Thermal Conductivity Enhancement Research Articles

Controllable exfoliation of hexagonal boron nitride and tailored three‐dimensional network for highly thermally conductive polymer composites

AbstractThermally conductive but electrically insulating composites have become significant components for efficient thermal dissipation in electronic devices due to their miniaturization, integration, and functionalization. Over the past decade, extensive efforts have been dedicated to improving the thermal conductivity of polymer‐based composites through incorporating various thermally conductive fillers. In particular, boron nitride nanosheets (BNNS) with outstanding intrinsic thermal conductivity, electrical insulation, and chemical stability, have sparked intensive interest from researchers. However, BNNS usually suffers from severe aggregation in polymer matrices, leading to high interfacial thermal resistance. Rational construction of three‐dimensional (3D) BNNS continuous networks is crucial for efficient thermal transport and has also been established as a feasible and effective approach to achieve significant enhancement of thermal conductivity for polymer/BNNS composites. In this brief review, we summarized and introduced recent progress on the controllable exfoliation of h‐BN and tailored three‐dimensional networks for highly thermally conductive polymer composites. The fabrication strategies for 3D BNNS networks and the structure–properties relationships of polymer/BNNS composites are highlighted. Finally, the opportunities and challenges for polymer/BNNS composites based on 3D thermally conductive networks are prospected.

Effect of interface layer on the enhancement of thermal conductivity of SiC-Water nanofluids: Molecular dynamics simulation

To investigate the impact of interfacial layer effects on the thermal conductivity of nanofluids and the microscopic mechanisms of enhanced thermal conductivity, this study employed non-equilibrium molecular dynamics to compute the thermal conductivity, number density, radial distribution function, and mean square displacement distribution of SiC nanofluids. The impact of nanoparticle volume fraction and particle size parameters on the thermal conductivity of nanofluids and the structure of interfacial adsorption layers was discussed. The simulation calculation results show that the coefficient of thermal conductivity of nanofluid is positively related to the volume fraction of nanoparticles, increasing from 0.6529 W/(m·K) to 0.8159 W/(m·K), and the enhancement of thermal conductivity by the volume fraction can be up to 33.97 %. The thermal conductivity is inversely correlated with the change in particle size, and the maximum improvement in thermal conductivity by particle size can reach up to 12.05 %. The simulated results of the thermal conductivity of nanofluid are almost consistent with the predicted results of the Yu&Choi model, and the error is controlled within 5 %. Simultaneously, the thickness of the interfacial adsorption layer decreases with an increase in particle size. This reduction arises due to larger particles having a smaller specific surface area, resulting in fewer particle surfaces covered by the interface layer. Moreover, the impact of particle size on the arrangement and affinity of molecules within the interface layer contributes to this decrease. Overall, interface layer effects exhibit a dual impact on the thermal conduction of nanofluids. The structured formation and high-density distribution of the adsorption layer contribute to enhanced heat transfer, while thermal resistance between nanoparticle surfaces and the fluid restricts heat transmission.

Enhancing Thermal Conductivity, Electrical Insulation, and Mechanical Strength of Polydimethylsiloxane Composites with Sandwich Structure

In this article, boron nitride (BN)/carbon nanotube (CNT)/boron nitride (BN) (BCB) film of sandwich structure is prepared by vacuum‐assisted filtration. Compared with the thermal conductivity (λ) of BNs–cellulose nanocrystals (CNCs) (BC) film, the λ of sandwich structured BCB films with the same thickness (The preparation process consists of one layer of BC and one layer of CNTs–CNCs (CC) until the completion of three layers of filtration) has been significantly improved. Then, the polydimethylsiloxane (PDMS) matrix is infiltrated into the BCB films by the ultrasonic‐assisted forced infiltration method. Prepared BN/CNT/BN/PDMS (BCBP) composites with sandwich structure have excellent λ and mechanical performance. When the weight ratio of BNs to CNCs is 20:1, the λ of BCBP20:1 attains 5.253 W (m K)−1, compared with other thermally conductive composites with the same thickness (0.1 mm), it has an obvious increase. Besides, the dielectric properties and mechanical flexibility of BCBP are also systematically analyzed. This sandwich structure is prepared in such a method that the BCBP will not cause short circuits in electronic devices under high temperatures while having high λ.

Rotational stress-induced shish-kebab governs the balance of enhanced thermal conductivity and mechanical performance of high-density polyethylene (HDPE) / boron nitride (BN) composites via axial hot compression

Polymer-based composites with high BN sheets loadings have potential to improve thermal conductivity without compromising mechanical performance. In this work, a balanced enhancement in both thermal conductivity and tensile strength were achieved using rotational shear followed by axial hot compression. For neat HDPE matrix, the highly oriented shish-kebab structures induced by shear field improved tensile strength from 20.4 MPa to 80.9 MPa, compared with unsheared specimens. The in-plane thermal conductivity of sheared HDPE/BN composite was 25.0% higher than the unsheared one. Axial hot compression resulted in denser crystal and oriented fillers, leading to a 63% increase in tensile strength while simultaneously increasing thermal conductivity in both in-plane and out-plane directions. This work has utilized rotation shear and axial hot compression to manufacture HDPE/BN composites with effective two-way thermal conductivity and higher tensile strength. The excellent thermo-mechanical properties mean a longer service time and less replaced frequency of material under extreme operating conditions. The two-step methods provide a key information for the preparation of composites with balanced mechanical properties and thermal conductivity.

Modulation of interface modes for resonance-induced enhancement of the interfacial thermal conductance in pillar-based Si/Ge nanowires

Modulation of interface modes for resonance-induced enhancement of the interfacial thermal conductance in pillar-based Si/Ge nanowires

Effect of different micelles on charging and discharging behavior of phase change material

Phase change material (PCM) offers high-density thermal energy storage, making it attractive for thermal management applications of electronic circuitry and thermal energy storage. However, PCM, like paraffin wax, ideal for such low-temperature applications, has very low thermal conductivity. The present study focused on the improvement of the thermal conductivity of paraffin wax using surfactants. The surfactants used as thermal conductivity enhancers (TCE) are cetyltrimethyl ammonium bromide (CTAB), Dioctyl sodium sulfosuccinate (known as AOT) and sodium dodecyl sulfate (SDS). The surfactant self-aggregation called a micelle, acts as conducting medium inside the paraffin wax, providing better thermal conductivity. The highest heat transfer rate with a peak temperature of 71 °C was observed in the case of AOT micelle paraffin wax. Adding SDS, CTAB, and AOT surfactants increased the highest temperatures by 4%, 8.4%, and 18.33% compared to pure PCM.

Graphene oxide – adipic acid nanocomposites for thermal energy storage: Assessment of thermophysical properties and energy storage performance

Adipic acid is one of the organic phase change materials with a melting temperature greater than 150 °C and a freezing point greater than 140 °C, making the same a suitable thermal energy storage medium for near-atmospheric pressure steam generation. This work attempts to alleviate the rate limitation posed by the lower thermal conductivity of adipic acid by adding graphene oxide (GO) nanostructures at lower concentrations such that the energy storage capacity is not severely affected. The resultant GO – adipic acid composites (0–2 wt% GO) were characterized in terms of latent heat for phase change, specific heat and thermal conductivity. The composite containing 1 wt% GO exhibited a 16 % enhancement in thermal conductivity with a 3.4 % reduction in latent heat and 3.6 % reduction in specific heat. The impact of GO addition on the solidification rate was remarkable, with a 44 % enhancement in overall heat transfer coefficient during the initial solidification phase, when solidification was carried out in thermal contact with a constant temperature heat transfer fluid (oil bath). Thus, the present work clearly demonstrates the intensification of heat transfer during the discharge cycle of a thermal energy system with 1 wt% GO-Adipic acid composite as the thermal energy storage medium.

Magnetic field dependent thermal conductivity investigation of water based Fe3O4/CNT and Fe3O4/graphene magnetic hybrid nanofluids using a Helmholtz coil system setup

Magnetic hybrid nanofluids are making a name of themselves in mainstream application areas such as heat transfer, solar systems, acoustic applications, etc. These nanofluids are highly favorable as their ability to advance the properties of their constituent particles such as their thermophysical properties. This study aims to investigate the magnetic field dependent thermal conductivity of Fe3O4/CNT – water and Fe3O4/Graphene – water magnetic hybrid nanofluids. The thermal conductivity investigations are carried out with the 3ω method under a uniform magnetic field generated by a 3D Helmholtz coil system. Fe3O4/CNT – water and Fe3O4/Graphene – water magnetic hybrid nanofluids were purchased commercially as 20 wt% colloids. Then, the samples with 1, 2, 3, 4, and 5 wt% were prepared by diluting them with DI water. Thermal conductivity measurements were carried out for the samples under the external uniform magnetic field in the range of 0–250 G in both parallel and perpendicular directions to the temperature gradient generated by the thermal conductivity measurement probe. The results pointed out that the thermal conductivity of the samples increases as the magnetic field and particle concentration increase for both magnetic hybrid nanofluids. Additionally, it is obtained that the thermal conductivity enhancement of Fe3O4/Graphene – water is up to 3 times higher than Fe3O4/CNT – water samples. Moreover, the maximum thermal conductivity enhancement was observed as ∼12 % and ∼9 % for Fe3O4/CNT – water, and ∼51 % and ∼21 % Fe3O4/Graphene – water under external magnetic field application with parallel and perpendicular direction, respectively.

Fabrication and thermal properties of capric–stearic acid eutectic/nano-SiO2 phase change material with expanded graphite and CuO for thermal energy storage

With the booming development of energy storage technology, phase change materials (PCMs) provide more possibilities for building energy efficiency. In this paper, binary eutectic mixture of capric acid (CA) and stearic acid (SA) is PCM, nano silica (SiO2) is used as the nano-enhancer, and expanded graphite (EG) and nano CuO are used as the thermal conductivity enhancers. Different mass fractions of composite phase change materials (CPCMs) are prepared by melt impregnation method. The structure, thermal properties, stability, thermal conductivity properties, thermal storage/release properties and temperature response properties of the CPCMs are characterized. Results show the prepared CA-SA/SiO2/EG(CPCM5) melts at 30.62 °C and solidifies at 25.29 °C with latent heat of 156.50 J/g and 144.20 J/g, respectively, and CA-SA/SiO2/CuO(CPCM8) melts at 29.09 °C and solidifies at 25.30 °C with latent heat of 152.60 J/g and 140.70 J/g, respectively. The latent heats of melting are higher than the theoretical latent heat due to the enhancement of the nano SiO2. Good compatibility is observed between CA-SA, SiO2, CuO and EG. The thermal conductivity of CPCM8 and CPCM5 are 0.287 and 0.929 W/(m·K), respectively, and CPCM5 has better thermal storage/release and temperature response characteristics. Moreover, CPCM5 does not decompose at 100.00 °C, and shows good stability after 200 cycles of heating and cooling. Therefore, the composite has great potential for application in the field of building energy efficiency.

Preparation and application of rice husk-based SiO2/water nanofluids in heat transfer enhancement under pulsation

Rice husk was used as raw-material to produce nano-SiO2 by the heat treatment method, and the structural characteristics of rice husk SiO2 (R-SiO2) was compared with the commercial SiO2 (C-SiO2) by various characterization methods. SiO2/water nanofluids were prepared by a two-step dispersion method using various sources SiO2 (R-SiO2 and C-SiO2) and applied in the convective heat transfer of corrugated tube channels in a self-built experimental platform. The experimental results showed that the specific surface area of the rice husk-based silica was high, reaching 335 m2/g. For the same nanofluids concentration, the thermal conductivity enhancement rate of R-SiO2/water nanofluid was higher than that of C-SiO2/water and the enhancement rate of 0.5% R-SiO2/water at 25 and 40 °C reached 14.01% and 12.16%, respectively. The convective heat transfer coefficient of R-SiO2/water was slightly better than that of commercial C-SiO2/water, which indicated that R-SiO2 has great potential to be a substitute of C-SiO2 for application in heat exchangers. The convective heat transfer characteristics of R-SiO2/water nanofluids in corrugated tube at different Re and volume concentrations were compared. It was found Nu augmented as Re increased. And a higher nanofluids concentration might result in a drastic increment in convective heat transfer coefficient. When a pulsating wave was imposed, the larger pulsation amplitude resulted in a higher heat transfer enhancement rate. And the enhancement rate at lower Re was better. Under the conditions of Re = 385, f = 0.67 and A = A15, the maximum average convective heat transfer enhancement rate reached 143%.

Phonon thermal transport in ferroelectric α-In2Se3 via first-principles calculations

Two-dimensional (2D) ferroelectrics are promising candidates in the field of microelectronics due to their unique properties such as excellent photoelectric responsiveness. However, the thermal properties of 2D ferroelectrics are less investigated. Here, the thickness dependent thermal conductivity in ferroelectric α-In2Se3 is systematically investigated by the first-principles method combined with the phonon Boltzmann transport equation. On this basis, the strain and oxidation effects on the thermal conductivity of monolayer α-In2Se3 is further studied. The calculation results show that the thermal conductivity has a significant reduction with decreasing film thickness or increasing tensile strain, and the anharmonic phonon–phonon scattering rate is the intrinsic mechanism for the reduction in thermal conductivity. On the other hand, the replacement of Se atoms by O atoms can achieve a bidirectional and wide-range (12×) tuning of thermal conductivity. The increase in specific heat and phonon group velocity is responsible for the thermal conductivity enhancement at high doping levels while that in phonon–phonon scattering rate is responsible for the thermal conductivity reduction at low doping levels. In all cases, acoustic phonons dominate the in-plane thermal transport behavior. These findings broaden our understanding of phonon transport and its control in ferroelectric semiconductor α-In2Se3.

Thermal performance of novel ZnFe2O4 and TiO2-doped MWCNT nanocomposites in transformer oil

Efficient heat transfer and optimal dielectric properties are pivotal factors in ensuring the reliability and longevity of transformers, essential components in modern power systems. This study aimed to harness the potential of nanofluids to enhance both heat transfer and dielectric characteristics of transformer oil (TRO), addressing the challenges posed by increasing energy demands. A comprehensive investigation was conducted involving the synthesis of nanofluids with distinct nanoparticle compositions and concentrations. The experimental approach encompassed diverse characterization methods, namely SEM, EDX, zeta potential analysis, DLS, and FT-IR. These techniques were employed to gain insights into the prepared nanofluids’ structural, elemental, and thermal properties, facilitating a comprehensive understanding of their behavior. Notably, the incorporation of nanoparticles led to substantial enhancements in thermal conductivity and volumetric-specific heat of the nanofluids. Convective heat transfer coefficients (CHTC) and Nusselt numbers (Nu) were evaluated under forced convection conditions, revealing improvements ranging from 9% to 21%. These findings highlight the potential for nanofluids to significantly enhance heat transfer efficiency, which is crucial for efficient transformer operation. Furthermore, the breakdown voltage (BDV) investigation identified strategies to counter BDV reduction by employing nanoparticles within nanocomposites. This approach aimed to improve the dielectric performance of the nanofluids, a critical aspect of maintaining transformer insulation. These findings bridge the gap between advanced nanotechnology and practical applications in power systems, providing insights into enhancing transformer efficiency and reliability.

Enhancing thermal energy storage in buildings with novel functionalised MWCNTs-enhanced phase change materials: Towards efficient and stable solutions

Phase change materials (PCMs) are a promising panacea to tackle the intermittency of renewable energy sources, but their thermal performance is limited by low thermal conductivity (TC). This pioneering work investigates the potential of organic PCM-enriched surface-modified and un-modified multi-walled carbon nanotubes (MWCNTs) for low-temperature thermal energy storage (TES) applications. The functionalised and un-functionalised MWCNTs enhanced PCM have demonstrated a TC enhancement of 158 % and 147 %, respectively, at 25 °C. However, the TC value of the unmodified MWCNTs-based PCM dropped by 52.5 % after 48 h at 25 °C, while that of the functionalised MWCNTs-based PCM remained stable. A DSC analysis of up to 200 thermal cycles confirmed that the surface-modified and un-modified MWCNTs had no major effect on the peak melting and cooling temperatures of the nano-enhanced PCMs although a minor decrease of 7.5 % and 7.7 % in the melting and crystallisation enthalpies, respectively, was noticed with the inclusion of functionalised MWCNTs. Moreover, functionalised MWCNTs incorporated PCMs have led to increases in specific heat capacity by 23 % with an optimal melting enthalpy value of 229.7 J/g. In addition, no super-cooling, no phase segregation, and a small phase change temperature were noticed with these nano-enhanced PCMs. Finally, no chemical interaction from nano-PCMs was seen in the FT-IR spectra with the incorporation of both functionalised and un-treated MWCNTs. It is evident that the functionalised MWCNT-based PCM has better thermal stability and it offers a promising alternative for improving thermal storage and management capabilities in buildings, contributing to a sustainable and energy-efficient building design.

Storage performance of a novel array metal hydride hydrogen storage reactor based on PCM thermal management

Metal hydrides (MH) are an attractive option for solid hydrogen storage with the large thermal effects of their hydrogen absorption and desorption processes when used in reactors. Phase-change materials (PCM) have been used as thermal management media in the MH reactor. To further improve the performance of the reactor, this study proposed a novel PCM-based MH reactor with array layouts, aiming to construct a heat transfer interface with a high specific surface area. A mathematical model was constructed to elucidate the phenomenon of heat transmission and absorption reaction. It was found that an increase in the number of array units significantly increased the heat transfer area but had a limited impact on enhancing the absorption rate and heat transfer. Nevertheless, the array reactor with seven units had a significant 1.0 times increase in the absorption rate compared to the traditional reactor with only one array unit. Furthermore, the enhancement of thermal conductivity in MH/PCM and the elevation of hydrogen supply pressure have the potential to accelerate the reaction rate and heat transfer during absorption. The enhanced absorption pressure not only enhances the driving force of the reaction directly but also amplifies the temperature difference in heat transfer between PCM and MH. Consequently, this leads to a further improvement in heat transfer and reaction efficiency.

Effect of Al2O3 nanoparticle dispersion on the thermal properties of a eutectic salt for solar power applications: Experimental and molecular simulation studies

Thermophysical properties of molten salts aid in determining the storage efficiency of thermal energy storage (TES) systems in concentrating solar power plants. In this research, a novel ternary molten salt (4NaCl–37KCl–59LiNO3, mol%) was utilized as the phase change material (PCM), while Al2O3 nanoparticles (NPs) were employed as a thermal conductivity enhancer. Experimental measurements and molecular dynamics simulations were conducted to confirm that the introduction of Al2O3 NPs as dopants enhanced the specific heat, thermal conductivity, and energy storage density of the eutectic salt. Specifically, at an Al2O3 NP content of 0.5 wt%, the composite PCM exhibited a 44.23 % increase in liquid-state specific heat and a 40.82 % increase in liquid-state thermal conductivity, along with a 15.73 % increase in storage density. This study demonstrates that the enhanced thermal properties of eutectic salts by adding Al2O3 NPs are primarily attributed to the emergence of nanostructures and alterations in atomic potential energy, as evidenced by both experimental and simulated microstructural analyses. These findings offer valuable insight into the selection of thermal storage materials and additives, as well as their implementation in medium-temperature TES systems, with the objective of optimizing the efficient utilization of solar energy.

Enhanced Thermal Conductivity of Single-Walled Carbon Nanotube with Axial Tensile Strain Enabled by Boron Nitride Nanotube Anchoring.

Thermal conductivity measurements are conducted by optothermal Raman technique before and after the introduction of an axial tensile strain in a suspended single-walled carbon nanotube (SWCNT) through end-anchoring by boron nitride nanotubes (BNNTs). Surprisingly, the axial tensile strain (<0.4 %) in SWCNT results in a considerable enhancement of its thermal conductivity, and the larger the strain, the higher the enhancement. Furthermore, the thermal conductivity reduction with temperature is much alleviated for the strained nanotube compared to previously reported unstrained cases. The thermal conductivity of SWCNT increases with its length is also observed.

Interfacial nanolayer effect on thermophysical properties of silica-paraffin phase change material - A molecular dynamics simulation

Thermophysical properties of composite phase change materials (PCMs) are influenced by the interfacial nanolayer. Molecular dynamics (MD) method is used to study the effect of interfacial nanolayer on thermophysical properties of silica-paraffin composite PCM. The simulation results show that the melting enthalpy is reduced from 197.9 J·g−1 to 29.1 J·g−1, and the thermal conductivity is enhanced from 0.142 W·m−1·K−1 to 0.268 W·m−1·K−1, when the silica thickness is increased from 0 to 15.0 Å. The interfacial nanolayer is observed in composite PCM, and its thickness increases with the increase of silica wall thickness. In the composite PCM with 7.0 Å silica wall, a loss of 62.9% in the melting enthalpy is observed, with 32.6% attributed to the silica mass and 30.3% attributed to the nanolayer. Based on that, a modified model is proposed to predict the melting enthalpy of composite PCMs by considering the effects of both silica mass fraction and nanolayer. To reveal the thermal conductivity enhancement mechanism, the total heat flux is decomposed into three terms (namely, kinetic energy term, potential energy term and interaction energy term). It is found that the interaction energy term has the largest contribution to the total heat flux. The presence of nanolayer strengths the interactions, leading to the thermal conductivity enhancement.

Design of BCNO@PPy composites for efficient microwave absorption and thermal management

Currently, multifunctional microwave-absorbing materials, especially those with thermal conductivity and microwave absorption functions, have excellent application prospects in electronic packaging. In this study, we first used a sacrificial template method to prepare BCNO using biomass carbon as a template. Then, we used an in-situ synthesis method to grow polypyrrole (PPy) on the surface of BCNO to prepare BCNO@PPy with a core-shell structure. The BCNO@PPy composite exhibits a minimum reflection loss (RLmin) of −52.6 dB at a thickness of only 1.94 mm and an effective absorption bandwidth (EAB) of 5.3 GHz (12.7–18 GHz). The excellent microwave absorption can be attributed to the synergistic effect of polarization loss, conductive loss, and partial magnetic loss in the BCNO@PPy (BPPy) composites, and the multi-wall reflection effect of the core-shell structure, as well as the excellent impedance matching of the composites. Notably, BPPy-3 (polypyrrole content of 28.5 wt%) showed a good thermal conductivity enhancement effect on the epoxy resin (EP) when the content of BPPy-3 was 30 wt%. BPPy-3/EP has a thermal conductivity of 1.82 W(m·K)−1, which is 619.5 % higher than that of pure EP. The good thermal conductivity of the composites is attributed to the excellent compatibility of PPy and epoxy resin, as well as the low interfacial thermal resistance between BCNO and PPy. Therefore, this work can provide a reference for the design of materials with both thermal conductivity and microwave absorption functions.

Enhanced Thermal Properties of Phase Change Materials through Surfactant-Functionalized Graphene Nanoplatelets for Sustainable Energy Storage

Phase change materials (PCMs) are increasingly gaining prominence in thermal energy storage due to their impressive energy storage capacity per unit volume, especially in applications with low and medium temperatures. Nevertheless, PCMs have significant limitations regarding their ability to conduct and store heat, primarily due to their inadequate thermal conductivity. One potential solution for improving the thermal conductivity of PCMs involves the inclusion of nanoparticles into them. However, a recurring issue arises after several thermal cycles, as most nanoparticles have a tendency to clump together and settle at the container’s base due to their low interfacial strength and poor compatibility. To address this challenge, including surfactants such as sodium dodecylbenzene sulfonate (SDBS) has emerged as a prevalent and economically viable approach, demonstrating a substantial impact on the dispersion of carbon nanoparticles within PCMs. The foremost objective is to investigate the improvement of thermal energy storage by utilizing graphene nanoplatelets (GNP), which are dispersed in A70 PCM at various weight percentages (0.1, 0.3, 0.5, 0.7, and 1.0), both with and without the use of surfactants. The findings indicate a remarkable enhancement in thermal conductivity when GNP with surfactants is added to the PCM, showing an impressive increase of 122.26% with a loading of 1.0 wt.% compared to conventional PCM. However, when 1.0 wt.% pure GNP was added, the thermal conductivity only increased by 48.83%. Additionally, the optical transmittance of the composite containing ASG-1.0 was significantly reduced by 84.95% compared to conventional PCM. Furthermore, this newly developed nanocomposite exhibits excellent stability, enduring 1000 thermal cycles and demonstrating superior thermal and chemical stability up to 257.51 °C. Due to its high thermal stability, the composite NePCM is an ideal candidate for preheating in industrial and photovoltaic thermal (PVT) applications, where it can effectively store thermal energy.

Coaxial Wet Spinning of Boron Nitride Nanosheet-Based Composite Fibers with Enhanced Thermal Conductivity and Mechanical Strength

HighlightsA core-sheath structured coaxial composite fiber with highly aligned and densely stacked boron nitride nanosheets arrangements in the sheath was successfully fabricated.The coaxial fibers have an ultrahigh axial Herman orientation parameter of 0.81, thermal conductivity of 17.2 W m−1 K−1, and tensile strength of 192.5 MPa.The coaxial fibers exhibit intensively potential applications in the wearable thermal management textile.