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

Highly oriented BN-based TIMs with high through-plane thermal conductivity and low compression modulus

In the pursuit of effective thermal management for electronic devices, it is crucial to develop insulation thermal interface materials (TIMs) that exhibit exceptional through-plane thermal conductivity, low thermal resistance, and minimal compression modulus. Boron nitride (BN), given its outstanding thermal conduction and insulation properties, has garnered significant attention as a potential material for this purpose. However, previously reported BN-based composites have consistently demonstrated through-plane thermal conductivity below 10 W m-1 K-1 and high compression modulus, whilst also presenting challenges in terms of mass production. In this study, low molecular weight polydimethylsiloxane (PDMS) and large-size BN were utilized as the foundational materials. Utilizing a rolling-curing integrated apparatus, we successfully accomplished the continuous preparation of large-sized, high-adhesion BN films. Subsequent implementation of stacking, cold pressing, and vertical cutting techniques enabled the attainment of a remarkable BN-based TIM, characterized by an unprecedented through-plane thermal conductivity of up to 12.11 W m-1 K-1, remarkably low compression modulus (55 kPa), and total effective thermal resistance (0.16 °C in2 W-1, 50 Psi). During the TIMs performance evaluation, our TIMs demonstrated superior heat dissipation capabilities compared with commercial TIMs. At a heating power density of 40 W cm-2, the steady-state temperature of the ceramic heating element was found to be 7 °C lower than that of the commercial TIMs. This pioneering feat not only contributes valuable technical insights for the development of high-performance insulating TIMs but also establishes a solid foundation for widespread implementation in thermal management applications across a range of electronic devices.

SPI-Modified h-BN Nanosheets-Based Thermal Interface Materials for Thermal Management Applications

The rising concern over the usage of electronic devices and the operating environment requires efficient thermal interface materials (TIMs) to take away the excess heat generated from hotspots. TIMs are crucial in dissipating undesired heat by transferring energy from the source to the heat sink. Silicone oil (SO)-based composites are the most used TIMs due to their strong bonding and oxidation resistance. However, thermal grease performance is unreliable due to aging effects, toxic chemicals, and a higher percentage of fillers. In this work, TIMs are prepared using exfoliated hexagonal boron nitride nanosheets (h-BNNS) as a nanofiller, and they were functionalized by ecofriendly natural biopolymer soy protein isolate (SPI). The exfoliated h-BNNS has an average lateral size of ∼266 nm. The functionalized h-BNNS/SPI are used as fillers in the SO matrix, and composites are prepared using solution mixing. Hydrogen bonding is present between the organic chain/oxygen in silicone polymer, and the functionalized h-BNNS are evident from the FTIR measurements. The thermal conductivity of h-BNNS/SPI/SO was measured using the modified transient plane source (MTPS) method. At room temperature, the maximum thermal conductivity is 1.162 Wm-1K-1 (833% enhancement) at 50 wt % of 3:1 ratio of h-BNNS:SPI, and the thermal resistance (TR) of the composite is 5.249 × 106 K/W which is calculated using the Foygel nonlinear model. The heat management application was demonstrated by applying TIM on a 10 W LED bulb. It was found that during heating, the 50 wt % TIM decreases the surface temperature of LED by ∼6 °C compared with the pure SO-based TIM after 10 min of ON condition. During cooling, the modified TIM reduces the surface temperature by ∼8 °C under OFF conditions within 1 min. The results indicate that natural polymers can effectively stabilize and link layered materials, enhancing the efficiency of TIMs for cooling electronics and LEDs.

Enhanced reduction of graphene oxide via laser-dispersion coupling: Towards large-scale, low-defect graphene for crease-free heat-dissipating membranes in advanced flexible electronics

The advancement of flexible electronics demands improved components, necessitating heat dissipation membranes (HDMs) to exhibit high thermal conductivity while maintaining structural integrity and performance stability even after extensive deformation. Herein, we have devised a laser-modulated reduction technique for graphene oxide (GO), enabling the fabrication of high-quality, large-scale, low-defect graphene, which yields high-performance HDMs after orderly deposition. The work underscores the crucial role of the laser wavelength and dispersion liquid's coupling intensity in influencing the morphology and properties of graphene. Optimal coupling effect and energy conversion are realized when a laser of 1064 nm wavelength irradiates a triethylene glycol (TEG)/N,N-Dimethylformamide (DMF) dispersion. This unique synergy generates high transient energy, which facilitates the deprotonation process and ensures a swift, comprehensive GO reduction. In contrast to conventional water-based laser reduction methods, the accelerated reaction magnifies the size of the graphene sheets by mitigating the ablation effect. After membrane construction with an ordered structure, the corresponding membrane exhibits a high thermal conductivity of 1632 W m-1 K-1, requiring only ∼1/10 of the total preparation time required by other reported methods. Remarkably, the resulting HDM demonstrates superior resilience against creasing and folding, maintaining excellent smoothness and negligible reduction in thermal conductivity after violent rubbing. The combination of exceptional flexibility and thermal conductivity in HDMs paves the way for long-term practical use in the flexible electronics industry.

2D Materials-Based Thermal Interface Materials: Structure, Properties, and Applications

The challenges associated with heat dissipation in high-power electronic devices used in communication, new energy, and aerospace equipment have spurred an urgent need for high-performance thermal interface materials (TIMs) to establish efficient heat transfer pathways from the heater (chip) to heat sinks. Recently, emerging 2D materials, such as graphene and boron nitride, renowned for their ultrahigh basal-plane thermal conductivity and the capacity to facilitate cross-scale, multi-morphic structural design, have found widespread use as thermal fillers in the production of high-performance TIMs. To deepen the understanding of 2D material-based TIMs, this review focuses primarily on graphene and boron nitride-based TIMs, exploring their structures, properties, and applications. Building on this foundation, the developmental history of these TIMs is emphasized and a detailed analysis of critical challenges and potential solutions is provided. Additionally, the preparation and application of some other novel 2D materials-based TIMs are briefly introduced, aiming to offer constructive guidance for the future development of high-performance TIMs.

Application-Driven High-Thermal-Conductivity Polymer Nanocomposites

Polymer nanocomposites combine the merits of polymer matrices and the unusual effects of nanoscale reinforcements and have been recognized as important members of the material family. Being a fundamental material property, thermal conductivity directly affects the molding and processing of materials as well as the design and performance of devices and systems. Polymer nanocomposites have been used in numerous industrial fields; thus, high demands are placed on the thermal conductivity feature of polymer nanocomposites. In this Perspective, we first provide roadmaps for the development of polymer nanocomposites with isotropic, in-plane, and through-plane high thermal conductivities, demonstrating the great effect of nanoscale reinforcements on thermal conductivity enhancement of polymer nanocomposites. Then the significance of the thermal conductivity of polymer nanocomposites in different application fields, including wearable electronics, thermal interface materials, battery thermal management, dielectric capacitors, electrical equipment, solar thermal energy storage, biomedical applications, carbon dioxide capture, and radiative cooling, are highlighted. In future research, we should continue to focus on methods that can further improve the thermal conductivity of polymer nanocomposites. On the other hand, we should pay more attention to the synergistic improvement of the thermal conductivity and other properties of polymer nanocomposites. Emerging polymer nanocomposites with high thermal conductivity should be based on application-oriented research.

Patterned liquid metal embedded in brush-shaped polymers for dynamic thermal management

Interface thermal resistance has become a crucial barrier to effective thermal management in high-performance electronics and sensors. The growing complexity of operational conditions, such as irregular and dynamic surfaces, demands thermal interface materials (TIMs) to possess high thermal conductivity and soft elasticity. However, developing materials that simultaneously combine soft elasticity and high thermal conductivity remains a challenging task. Herein, we utilize a vertically oriented graphene aerogel (VGA) and rationally design liquid metal (LM) networks to achieve directional and adjustable pathways within the composite. Subsequently, we leverage the advantages of the low elastic modulus and high deformation capabilities of brush-shaped polydimethylsiloxane (BPDMS), together with the bicontinuous thermal conduction path constructed by VGA and LM networks. Ultimately, the designed composite of patterned liquid metal/vertically oriented graphene aerogel/brush-shaped PDMS (LM-VGA/BPDMS) shows a high thermal conductivity (7.11 W m-1 K-1), an ultra-low elastic modulus (10.13 kPa), excellent resilience, and a low interface thermal resistance (14.1 K mm2 W-1). This LM-VGA/BPDMS soft composite showcases a stable heat dissipation capability at dynamically changing interfaces, as well as excellent adaptability to different irregular surfaces. This strategy holds important application prospects in the fields of interface thermal management and thermal sensing in extremely complex environments.

High-Performance Graphene Biocomposite Enabled by Fe3+ Coordination for Thermal Management

Emerging biocomposites with excellent heat dissipation capabilities and inherent sustainability are urgently needed to address the cooling issues of modern electronics and growing environmental concerns. However, the moisture stability, mechanical performance, thermal conductivity, and even flame retardancy of biomass-based materials are generally insufficient for practical thermal management applications. Herein, we present a high-performance graphene biocomposite consisting of carboxylated cellulose nanofibers and graphene nanosheets through an evaporation-induced self-assembly and subsequent Fe3+ cross-linking strategy. The Fe3+ coordination plays a critical role in stabilizing the material structure, thereby improving the mechanical strength and water stability of the biocomposite films, and its effect is revealed by density functional theory calculations. The hierarchical structure of the biocomposite films also leads to a high in-plane thermal conductivity of 42.5 W m-1 K-1, enabling a superior heat transfer performance. Furthermore, the resultant biocomposite films exhibit outstanding Joule heating performance with a fast thermal response and long-term stability, improved thermal stability, and flame retardancy. Therefore, such a general strategy and the desired overall properties of the biocomposite films offer wide application prospects for functional and safe thermal management.

Advances in Biocarbon and Soft Material Assembly for Enthalpy Storage: Fundamentals, Mechanisms, and Multimodal Applications

High-value-added biomass materials like biocarbon are being actively pursued integrating them with soft materials in a broad range of advanced renewable energy technologies owing to their advantages, such as lightweight, relatively low-cost, diverse structural engineering applications, and high energy storage potential. Consequently, the hybrid integration of soft and biomass-derived materials shall store energy to mitigate intermittency issues, primarily through enthalpy storage during phase change. This paper introduces the recent advances in the development of natural biomaterial-derived carbon materials in soft material assembly and its applications in multidirectional renewable energy storage. Various emerging biocarbon materials (biochar, carbon fiber, graphene, nanoporous carbon nanosheets (2D), and carbon aerogel) with intrinsic structures and engineered designs for enhanced enthalpy storage and multimodal applications are discussed. The fundamental design approaches, working mechanisms, and feature applications, such as including thermal management and electromagnetic interference shielding, sensors, flexible electronics and transparent nanopaper, and environmental applications of biocarbon-based soft material composites are highlighted. Furthermore, the challenges and potential opportunities of biocarbon-based composites are identified, and prospects in biomaterial-based soft materials composites are presented.

Significantly Enhancing Mechanical and Thermal Properties of Cellulose-Based Composites by Adding Small Amounts of Lysozyme-Modified Graphene Nanoplatelets via Forming Strong Double-Cross-Linked Interface Interactions

Thermally conductive cellulose-based composites have great application potential in the thermal management of portable and wearable electronic devices. In this work, cellulose-based composites with excellent mechanical and thermal properties were developed by using lysozyme-modified graphene nanoplatelets (LmGNP), epichlorohydrin (ECH), and hydrolyzed cellulose via forming strong double-cross-linked interface interactions, including the hydrogen bond network generated between LmGNP and cellulose and the chemical cross-link of ECH. As for the composites containing 8 wt % LmGNP, the in-plane thermal conductivity was 3.341 W·m-1K-1, while the tensile stress was 114.60 MPa, which increased by 297.3 and 146.2%, respectively, compared to pure cellulose. Along with the good stability, insulation, and lightweight properties, the fabricated composites have the potential to become a promising heat dissipation material for wearable electronic devices.

Tetris-Style Stacking Process to Tailor the Orientation of Carbon Fiber Scaffolds for Efficient Heat Dissipation

As the miniaturization of electronic devices and complication of electronic packaging, there are growing demands for thermal interfacial materials with enhanced thermal conductivity and the capability to direct the heat toward heat sink for highly efficient heat dissipation. Pitch-based carbon fiber (CF) with ultrahigh axial thermal conductivity and aspect ratios exhibits great potential for developing thermally conductive composites as TIMs. However, it is still hard to fabricate composites with aligned carbon fiber in a general approach to fully utilize its excellent axial thermal conductivity in specific direction. Here, three types of CF scaffolds with different oriented structure were developed via magnetic field-assisted Tetris-style stacking and carbonization process. By regulating the magnetic field direction and initial stacking density, the self-supporting CF scaffolds with horizontally aligned (HCS), diagonally aligned and vertically aligned (VCS) fibers were constructed. After embedding the polydimethylsiloxane (PDMS), the three composites exhibited unique heat transfer properties, and the HCS/PDMS and VCS/PDMS composites presented a high thermal conductivity of 42.18 and 45.01 W m-1 K-1 in fiber alignment direction, respectively, which were about 209 and 224 times higher than that of PDMS. The excellent thermal conductivity is mainly ascribed that the oriented CF scaffolds construct effective phonon transport pathway in the matrix. In addition, fishbone-shaped CF scaffold was also produced by multiple stacking and carbonization process, and the prepared composites exhibited a controlled heat transfer path, which can allow more versatility in the design of thermal management system.

Nanopolyhybrids: Materials, Engineering Designs, and Advances in Thermal Management

The fundamental requirements for thermal comfort along with the unbalanced growth in the energy demand and consumption worldwide have triggered the development and innovation of advanced materials for high thermal-management capabilities. However, continuous development remains a significant challenge in designing thermally robust materials for the efficient thermal management of industrial devices and manufacturing technologies. The notable achievements thus far in nanopolyhybrid design technologies include multiresponsive energy harvesting/conversion (e.g., light, magnetic, and electric), thermoregulation (including microclimate), energy saving in construction, as well as the miniaturization, integration, and intelligentization of electronic systems. These are achieved by integrating nanomaterials and polymers with desired engineering strategies. Herein, fundamental design approaches that consider diverse nanomaterials and the properties of nanopolyhybrids are introduced, and the emerging applications of hybrid composites such as personal and electronic thermal management and advanced medical applications are highlighted. Finally, current challenges and outlook for future trends and prospects are summarized to develop nanopolyhybrid materials.

Reprocessable and Chemically Recyclable Hard Vitrimers Based on Liquid-Crystalline Epoxides

The rapid increase in demand for recyclable and reusable thermosets has necessitated the development of materials with chemical structures that exhibit these features. Thus, functional mesogenic epoxide monomers bearing both ester and imine groups that can be vitrimerized and recycled are reported herein. The compounds show mesophase characteristics at 100-200 °C and can be converted into hard epoxides by a common curing reaction. The obtained hard epoxides have high isotropic thermal conductivity (≈0.64 W m^-1 K^-1 ), which is derived from their highly ordered microstructures. The cured products can be easily reprocessed through imine metathesis and transesterification, and decomposed products can be obtained through imine hydrolysis under acidic or basic conditions and subsequently be re-cured. Surprisingly, recycled materials can be repeatedly reprocessed or chemically decomposed. The reprocessed materials retain the properties of their pristine counterparts, and the recycled products preserve the advantages of the hard thermosets without alteration to any of their unique properties. A dehydration reaction occurs between the residual hydroxyl groups during the re-hardening, which dramatically increases the glass transition temperature by ≈60 °C. These reprocessable and recyclable vitrimers demonstrate the effectiveness and environmental friendliness of the molecular design strategy reported herein.

Tailoring Dense, Orientation-Tunable, and Interleavedly Structured Carbon-Based Heat Dissipation Plates

The controllability of the microstructure of a compressed hierarchical building block is essential for optimizing a variety of performance parameters, such as thermal management. However, owing to the strong orientation effect during compression molding, optimizing the alignment of materials perpendicular to the direction of pressure is challenging. Herein, to illustrate the effect of the ordered microstructure on heat dissipation, thermally conductive carbon-based materials are fabricated by tailoring dense, orientation-tunable, and interleaved structures. Vertically aligned carbon nanotube arrays (VACNTs) interconnected with graphene films (GF) are prepared as a 3D core-ordered material to fabricate compressed building blocks of O-VA-GF and S-VA-GF. Leveraging the densified interleaved structure offered by VACNTs, the hierarchical O-VA-GF achieves excellent through-plane (41.7 W m^-1 K^-1 ) and in-plane (397.9 W m^-1 K^-1 ) thermal conductivities, outperforming similar composites of S-VA-GF (through-plane: 10.3 W m^-1 K^-1 and in-plane: 240.9 W m^-1 K^-1 ) with horizontally collapsed carbon nanotubes. As heat dissipation plates, these orderly assembled composites yield a 144% and 44% enhancement in the cooling coefficient compared with conventional Si₃ N₄ for cooling high-power light-emitting diode chips.

Enhanced Thermal Conductivity of Epoxy Composites by Introducing 1D AlN Whiskers and Constructing Directionally Aligned 3D AlN Filler Skeletons

With the miniaturization of current electronic products, ceramic/polymer composites with excellent thermal conductivity have attracted increasing attention. For regular ceramic particles as fillers, it is necessary to achieve the highest filling fraction to obtain high thermal conductivity, yet leading to higher production cost and reduced mechanical properties. In this paper, AlN whiskers with a high aspect ratio were successfully prepared using a modified direct nitriding method, which was further paired with AlN particles as fillers to prepare the AlN/epoxy composites. It is indicated that AlN whiskers could form bridging links between AlN particles, which favored the establishment of thermal pathways inside the polymer matrix. On this basis, we constructed the 3D AlN skeletons as a thermal conductivity pathway by the freeze-casting method, which could further enhance the thermal conductivity of the composites. The synergistic enhancement effect of 1D AlN whiskers and directional filler skeletons on the composite thermal conductivity was further demonstrated by the actual heat transfer process and finite element simulations. More significantly, the experimental results showed that the addition of one-dimensional fillers could also effectively improve the thermal stability and mechanical properties of the composites, which was beneficial for preparing high-performance TIMs.

Superior Thermal Conductivity of Graphene Film/Cu-Zr Alloy Composites for Thermal Management Applications

As the power density of electronic devices continuously increases, there is a growing demand to improve the heat conduction performance of thermal management materials for addressing heat dissipation issues. Single-/few-layer graphene is a promising candidate as a filler of a metal matrix due to its extremely high thermal conductivity (k); however, the well-arranged assembly of 2D-component graphene with a high volume fraction remains challenging. Herein, we integrated a novel graphene-based macroscopic material of graphene film (GF) into a Cu matrix by infiltrating molten Zr-microalloyed Cu into a spirally folded and upright-standing GFs skeleton. The microstructure of the GF/Cu composites was regulated by an interface modification strategy. The GF/Cu composites with a spirally layered microstructure exhibit a superior k of 820 W/m K in the axial direction, much higher than that of Cu-matrix composites reinforced with graphene nanosheets (generally <500 W/m K) and twice that of Cu. The thermal transfer mechanisms were investigated by experiments and theoretical calculations. The results reveal that the excellent performance is attributed to the construction of high-heat conduction channels and a positive coordinating effect at the Zr-modified GF/Cu interface. Meanwhile, the relation between interfacial microstructure and heat transfer is established in the composites using interfacial thermal resistance as a bridge. This work yields in-depth insight into the heat conduction mechanism in highly oriented structures and provides a promising solution for the thermal management issues of high-power electronics.

Multifunctional Epoxy-Based Electronic Packaging Material MDCF@LDH/EP for Electromagnetic Wave Absorption, Thermal Management, and Flame Retardancy

The sharp reduction in size and increase in power density of next-generation integrated circuits lead to electromagnetic interference and heat failure being a key roadblock for their widespread applications in polymer-based electronic packaging materials. This work demonstrates a multifunctional epoxy-based composite (MDCF@LDH/EP) with high electromagnetic wave (EMW) absorption, thermal conductivity, and flame retardancy performance. In which, the synergistic effect of porous structure and heterointerface promotes the multiple reflection and absorption, and dielectric loss of EMW. A low reflection loss of -57.77 dB, and an effective absorption bandwidth of 7.20 GHz are achieved under the fillings of only 10 wt%. Meanwhile, a 241.4% enhanced thermal conductivity of EP is due to the high continuous 3D melamine-derived carbon foams (MDCF), which provides a broad path for the transport of phonons. In addition, MDCF@LDH/EP composite exhibits high thermal stability and flame retardancy, thanks to the physical barrier effect of MDCF@LDH combined with the high temperature cooling properties of NiAl-LDH-CO₃ ^2- . Compared with pure epoxy resin, the peak heat release rate and the total heat release rate are reduced by 19.4% and 30.7%, respectively. Such an excellent comprehensive performance enables MDCF@LDH/EP to a promising electronic packaging material.

Use of biochar co-mediated chitosan mesopores to encapsulate alkane and improve thermal properties

Phase-change materials (PCMs) plays a significant role in energy conservation and thermal management systems. However, excessive seepage and insufficient thermal conductivity of pristine PCMs are restricting its real-world applications. Herein, "anisotropic-like" biochar with favorable pore characteristics is designed by combining it with chitosan for dodecane encapsulation. The use of biochar could overcome high manufacturing costs and associated environmental issues of PCM supporting materials. Biochar co-mediated chitosan enrich the mesopore proportion (96.5%) and provide interactive synergistic architecture. The prepared composite PCM exhibited outstanding latent heat retention of 95.9% after repeated cycling, high loading ratio, enhanced thermal conductivity (0.373 W/(m·K)), leakage-free, and repeatable utilization properties above the melting point of pristine dodecane. A figure of merit of 33.94 × 10⁶ W² S/(m^4oC) was achieved, far surpassing that measure among reported biochar-based composite PCMs. This study provides insights into next-generation sustainable energy storage development for a key global sustainability goal.

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

Combining the advantages of high thermal conductivities and low graphene contents to fabricate polymer composites for applications in thermal management is still a great challenge due to the high defect degree of exfoliated graphene, the poor orientation of graphene in polymer matrices, and the horrible phonon scattering between graphene/graphene and graphene/polymer interfaces. Herein, mesoplasma chemical vapor deposition (CVD) technology was successfully employed to synthesize vertically aligned graphene nanowalls (GNWs), which are covalently bonded by high-quality CVD graphene nanosheets. The unique architecture leads to an excellent thermal enhancement capacity of the GNWs, and a corresponding composite film with a matrix of polyvinylidene fluoride (PVDF) presented a high through-plane thermal conductivity of 12.8 ± 0.77 W m^-1 K^-1 at a low filler content of 4.0 wt%, resulting in a thermal conductivity enhancement per 1 wt% graphene loading of 1659, which is far superior to that using conventional graphene structures as thermally conductive pathways. In addition, this composite exhibited an excellent capability in cooling a high-power light-emitting diode (LED) device under real application conditions. Our finding provides a new route to prepare high-performance thermal management materials with low filler loadings via the rational design of the microstructures/interfaces of graphene skeletons.

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

The multi-functionalization of polymer composites refers to the ability to connect multiple properties through simple structural design and simultaneously achieve multi-performance optimization. The large-scale design and mass production to realize the reasonable structure design of multifunctional polymer composites are urgently remaining challenges. Herein, the multifunctional MXene/graphene/polymer composites with three-dimensional thermally and electrically conductive network structures are fabricated via the utilization of the microstructure of the soft template, and a facile dispersion dip-coating approach. As a result, the polymer composites have a multi-performance improvement. At the MXene and graphene content of 18.7 wt%, the superior through-plane thermal conductivity of polymer composite is 2.44 W m^-1 K^-1, which is 1118% higher than that of the polymer matrix. The electromagnetic interference (EMI) shielding effectiveness of the sample reaches 43.3 dB in the range of X-band. And the mechanical property of the sample has advanced 4 times compared with the polymer matrix. The excellent EMI shielding and thermal management performance, along with the effortless and easy-to-scalable producing techniques, imply promising perspectives of the polymer composites in the next-generation smart electronic devices.

Bio-inspired Multifunctional Graphene-Epoxy Anticorrosion Coatings by Low-Defect Engineered Graphene

Although graphene has been regarded as the most ideal anticorrosion filler, to date, some vital problems including poor dispersion, disordered arrangement, structure defects, and galvanic corrosion remain unresolved,, thus blocking its potential application in metal protection. In this work, a bio-inspried multilayered graphene-epoxy composite coating was fabricated through a scalable spraying approach with well-dispersed low-defect engineered graphene as the functional filler. Polydopamine served as an enforcer to improve the dispersity and repair the structure defects of graphene (π-π interaction) and bridged the dense graphene layers and epoxy layers (strong adhesion) for forming "interlock" structures to ensure complete coating systems. Electrochemical tests confirmed that the bio-inspired composite coating showed elevated coating resistance from 4.2 × 10⁶ Ω cm² for blank coating and 2.5 × 10⁸ Ω cm² for blending composite coating to 3.0 × 10⁹ Ω cm². The highly anisotropic graphene layers endowed the bio-inspried coating with highly anisotropic thermal and electrical conductivities, with the in-plane and through-plane thermal conductivities being 0.78 and 0.21 W/mK, respectively. Besides, the good anisotropic conductivities make the bio-inspired coating achieve self-monitoring of structural safety and health. This bio-inspired strategy provides a fascinating method for constructing high-performance graphene composite coatings with functional properties.

High intrinsic thermally conductivity side-chain liquid crystalline polysiloxane films grafted with pendent difunctional mesogenic groups

Herein, the microscopic ordered aggregation morphologies of SCLCP films are investigated, and molecular structures with regular arrangement can increase heat transfer via suppressing the scattering of phonons, thus greatly improving the λ of SCLCPs.

Millefeuille-Inspired Thermal Interface Materials based on Double Self-Assembly Technique for Efficient Microelectronic Cooling and Electromagnetic Interference Shielding

Owing to the increasing power density of miniaturized and high-frequency electronic devices, flexible thermal interface materials (TIMs) with the electromagnetic interference (EMI) shielding property are in urgent demand to maintain the system performance and reliability. Recently, carbon-based TIMs receive considerable attention due to the ultrahigh intrinsic thermal conductivity (TC). However, the large-scale production of such TIMs is restricted by some technical difficulties, such as production-induced defects of graphite sheets, poor microstructure architecture within the matrix, and nonnegligible interfacial thermal resistance result from the strong phono scattering. In this work, inspired by the structure and production process of millefeuille cakes, a unique double self-assembly strategy for fabricating ultrahigh thermal conductive TIMs with superior EMI shielding performance is demonstrated. The percolating and oriented multilayered microstructure enables the TIM to exhibit an ultrahigh in-plane TC of 233.67 W m^-1 K^-1 together with an outstanding EMI shielding effectiveness of 79.0 dB (at 12.4 GHz). In the TIM evaluation system, a nearly 45 °C decrease is obtained by this TIM when compared to the commercial material. The obtained TIM achieves the desired balance between thermal conduction and EMI shielding performance, indicating broad prospects in the fields of military applications and next-generation thermal management systems.

Interfacial Modulation of Graphene by Polythiophene with Controlled Molecular Weight to Enhance Thermal Conductivity

With a trend of continuing improvement in the development of electronic devices, a problem of serious heat accumulation has emerged which has created the need for more efficient thermal management. Graphene sheets (GNS) have drawn much attention with regard to heat transfer because of their excellent in-plane thermal conductivity; however, the ultrahigh interfacial thermal resistance between graphene lamellae has seriously restricted its practical applications. Herein, we describe heat transfer membranes composed of graphene which have been modified by intrinsic thermally conductive polymers with different molecular weights. The presence of macromolecular surface modifiers not only constructed the graphene heat transfer interface by π-π interactions, but also significantly enhanced the membranes' in-plane thermal conductivity by utilizing their intrinsic heat transfer properties. Such results indicated that the in-plane thermal conductivity of the fabricated membrane exhibits a high in-plane thermal conductivity of 4.17 W m-1 K-1, which, containing the GNS modified with 6000 g/mol (Mn) of poly(3-hexylthiophene) (P3HT), was 26 times higher that of poly (vinylidene fluoride) (PVDF). The P3HT molecular chain with specific molecular weight can form more matching structure π-π interactions, which promotes thermal conductivity. The investigation of different molecular weights has provided a new pathway for designing effective interfacial structures to relieve interface thermal resistance in thermally conductive membranes.