Interfacial Thermal Resistance Research Articles

Effect of graphene arrangement on the thermal conductivity of graphene/polymer nanocomposites

ABSTRACT Due to its high thermal conductivity (up to 5300 W/mK), graphene is considered an ideal filler for composites with a polymer matrix to form a thermal interface material with excellent thermal performance. The thermal conductivity of graphene/polymer nanocomposites can be effectively improved by increasing the aspect ratio of graphene, simultaneously increasing the lateral size and thickness of graphene at a constant aspect ratio or changing the ordered orientation of graphene nanosheets (GNSs) filled in the polymer matrix. Experimental results have shown that the ultrahigh thermal conductivity of the composites can be achieved in the in-plane direction due to the minimum interface thermal resistance along this direction. To detect the arrangement structure of GNSs on the thermal conductivity of the composites, this paper obtained the expressions of the effective thermal conductivity for anisotropic GNSs/polymer composites based on the multiple-scattering theory, where the effect of the number of GNSs layers on the interface thermal resistance and thermal conductivity of GNSs is considered. The numerical results show that the composites parallel to the aligned direction of GNSs have greater thermal conductivity than those perpendicular to it. The ordered orientation of GNSs can effectively improve the thermal conductivity for GNSs/polymer nanocomposites.

Facile chemical surface modification of boron nitride platelets and improved thermal and mechanical properties of their polymer compounds for 2.5D/3D packaging applications

Thermally conductive yet electrically insulative epoxy composites are sought after as encapsulation materials to tackle the heat dissipation challenges in modern electronics. In this work, we developed a novel one-step and facile solvothermal reflux method using a high-boiling-point solvent to surface-modify hexagonal boron nitride (h-BN) with glycine. By refluxing glycine at high temperature, amino functional groups are grafted onto the BN surface, which can enhance the affinity of fillers for epoxy and reduce the interfacial thermal resistance of the filler/epoxy composites. We investigated the mechanism of glycine-grafted layer formation, optimizing reactant mass ratios for enhanced interfacial thermal transport. The resulting BN@G11/epoxy composites exhibit a remarkable thermal conductivity of 1.04 W/mK at 30 wt% modified-BN loading, representing a 477.8 % increase over neat epoxy and 57.5 % higher than h-BN/epoxy composites at equivalent BN filler loading. Additionally, these composites demonstrate improved thermomechanical properties, confirming the strengthened BN/epoxy interface bonding using modified BN fillers. Compared to other surface treatment methods, this solvothermal reflux approach stands out for its scalability and cost-effectiveness. This scalable and eco-friendly innovation presents a competitive strategy for designing polymer-based composites for thermal management, catering to the demands of future 2.5D/3D semiconductor packaging.

Thermally conductive silver adhesive enhanced by MXene@AgNPs with excellent thermal conductivity for thermal management applications

The Thermal Conductive Silver Adhesive (TCSA) efficiently transfers heat from electronic components to heat dissipation components, preventing overheating and extending device lifespan. Despite the effectiveness of commercial sintered nano TCSA, high production costs necessitate a more affordable, high-performance preparation method. This study presents a strategy for preparing ultra-high thermal conductivity (TC) TCSA using multidimensional thermal conductive fillers and low-temperature sintering of silver nanoparticles (AgNPs). MXene@AgNPs particles are synthesized via in-situ reduction of AgNPs on MXene surfaces. These particles, combined with silver microflakes (AgMFs) as primary fillers and epoxy (EP), undergo low-temperature heat treatment to form the AgMFs-MXene@AgNPs/EP composite. Characterization and computational models show that filler-filler interface thermal resistance (ITRf-f) is critical for TC. Adding MXene alone is insufficient, but using MXene@AgNPs particles as secondary fillers allows AgNPs to interconnect fillers, effectively reducing the ITRf-f. The resulting composite achieves an ultra-high TC of 65.51 Wm−1K−1 with 63 wt% total filler content (60 wt% AgMFs, 3 wt% MXene@AgNPs). This study advances the development of low-cost, high-performance TCSA for thermal management applications.

Seeking non-Fourier heat transfer with ultrabroad band thermoreflectance spectroscopy

Studying superdiffusive thermal transport is crucial for advanced thermal management in electronics and nanotechnology, ensuring devices run efficiently and reliably. Such study also contributes to the design of high-performance thermoelectric materials and devices, thereby improving energy efficiency. This work leads to a better understanding of fundamental physics and non-equilibrium phenomena, fostering innovations in numerous scientific and engineering fields. We are showing, from a one shot experiment, that clear deviations from classical Fourier behavior are observed in a semiconductor alloy such as InGaAs. These deviations are a signature of the competition that takes place between ballistic and diffusive heat transfers. Thermal propagation is modelled by a truncated Lévy model. This approach is used to analyze this ballistic-diffusive transition and to determine the thermal properties of InGaAs. The experimental part of this work is based on a combination of time-domain and frequency-domain thermoreflectance methods with an extended bandwidth ranging from a few kHz to 100 GHz. This unique wide-bandwidth configuration allows a clear distinction between Fourier diffusive and non-Fourier superdiffusive heat propagation in semiconductor materials. For diffusive processes, we also demonstrate our ability to simultaneously measure the thermal conductivity, heat capacity and interface thermal resistance of several materials over 3 decades of thermal conductivity.

High thermal conductivity and low dielectric loss of three-dimensional boron nitride nanosheets/epoxy composites

Electronic power devices are moving towards high frequency, high integration, and high power, which urgently needs to develop high thermal conductive encapsulating insulation materials to improve the heat dissipation of electronic devices. Herein, we propose to modify the commercialized encapsulating materials of epoxy resin (EP) by incorporating three-dimensional hydroxylated boron nitride nanosheets (3D-BNNSs). The cryogel and vacuum freeze-drying techniques are employed to prepare the 3D-BNNSs using agarose. The results show that the constructed high thermal conductive structure of 3D-BNNSs can effectively enhance the thermal conductivity of EP and reduce the interfacial thermal resistance between BNNSs fillers. The thermal conductivity of 3D-BNNSs/EP composites with 33.03 wt% BNNSs reach 2.54 W/(m·K), which is 13.11 times higher than that of EP (0.18 W/(m·K)). Meanwhile, the resultant composites remain outstanding electrical insulation and dielectric properties. Because agarose contains numerous hydroxyl groups that can form hydrogen bonds with the hydroxyl groups on the surface-functionalized BNNSs, hydrogen bonding can lead to strong intermolecular interactions, which is conductive to accelarate phonon transport. Additionally, agarose can cross-link with the molecular chains of epoxy, impeding the movement of molecular chain segments and resulting in composites with low dielectric loss at high frequencies. This study demonstrates that the 3D-BNNSs/EP composites have great potential for application in thermal management of electronic components.

Covalent bond-assisted continuous interface structure for high thermal conductive polyimide composite films

Polyimide (PI) is widely used in electronic, electrical and communication fields because of its outstanding mechanical properties, electrical insulation and thermal stability. However, the lower thermal conductivity limits their application. Here, PI composite films with high thermal conductivity are obtained by utilizing reactive groups on the carbon nitride nanosheets (CNNS) surface to form covalent bond with PI matrix. The thermal conductivity of CNNS/PI composite films can reach 5.84 W∙m−1∙K−1, which is about 10 times higher than that of pure PI (0.56 W∙m−1∙K−1). This is attributed to the covalent bond between CNNS and PI matrix acting as a “thermal bridge” to connect the discontinuities at the interface, thereby reducing the interfacial thermal resistance between CNNS and PI. The heat transfer mechanism of composite film is further revealed by finite element analysis. This work provides a viable solution to improve the thermal conductivity of PI, allowing for a wide range of potential applications for PI in electronic devices.

Novel phase‐change PDA‐Ni@GNS/CNF‐C/SA/PEG composites with ultrahigh shape stability and latent heat as thermal management material for microelectronic devices

AbstractPhase‐change materials (PCMs) have become a hot spot in the development of modern thermal management materials because of their absorbing and releasing heat while keeping the temperature constant during phase change process. However, their relatively low thermal conductivity (TC) considerably restricts their further application. In this work, graphene nanosheets (GNS) were initially nickel‐plated to increase the contact area between adjacent GNS (in the form of Ni@GNS) by constructing a “point‐surface” structure. Then, the prepared Ni@GNS was coated with polydopamine (PDA) to prepare PDA‐Ni@GNS, which helped to effectively reduce the interface thermal resistance (ITR) between the filler and the matrix, and also made the prepared filler more easily dispersed in the polymer matrix. By constructing well‐defined three‐dimensional (3D) thermally conductive pathways in the matrix, the PCMs exhibited excellent TC and effectively prevented the leakage of polyethylene glycol (PEG) even at low filler loading. The results of thermogravimetry (TG), differential scanning calorimeter (DSC), and cyclic DSC tests jointly showed that the PDA‐Ni@GNS/CNF‐C/SA/PEG PCMs displayed excellent thermal storage properties, high latent heat as well as good cyclic thermal stability. The present study provides a facile way of preparing PEG‐based PCMs, which are applicable in thermal management area.

Chemical heterogeneity size effects at nanoscale on interface thermal resistance of solid–liquid polymer interface via molecular dynamics simulations

The shrinking size of integrated chips poses thermal management challenges. Understanding the size effect of chemical heterogeneity on solid–liquid interfacial thermal transfer is essential for heterogeneous chip design, yet the underlying mechanisms remain lacking. The present work used the liquid n-alkanes as the thermal interface material between solid platinum substrates. To characterize chemical heterogeneity, periodic solid surface patterns composed of patches with alternating solid–liquid affinities were constructed. By using non-equilibrium molecular dynamics simulations, we investigated the size effect of chemically heterogeneous patterns on interfacial thermal resistance (ITR) at the nanoscale. At larger heterogeneity sizes, i.e., larger patch sizes, most alkane molecules directly in contact weak interaction patches cannot interact with strong interaction patches due to long atomic distances. In the case of alkanes in contact a cold substrate, alkanes in contact weak interaction patches transferred thermal energy to the substrate at a lower rate than those in contact strong interaction patches. The different rates resulted in the higher temperature of alkanes in contact weak interaction patches than those in contact strong interaction patches and, therefore, a larger disparity between temperature jump at the strong interaction areas and that at the weak interaction areas. The non-uniformity of temperature jump distribution increased ITR when compared to the heterogeneous surface system characterized by a smaller patch size with a more uniform temperature distribution in the plane perpendicular to the heat flux direction. In addition, the classical parallel thermal resistance model predicted ITR accurately for the heterogeneous surface systems with small size patches but overestimated overall thermal resistance.

Microstructure and performance of carbon fiber reinforced aluminum matrix composites with molybdenum carbide coating on carbon fibers

In this work, a molybdenum carbide coating on the surface of short carbon fibers prepared using molten salt method was proposed to ameliorate the interfacial bonding and improve the performance of carbon fiber/Al composites. The carbon fiber/Al composites were produced using vacuum hot pressing. The characteristics of molybdenum carbide coating were analyzed. Besides, the microstructures, bending strength and thermal properties of the carbon fiber/Al composites were explored. Furthermore, the interfacial thermal resistance of the composites was investigated in relation to theoretical evaluations derived from the combined Maxwell-Garnett effective medium approach and acoustic mismatch model schemes. The results indicated that a homogeneous Mo2C coating with a thickness of 0.5 μm was obtained by proper molar ratio of carbon fibers, MoO3 and chloride salts mixture and heated at 1000 °C for 60 min. The Mo2C coating greatly enhanced the bond between the aluminum matrix and carbon fiber, leading to improvements in the densification behavior and bending strength of the coated composites. The enhanced thermal properties including improved thermal conductivity and reduced coefficient of thermal expansion (CTE) were also achieved by the Mo2C coating. The in-plane thermal conductivity of 60 vol.% Mo2C-coated carbon fiber/Al composite was 221 W·m−1·K−1 enhanced by 92% compared to that of uncoated composite and the CTE was 6.0 × 10–6 K−1 which was suitable for electronic packaging materials.

In-situ constructing continuous networks composed of SiC nanowires for enhancing the thermal conductivity of epoxy composites

With the rapid miniaturization and high degree of integration of modern electronic devices, there is an increasing demand for high-performance polymer-based thermal management materials. SiC nanowires (SiCNWs) are very promising fillers benefiting from their large aspect ratio and ease of constructing thermally conductive networks. However, the traditional random mixing method allows the SiCNWs to form a thermally conductive network only through physical overlap, resulting in a high interfacial thermal resistance. To address this problem, an innovative strategy for in-situ generating continuous network composed of SiCNWs was proposed in this study, in which the SiCNWs was formed through impregnation-sintering process using an inexpensive polyurethane (PU) sponge as a template. The porous skeletons were sintered by numerous SiCNWs, which not only conferred more thermally conductive pathways, but also solved the problem of weak bonding at the SiCNWs random lap interface. On this basis, the SiC skeletons were further used as reinforcement to prepare epoxy (EP)-based composites. Benefiting from the continuous thermally conductive networks composed of SiCNWs, the composites achieved a thermal conductivity (TC) of ∼1.17 W m−1 K−1 at a low volume fraction of 21.18 vol%, which was 548.7 % higher than that of pure EP. In addition, the unique SiCNWs skeletons also facilitated the enhancement of mechanical properties and thermal stability of the composites, providing new insight for the preparation of innovative thermal management materials.

Dual role of two-dimensional graphene in silica aerogel composite: Thermal resistance and heat node

Incorporating two-dimensional graphene sheets, known for their high in-plane thermal conductivity, into silica aerogel enhances both the thermal insulation and mechanical properties of the composite. This work delves into the impact of graphene doping on the solid thermal conductivity of silica composites and their mechanical characteristics, employing molecular dynamics simulations that encompass both amorphous silica bulk and porous silica aerogel structures. Our findings reveal that graphene–silica interface thermal resistance notably restricts heat conduction in graphene doped silica aerogel, with the most pronounced effect occurring when graphene aligns vertically with the heat flux. Within porous silica aerogel, graphene serves as a “heat node”, bridging and connecting adjacent pores. A notable “trade-off” emerges: high weight percentages of graphene sheets augment heat transfer through the “heat node effect”, whereas the interfacial thermal resistance between graphene and aerogel reduces solid heat transfer, leading to decreased thermal conductivity. Additionally, while the inclusion of graphene sheets offers limited mechanical property enhancements, their two-dimensional structure can cause detachment and slipping from the silica matrix, leading to localized improvements in mechanical strength. This work sets the stage for advancing graphene-based aerogel composites characterized by low thermal conductivity and enhanced mechanical properties.

Effect of different titanium addition methods on the properties of diamond/Cu composites

Due to the low bonding strength between diamond and copper, the thermal conductivity and mechanical strength of diamond/copper composites are affected. In order to improve the interface bonding strength, this paper prepared diamond/Cu composites with titanium element in two forms: adding titanium to the copper matrix and using titanium coated diamond particles, respectively. The microstructure and composition analysis of the materials were carried out through SEM, EDS, AFM, etc. The bending strength and thermal conductivity of titanium coated diamond/copper composites reached 230 MPa and 480 W/(m·K), respectively, which were higher than the bending strength and thermal conductivity of diamond/Cu composites with added titanium in the matrix (208 MPa and 127 W/(m·K) and significantly higher than the corresponding properties of pure diamond/Cu composites (69 MPa and 108 W/(m·K)). Pre coating a layer of titanium carbide on the surface of diamond can serve as a connecting bridge, effectively reducing interfacial thermal resistance and improving mechanical properties, which is more effective than adding titanium powder to the matrix to improve the bending strength and thermal conductivity of diamond/Cu composites.

Constructing phonon transport bridges via low-temperature sintering in Diamond@Ag/EP composite to achieve efficient 3D networks structure

The rapid advancement of integrated circuits and electronic devices presents challenges to traditional epoxy molding compound (EMC), necessitating the demand for highly thermally conductive yet electrically insulating composites to address the “hotspot issues” in high-power chips. Here, a low-temperature sintering technology based on metal–organic decomposition is developed to fabricate a three-dimensional interconnected networks structure composite (3D-Diamond@Ag/EP). The in-situ decomposition of the silver amine complex on the surface of the Diamond@Ag hybrid filler forms nano-silver bridges, which facilitate the successful construction of the three-dimensional networks structure. When the Ag reaches 4.0 vol%, the thermal conductivity of the composite (reaches 6.42 W/m·K) breaks out of the low numerical blockade of the epoxy resin (0.18 W/m·K), while maintaining excellent insulation performance. It is noteworthy that the great improvement of thermal conductivity is achieved by the synergistic effect of sufficient thermal pathways and minimizing interfacial thermal resistance along these paths. Moreover, this work obtained composite exhibits other excellent thermal characteristics. It provided a practical route to produce high thermal conductivity polymer-based composites with electrical insulation for heat management in modern electronic devices.

An optimizing study of silicon-based microchannels for enhanced thermal transfer

The thermal transport efficiency of microchannel heat sinks is critically influenced by the solid-liquid interface thermal resistance, an aspect that has historically been underappreciated in the design of these systems. We introduce a hybrid model that combines molecular dynamics simulations with computational fluid dynamics to rigorously investigate the interfacial heat transfer characteristics of microchannels. Our methodology involves constructing a nanochannel composed of silicon atoms and water molecules to accurately measure the thermal resistance at the Si–H2O interface. We then extend our analysis by developing two-dimensional rectangular microchannel models. These models are utilized to examine the effects of thermal resistance, channel dimensions, and inlet velocity on the overall interfacial heat transfer rate. Our findings indicate a pronounced size dependency in the variation of the total heat transfer rate, highlighting the critical role of scale in these systems. Significantly, enhancements in heat transfer efficiency are observed with an increase in inlet velocity and a reduction in thermal resistance. These results underscore the importance of optimizing both physical and operational parameters to enhance the efficiency of microchannel heat sinks. The findings are expected to inform future designs and promote more efficient thermal management solutions in various applications.

Interfacial thermal resistance effect in self-aligned top-gate a-IGZO thin film transistors

This study investigates the interfacial thermal resistance effect, primarily associated with the bottom-gate stack, in self-aligned top-gate amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs). We analyze self-heating and heat transfer characteristics across three different a-IGZO TFT configurations: single-gate, dual-gate type 1, and dual-gate type 2. Temperature maps, corresponding to various bias conditions, are acquired using infrared thermal microscopy. The extracted values of thermal resistance reveal a significant disparity between single- and dual-gate configurations. This suggests that the bottom-gate stack in a-IGZO TFTs, including the interfaces, notably impedes heat dissipation. These findings offer crucial insights into the power dissipation aspects of TFT technology, highlighting the importance of interfacial design for thermal management in advanced electronic devices.

Enhanced thermal conductivity of PVDF by filling with T‐ZnOw and MWCNT based on hybrid 3D network

AbstractIn this work, a novel approach is taken to enhance the thermal conductivity and mechanical properties of composites by developing highly efficient thermally conductive PVDF‐based composites. This is developed by incorporating tetra‐pod zinc oxide whiskers (T‐ZnOw) in conjunction with multiwalled carbon nanotubes (MWCNT) to form binary hybrid fillers within a polyvinylidene fluoride (PVDF) matrix. Polydopamine (PDA), characterized by physical adsorption, is selected for surface coating on T‐ZnOw since T‐ZnOw is easy to self‐agglomerate and difficult to modify by physical and chemical methods. The coating aims to improve the dispersibility of T‐ZnOw and reduce the interfacial thermal resistance with the substrate. MWCNT is oxidized to improve its dispersion ability while strengthening the interaction with the matrix, due to the absence of interaction between MWCNTs and polymer matrix and poor dispersibility with the matrix. The dispersity of PDA@T‐ZnOw and o‐MWCNT is improved, and the three‐dimensional hybrid network structure can be better constructed to improve the thermal conductivity of the composite membrane. At a filler content of 25 wt%, the thermal conductivity reaches 0.302 W m−1 K−1 for T‐ZnOw–MWCNT–PVDF and 0.222 W m−1 K−1 for PDA@T‐ZnOw–o‐MWCNT–PVDF.

Interweaved filler network in epoxy resin with reduced interface thermal resistance via in-situ high-temperature “welding” for significantly improved thermal conductivity

For heterogeneous integration in harsh environments, polymeric materials are required to integrate excellent insulating property with significant thermal conductivity. Traditional discrete fillers used in polymeric matrix to create thermal pathways introduce numerous contact interfaces, leading to limited thermal conductivity enhancement efficiency (TCE) and unstable dielectric properties. Here, a distinctive strategy, involving the preparation of an interweaved thermally conductive filler with inherent heat channels through self-templated electrospinning and in-situ high-temperature “interface welding”, is proposed to reduce the interface thermal resistance (ITR). The growth of grains at high temperature facilitates the process of “interface welding”, while self-templated electrospinning establishes intrinsic thermal conduction pathways. Consequently, the epoxy resin fortified with this interweaved filler exhibits an exceptionally TCE of 162.15 % and enhanced in-plane thermal conductivity of 3.75 W m−1 K−1 at ultra-low filler ratio of 7.10 vol%. The combination of high electrical insulation of filler and low filler content results in excellent electrical insulating property (>1017 Ω cm) and stable dielectric properties over a frequency range of 103-106 Hz, enabling the successful implementation of heterogeneous integration in challenging environments. This work has the potential to offer a groundbreaking approach for achieving interconnected functional networks within polymer-based composites.

Thermal conductivity of composites with heterogeneous fillers under effects of interface thermal resistance

There has been significant interest in enhancing the effective thermal conductivity (ETC) of polymer by incorporating spherical hybrid fillers. However, the effect of interface thermal resistance (Rc) on the ETC of composites has not been investigated. In this paper, this effect is investigated. Meanwhile, the combined effects of filler thermal conductivities (K1, K2), filler sizes (V1, V2), the Rc sum (R*c1 + R*c2) and the Rc ratio (R*c1/R*c2) are also considered. The results show that for a given K1, K2 and R*c1 + R*c2, the ETC is largely independent of R*c1/R*c2 when the R*c1 + R*c2 is less than 10−4. However, when the R*c1/R*c2 ranges from 10−2 to 10, the competing effects of hybrid fillers Rc have a significant effect on the ETC. The ETC is not affected by the TC of filler-1 when K1 exceeds a critical value of 103, instead becoming dependent on K2. For each sum of Rc, there exists a critical value of R*c1/R*c2 where the ETC reaches its nadir, this critical value is influenced by the R*c1 + R*c2, V and K of two fillers. The Rc of fillers with high K is <10−2, it is not feasible to improve the ETC by continuing to reduce its Rc, this value is 10−4 for fillers with low K.

Nitrogen-doped bean-like SiC-based nanofibers for thermal insulation and electromagnetic wave absorption

SiC nanofibers that can be used to absorb electromagnetic wave (EMW) radiation and as thermal insulators simultaneously are highly desirable. In this work, nitrogen-doped bean-like SiC-based nanofibers were prepared by a simple electrospinning and high-temperature pyrolysis in a nitrogen atmosphere, focusing on studying the effects of nitrogen atom doping on the microstructure, EMW absorption, and thermal insulation properties of the fibers. The results showed that nitrogen doping promoted the formation of the SiOxCyNz phase in the fibers, which improved their interfacial thermal resistance and endowed the fibers with extremely low thermal conductivities (∼0.024 W·m−1·K−1 at 25 ℃, 0.092 W·m−1·K−1 at 1000 ℃). Furthermore, the density of carbon defects in the fibers was improved by nitrogen doping, which created numerous new polarization centers and effectively improved the dielectric loss. With a 4 mm thickness, a minimum reflection loss of −51.8 dB was exhibited at 6.3 GHz, indicating that these fibers are highly promising as an absorption material in harsh environments.

Multiphase Symbiotic Engineered Elastic Ceramic-Carbon Aerogels with Advanced Thermal Protection in Extreme Oxidative Environments.

Elastic aerogels can dissipate aerodynamic forces and thermal stresses by reversible slipping or deforming to avoid sudden failure caused by stress concentration, making them the most promising candidates for thermal protection in aerospace applications. However, existing elastic aerogels face difficulties achieving reliable protection above 1500°C in aerobic environments due to their poor thermomechanical stability and significantly increased thermal conductivity at elevated temperatures. Here, a multiphase sequence and multiscale structural engineering strategy is proposed to synthesize mullite-carbon hybrid nanofibrous aerogels. The heterogeneous symbiotic effect between components simultaneously inhibits ceramic crystalline coarsening and carbon thermal etching, thus ensuring the thermal stability of the nanofiber building blocks. Efficient load transfer and high interfacial thermal resistance at crystalline-amorphous phase boundaries on the microscopic scale, coupled with mesoscale lamellar cellular and locally closed-pore structures, achieve rapid stress dissipation and thermal energy attenuation in aerogels. This robust thermal protection material system is compatible with ultralight density (30mg cm-3), reversible compression strain of 60%, extraordinary thermomechanical stability (up to 1600°C in oxidative environments), and ultralow thermal conductivity (50.58mW m-1 K-1 at 300 °C), offering new options and possibilities to cope with the harsh operating environments faced by space exploration.