermally conductive networks with interconnected and ordered structures for next-generation thermal management materials.

Hot-pressing induced alignment of AlN whiskers in polymer matrix leading to enhanced in-plane thermal conductivity

With the increased integration of electronic devices, the demands for polymer-based composites with higher thermal conductivity as thermal management materials are gradually growing. Compared with regular spherical morphology, 1D particles with high aspect ratio are regarded as ideal fillers for polymer matrix due to their favorable construction of thermally conductive channels. In this work, high-aspect-ratio AlN whiskers were successfully synthesized by a modified direct-nitriding method, which were further combined with ultra high molecular weight polyethylene (UHMWPE) to prepare the thermally conductive composites by a facile hot-pressing process. The introduction and alignment of AlN whiskers along horizontal direction resulted in a high in-plane thermal conductivity of 7.12 W/(m·K) at the 62.5 wt% filling fraction, which was 16 times than that of UHMWPE. In addition, due to the cross-linking of 1D AlN whiskers, the composites also exhibited high thermal stability and mechanical strength, making them very promising for application as high-performance thermal management materials.

Ultra-high thermal conductivity FGN/PVA/MXene composite films with good electrical insulation

The polyvinyl alcohol (PVA) -based composite films with the high thermal conductivity and excellent electrical insulation have attracted more and more attention due to their advantages such as light weight and easy processing. Herein, a series of three-component fluorographene nanosheets (FGN)/PVA/MXene(FPM) films were prepared by vacuum assisted filtration technology with the single layer FGN (1.5–2.5 μm) and PVA as main raw materials and a small amount of Ti3C2Tx MXene nanosheets (200–600 nm) as the third phase. The FPM films had ultra-high in-plane thermal conductivity of 122.5 W/(m·K) when the addition of Ti3C2Tx MXene was 0.8 wt% of the composite film. The reason is that the Ti3C2Tx MXene nanosheets replace the high thermal resistance PVA molecules and connect the adjacent FGN powders horizontally (via hydrogen bonding), thus greatly reducing phonon scattering at the gap. The FPM films achieve extremely high in-plane thermal conductivity while maintaining excellent insulation and can be used for heat dissipation of small electrical appliances (such as mobile phone CPU). Meanwhile, it provides a new idea for the preparation of composite films with the low cost and high thermal conductivity.

Enhanced In-Plane Thermal Conductivity and Mechanical Strength of Flexible Films by Aligning and Interconnecting Si3N4 Nanowires.

As the rapid development of advanced foldable electronic devices, flexible and insulating composite films with ultra-high in-plane thermal conductivity have received increasing attention as thermal management materials. Silicon nitride nanowires (Si3N4NWs) have been considered as promising fillers for preparing anisotropic thermally conductive composite films due to their extremely high thermal conductivity, low dielectric properties, and excellent mechanical properties. However, an efficient approach to synthesize Si3N4NWs in a large scale still need to be explored. In this work, large quantities of Si3N4NWs were successfully prepared using a modified CRN method, presenting the advantages of high aspect ratio, high purity, and easy collection. On the basis, the super-flexible PVA/Si3N4NWs composite films were further prepared with the assistance of vacuum filtration method. Due to the highly oriented Si3N4NWs interconnected to form a complete phonon transport network in the horizontal direction, the composite films exhibited a high in-plane thermal conductivity of 15.4 W·m-1·K-1. The enhancement effect of Si3N4NWs on the composite thermal conductivity was further demonstrated by the actual heat transfer process and finite element simulations. More significantly, the Si3N4NWs enabled the composite film presenting good thermal stability, high electrical insulation, and excellent mechanical strength, which was beneficial for thermal management applications in modern electronic devices.

A dual-domain 3 ω method for measuring the in-plane thermal conductivity of high-conductive thin films

The thermal conductivity measurement of films with submicrometer thicknesses is difficult due to their exceptionally low thermal resistance, which makes it challenging to accurately measure the temperature changes that occur as heat flows through the film. Thus, specialized and sensitive measurement techniques are required. 3ω method is a widely used and reliable tool for measuring the thermal conductivity of films. However, the high in-plane thermal conductivity in thin films results in rapid heat dissipation across the thin film, resulting in poor measurement sensitivity and making it difficult to accurately measure the temperature gradient with the traditional 3ω method. Also, the traditional 3ω method requires cross-plane thermal conductivity to derive the in-plane counterpart. Here, we introduce a dual-domain 3ω method that adopts AC-modulated heating and electrode arrays facilitating surface temperature profiling: (1) the sensitivity was significantly improved due to the employment of low-thermal-conductivity-substrate, and (2) cross-plane thermal conductivity is not required for the analysis of in-plane counterpart. This measurement platform allows us to control heat penetration in depth via varied heating frequencies as well as spatial temperature detection through laterally distributed electrodes on the thin film surface. By utilizing the described method, we have determined the in-plane thermal conductivity of a copper film, having a thickness of 300 nm, which was found to be 346 Wm−1K−1 and validated by the Wiedemann–Franz law.

Fabrication of ZnO@Fe2O3 superhydrophobic coatings with high thermal conductivity

Efficient thermal management materials are an integral part of electronic devices and can quickly contribute to their heat dissipation, thereby greatly improving their reliability, stability and service life. However, the inherent hygroscopicity of the film surface sets obstacles to the reliability and structural stability of electronic devices. To address these issues, a bionic structural design was obtained by spraying a polyurethane/stearic acid/zinc oxide‑iron oxide composite powder (TPU/STA/ZnO@Fe2O3) on the surface of graphene composite films. At the same time, the graphene composite film has a high in-plane thermal conductivity (up to 533 W−1·m−1·K−1) and is able to reduce the film surface temperature to room temperature within 5 s due to its highly ordered layered design and strong hydrogen bonding interactions. In addition, the composite film offers a range of advantages such as good hydrophobicity and electrical conductivity. With a water contact angle of up to 159.5 ± 2° and an electrical conductivity of up to 3 × 103 S/m in steady state, the results show that the superhydrophobic graphene composite film has good physical, chemical and mechanical stability, as well as self-cleaning capabilities. It also retains good flexibility and reliability under 350 bending cycles. In this regard, the development of graphene composite films with high thermal conductivity, high superhydrophobicity, good electrical conductivity and flexibility is expected to be used as thermally conductive materials, opening up a new path in the field of thermally conductive heat dissipation materials for electronic components.

Room-Temperature Self-Healing Soft Composite Network with Unprecedented Crack Propagation Resistance Enabled by Supramolecular Assembled Lamellar Structure.

Soft self-healing materials are compelling candidates for stretchable devices because of their excellent compliance, extensibility, and self-restorability. However, most existing soft self-healing polymers suffer from crack propagation and irreversible fatigue failure due to easy breakage of their dynamic amorphous low-energy polymer networks. Herein, inspired by distinct structure-property relationship of biological tissues, we propose a supramolecular interfacial assembly strategy of preparing soft self-healing composites with unprecedented crack propagation resistance by structurally engineering preferentially-aligned lamellar structures within dynamic and super-stretchable poly(urea-ureathane) matrixes (which can be elongated to 24750× its original length). Such a design affords world-record fracture energy (501.6kJ m-2 ), ultra-high fatigue threshold (4064.1 J m-2 ), and outstanding elastic restorability (dimensional recovery from 13 times elongation), and preserving low modulus (1.2MPa), high stretchability (3200%), high room-temperature self-healing efficiency (97%). Thereby, the resultant composite represents the best of its kind and even surpasses most natural biological tissues. The lamellar MXene (2D transition metal carbide/carbonitride) structure also leads to a relatively high in-plane thermal conductivity, enabling composite as stretchable thermo-conductive skins applied in joints of robotics to enable thermal dissipation. The present work illustrates a viable approach how autonomous self-healing, crack tolerance and fatigue resistance can be merged in future material design. This article is protected by copyright. All rights reserved.

Lightweight, electrical insulating, and high thermally conductive all-polymer composites with reinforced interfaces

High thermally conductive materials with good electrical insulating and mechanical properties are indispensable for electronics. Aiming for all-polymer composites with light weight, electrical insulation and high thermal conductivity (TC), ultrahigh molecular weight polyethylene (UHMWPE) fibers/epoxy composites with two kinds of fiber orientation structures (0°/90°, ±45°) were fabricated by hot-pressing. It is found that the in-plane TC of ±45° composite is approximately 1.3–1.4 times that of 0/90° one, and the corresponding mechanism is verified by finite element simulation and model calculation. Thermally conductive pathways formed by UHMWPE fibers endow 0/90° and ±45° composites with the in-plane TC of 9.94 and 13.61 Wm−1K−1, respectively. Through depositing polydopamine (PDA) and grafting polyether amine (PEA) onto the surface of fibers, the poor fiber/epoxy interface was improved, resulting in 40.7% and 52.3% improvement in interlaminar shear strength (ILSS) and shear modulus, respectively. Simultaneously, a higher in-plane TC as high as 15.76 Wm−1K−1 is achieved. The heat dissipation evaluation indicates that the composite can reduce the temperature of the resistance wire by 14 °C. This work reveals the great potential of UHMWPE fibers in heat dissipation and provides a strong candidate for electrical insulating support materials with high TC for heat management of electronics.

Anisotropic graphene films with improved thermal conductivity and flexibility for efficient thermal management

The rapid development of miniaturization and densification of electronic devices brings substantive needs for highly thermally conductive and flexible thermal interface materials (TIM) to ensure service reliability and prolong the lifetime of electronic components. Herein, we proposed highly thermally conductive and flexible graphene (Gr) films by a vacuum-assisted filtration strategy. Driven by the strong vacuum shear force and the dispersing effect of Polyvinyl pyrrolidone (PVP), the Gr sheets stacked layered-by-layered owing to hydrogen bond (H-bond). The highly laminated Gr/PVP films (GPVP-F) exhibited high in-plane thermal conductivity of 81.2 W m−1 K−1 and through-plane thermal conductivity of 5.1 W m−1 K−1. In actual applications, the GPVP-F cooled the light-emitting diode (LED) chip by 4.3 °C (from 46.1 °C to 41.8 °C) when being used as flexible TIM, which was at an advanced level for room-temperature device (＜ 50 °C) cooling. Besides, GPVP-F still performed excellent thermal conductivity (68.1 W m−1 K−1) even at 100 °C and splendid stability after 10 times of heating-cooling cycles. More importantly, the meritorious flexibility ensured GPVP-F being capable of applying in the device with irregular shapes. All the above results bring GPVP-F a promising prospect in thermal management of electronic devices.