Amorphous SiO2 Research Articles

Highly crystalline Y3Al5O12:Ce3+ phosphor-in-silica glass ceramics for high-power solid-state lighting

The pursuit of high-brightness solid-state lighting (SSL) stimulates the development of all-inorganic color converters with high robustness. It is required that the fluorescent material is able to cope with the extreme condition generated from the irradiation of high-power-density excitation light. As such, in this work, we developed a new composite color converter, i.e., Y3Al5O12:Ce3+ phosphor-in-silica glass ceramic (YAG:Ce3+ PiSGC). Remarkably, the amorphous SiO2 matrix spontaneously transforms into tetragonal SiO2 crystallites during co-sintering with crystallization fraction reaching up to >90% (almost full ceramization). The activation energy for crystallization Ec and Avrami index n of amorphous silica oxide are 298.5 kJ/mol and 1.71, indicating the diffusion-controlled glass crystallization mechanism. The fabricated prototype high-power phosphor-converted white light-emitting diode (pc-wLED) and phosphor-converted white laser diode (pc-wLD) based on YAG:Ce3+ PiSGC show satisfactory photometric/colorimetric parameters. The developed color converters have combined merits of environmental protection property, cost-effective manufacturing, good luminescent performance, and easy scalability. This study highlights a new kind of opto-functional composite material and its application as an efficient color converter in high-power solid-state lightings.

Endothermic Dehydrogenation-Driven Preventive Magnesiation of Sio by Magnesium Hydride for High-Performance Sio-Based Lithium Storage Materials

Silicon monoxide (SiO)-based materials have gained much attention as high-capacity lithium storage materials because of their superior cycle performance. However, low initial Coulombic efficiency (ICE) of SiO derived from the irreversible electrochemical reaction of the amorphous SiO2 phase in SiO makes wide use of the SiO-based anode materials in lithium-ion batteries challenging. Magnesiation of SiO is one of the promising solutions to improve ICE of SiO-based anode materials. Here, we propose an endothermic dehydrogenation-driven magnesiation of SiO by employing MgH2 to improve both ICE and cycle performance. The resulting Si/Mg2SiO4 nanocomposite material showed much-improved ICE of 89.5% and long-term cycle performance for over 300 cycles compared to the homologue prepared by the magnesiation of SiO using Mg and pristine SiO. High-resolution transmission electron microscopy with thermogravimetry−differential scanning calorimetry revealed that the endothermic dehydrogenation of MgH2 mitigates the rapid temperature rise during magnesiation of SiO, thereby inhibiting the increase of Si domain size in the resulting Si/Mg2SiO4 nanocomposite. Detailed material characterization and electrochemical analysis of Si/Mg2SiO4 nanocomposite materials will be discussed in this presentation.

Corrosion behavior and mechanism of ytterbium silicates environmental barrier coatings subjected to thermal cycling in water vapor

AbstractYb2SiO5 and Yb2Si2O7 have been considered to be promising environmental barrier coatings (EBCs) materials for silicon‐based ceramics. Besides the various requirements EBCs must satisfy, it must be resistant to severe corrosion by high‐temperature water vapor as well as CMAS. In this work, the Yb2SiO5, Yb2Si2O7 coatings and Yb2SiO5/Yb2Si2O7/Si, Yb2SiO5/Si EBCs were subjected to steam with alumina at 1400°C for 200 h. Results showed that Yb3Al5O12 reaction layer and Yb2SiO5 corrosion layer were formed on the Yb2SiO5 coating, while porous Yb2SiO5 corrosion layer with Yb3Al5O12 phase was formed on the Yb2Si2O7 coating. By designing Yb2Si2O7 as intermediate layer, the corrosion resistance of Yb2SiO5/Yb2Si2O7/Si EBCs was significantly improved. In addition to phase transition of β‐cristobalite to α‐phase, crystallization of amorphous SiO2 also caused volume change, inducing longitudinal cracks through the TGO layer, which may lead to the failure of EBCs.

Study on Discharge Characteristics and Microstructural Evolution of PEO Coatings Based on an Al/Ti Tracer Substrate

In this study, samples underwent plasma electrolytic oxidation (PEO) treatment using Al/Ti tracer substrates for 5, 10, 20, 35, and 55 min. The ionization states were determined using Optical Emission Spectroscopy (OES). Microstructural and elemental analyses were conducted using scanning electron microscopy equipped with energy dispersive spectrometry (SEM-EDS). The structural organization and phase composition of the coatings were characterized using X-ray diffraction (XRD) and Raman spectroscopy, respectively. The research findings indicate that the early discharge stage is dominated by discharge within the pre-deposited Al layer, which undergoes gradual oxidation along the thickness direction, while Ti (0.25 wt%) is found on the coating surface. The power increase was 56% of the total increase from min 5 to min 10 of discharge. As discharge time increased, the spectral peaks corresponding to Ti gradually became stronger and were accompanied by gradual enhancement of the crystallinity of the anatase and rutile phases within the coating. The coating surface displayed closed and semi-closed pores in the middle of the discharge. After 55 min of discharge, amorphous SiO2 was observed and Ti content on the coating surface increased to 4.59 wt%.

Combined X-ray Reflectivity and Infrared Study of the Effect of Hydrogen Bonding of the OH Group on the Relaxation Behavior in Ultrathin Polyvinylphenol Films on SiO2.

Utilizing X-ray reflectivity and infrared reflection absorption spectroscopy (IR-RAS), we have investigated the thermal expansion and contraction of ultrathin polyvinylphenol (PVPh) films supported on a silicon (100) substrate capped with an amorphous SiO2 layer. Despite being known to form strong interactions with the SiO2 surface, the thin PVPh films showed a reduction in the glass-transition point Tg, similar to the behavior of polystyrene thin films deposited on SiO2. We explored the relationship between thermal expansivity and film thickness using well-annealed films and found that it decreases with film thickness in the range below twice the radius of gyration of a polymer chain (2Rg) in the glassy state. Thickness expansion in the glassy state and contraction in thickness at temperatures higher than Tg bulk (melt state) showed the presence of two competing relaxation processes. The reported negative thermal expansion in PVPh thin films, which was discovered to be one of the inherent properties, may have been caused by the fast relaxations that take place at the free polymer surface. IR-RAS was utilized to investigate the effect of thickness on hydrogen bonding in PVPh, and it was confirmed that with decreasing thickness, hydrogen bonding becomes weak, and the number of free OH groups increases. Therefore, thinner PVPh samples exhibit lower Tgs as an effect of easier molecular motions.

Synthesis and Characterization of Silicon–Carbon Powder and Its Resistance to Electron Irradiation

The issue of crystallization of silicon oxide at low temperatures is a topical issue for the electronics of the future. Organosilicon oligomers and polymers are “ideal” sources for obtaining ultrapure silicon ceramics and silicon nanoparticles. This paper presents the results of the synthesis of highly dispersed silicon-carbon powder from an organohydrosiloxane oligomer and the method for increasing its crystallinity at low temperatures. The diffraction pattern of the resulting powder corresponds to the amorphous–crystalline state of the components in this material, as evidenced by two intense and broadened amorphous halos in the region of Bragg angles 2θ = 7–11° and 18–25°. The resulting silicon–carbon powder was subjected to electron irradiation (E = 10 MeV; D = 106–107 Gy). This paper presents the data on the changes in powder properties via IR-Fourier spectroscopy, X-ray phase analysis, and scanning electron microscopy. Irradiation with fast electrons with an absorbed dose of 106 Gy leads to a slight crystallization of the amorphous SiO2 phase. An increase in the absorbed dose of fast electrons from D = 106 to D = 107 Gy leads to the opposite effect. An amorphization of silica is observed. This study showed the possibility of the crystallization of a silicon–carbon powder without a significant increase in temperature, acting only with electron irradiation. It is necessary to continue further research on expanding the boundaries of the optimal doses of absorbed radiation from fast electrons in order to achieve the maximum effect of the crystallization of silicon–carbon powder.

Reactivity of Group 5 and 6 Single-Site Photocatalysts for Partial Oxidation of Methane: Comparison of Chromium, Niobium, and Tungsten-Doped Mesoporous Amorphous Silica.

Single-site transition-metal-doped photocatalysts can potentially be used for partial oxidation of methane (POM) at remote sites where natural gas is extracted and methane is often flared or released to the atmosphere. While there have been several investigations into the performance of vanadium, there has been no general survey of the performance of other metals. This work aims and examines Cr, Nb, and W metal oxide materials embedded in amorphous SiO2 to determine the viability of each metal in catalyzing the POM. Photoexcited states are examined to determine the nature of the photoactivated species, and then the subsequent POM reaction mechanisms are elucidated. Using the calculated energies of reaction intermediates and transition states, the rate of methanol formation is evaluated through the use of a microkinetic model. The findings indicate that all three metals are potentially more suitable for catalyzing POM than vanadium but that niobium shows the most favorable energy profile.

Fabricating physicochemical microstructures with super hydrophilicity on Cf/SiC composites surface via picosecond-laser induced ablation

Cf/SiC composites are advanced high-temperature materials for thermal protection and high-performance braking systems in the aerospace industry. Their surface wettability significantly affects the adhesion properties of the coatings. This study investigated the physical and chemical transformations of Cf/SiC composites during picosecond laser ablation and successfully fabricated micro-structured surfaces with super-hydrophilicity. The findings revealed that three-scale microstructures were formed on Cf/SiC composites after picosecond laser-ablating, which were orderly composed of regular convex plates (20–60 μm), agglomerate ablative products (1–5 μm), and nano particles (100–500 nm). The relative content of O on the laser-ablating surface was mostly>25%, both Si–O and Si–C bonds were found on the Si2p peak of the XPS spectrum. The primary content of the ablative products was crystalline and amorphous SiO2, resulting from the oxidation of the SiC matrix. The initial surface of the Cf/SiC composites was hydrophobic, and its contact angle was 92.7°. Conversely, the laser-ablating surfaces showed significant absorption of water droplets owing to the presence of the hydroxyl group in the amorphous SiO2, and the droplets quickly disappeared from the surface through the micro “tubular channels” caused by carbon fibers sublimating and oxidizing under the high laser temperature. Consequently, the superhydrophilic surfaces of the Cf/SiC composites were obtained via picosecond laser ablation, and the motion of the droplets was closely related to the laser power and scanning distance.

Influence of copper calcium titanate nanoparticles designed with hierarchical interface structure on dielectric polarization and strength of polyvinylidene fluoride nanocomposites

Interface modification of nanofillers is an effective method to improve the dielectric property of the polymer composites constructed with different core–shell structured fillers. However, there are differences in the improvement and the dielectric response mechanisms are not clear. Herein, CaCu3Ti4O12 spherical nanoparticles (CCTO, marked as C), core–shell structured CCTO–SiO2 (CS), core–satellite structured CCTO–Ni (CN), and core–satellite–shell structured CCTO–Ni–SiO2 (CNS) nanoparticles are synthetized and used as fillers to investigate their effects on the dielectric polarization and strength of the PVDF–based nanocomposites. The results show that Ni nanoparticles are embedded within a 10 nm thick SiO2 shell and deposited on the surface of CCTO core with a diameter of 160 nm to form the hierarchical interface structured CNS fillers. Additionally, different interface structures of C, CS, CN, and CNS nanofillers play different roles in inducing interfacial polarization of the PVDF–based composites, which are weakened and enhanced by coating amorphous SiO2 shell and depositing Ni nanoparticles, respectively. Specially, the dielectric constant of the P–CN with a 1.5 vol% loading is 19.44 at 102 Hz, which is 69.8 % higher than that of PVDF. Significantly, the CNS fillers increase the dielectric constant and strength of the P-CNS composite to 15.05 and 147.2 kV/mm, respectively, and decrease leakage current density of 8.44 × 10−7 A/cm2, due to the hierarchical interfacial polarization effect of core–satellite–shell structured CNS and the restriction of the conductive path. This study provides more insight into the controlling of interface structure design on the dielectric polarization and strength, and offers a theoretical basis for designing polymer nanocomposites with high dielectric property.

Room temperature plasticity in amorphous SiO2 and amorphous Al[formula omitted]O[formula omitted]: A computational and topological study

Requirements for room temperature plasticity in oxides glasses have been only recently established. While atomistic mechanisms of this type of plasticity have been reported, it remains challenging to translate this knowledge between different structures and predict what other oxide glasses can be ductile and by which principle. Here we show that a coarse-grained analysis at the polyhedral level gives valuable information to accompany the atomistic characterization of plasticity, and we propose the analysis of polyhedral neighbor change events (PNCE) as a tool to allow comparison of the room temperature plasticity in various oxide glasses. Classical atomistic simulations with around 1 million atoms provided primitive data for coarse-grained analysis. Based on the PNCE analysis, the edge-sharing polyhedra are found to be up to 2 orders of magnitude more active in enabling plasticity, and combined with the occurrence of edge-sharing polyhedra, is shown to explain the brittle to ductile transition in a-SiO2 and the intrinsically high ductility of a-Al2O3. Finally, the coarse-grained analysis enables the benefit of using additional topological constraint theory analysis to yield more in-depth information regarding the ductile features of each glass structure. Quantitative comparison between amorphous Al2O3 and SiO2 shows a consistent trend between the materials and shows that the approach can be extended to the designing of other damage tolerant oxide glass materials.

Study of the Mineralogical Composition of an Alumina-Silica Binder System Formed by the Sol-Gel Method.

Colloidal bonds are realized by sol-gel technology. The binder system of the refractory castable belongs to the Al2O3-SiO2 binary diagram. Mullite is the most thermally stable mineral in this system. This work was motivated by an attempt to maximize the mullite content in the NCC binder system, because a high content of mullite is a guarantee of the long service life of refractories. Initially, the mineralogical composition of the pure gel was tested after drying and firing at temperatures between 1000 °C and 1600 °C. The behavior of the gel during drying was described. Subsequently, a method of minimizing gel shrinkage during drying was sought. To this aim, fine fillers (microfillers) of alumina and silica were tested. In particular, the reactivity of the microfillers, the ability of the microfillers to react with the sol to form mullite, and the drying shrinkage of the microfiller-doped gel were evaluated. The study showed that the least suitable source of Al2O3 in terms of its reactivity is tabular corundum, which produces the lowest amount of mullite. The internal structure of the prepared binder system when using different microfillers was described. Based on the results from the second stage of the work, several complete matrixes of the binder system were designed and the degree of their mullitization at different firing temperatures was studied. During this stage, it was shown that the degree of mullitization of the binder system depends mainly on the microsilica content. In the binder system, the maximum mullite content recorded was 76%. The effect of amorphous SiO2 on the bulk density and internal structure of the binder system was also described.

Composition and structural identification of silicon particles in diamond wire saw silicon powder

In this study, the content and calculation equations of each substance in diamond wire saw silicon powder (DWSSP) were determined. Initially, the presence of amorphous SiO2 was proven by crystal transformation. Then, the SiO2 content was determined by SiO2-CaO phase diagram analysis, and the SiO x content was determined by using the oxygen conservation rule. The variation trend between the SiO2, SiO x , and Si contents and the O content was determined, according to the calculated SiO2 and SiO x content. In addition, linear fitting was performed on the SiO2, SiO x , and Si contents of five DWSSP raw materials, and a calculation equation for SiO2, SiO x , and Si was obtained through the total O content. The three-layer structure of DWSSP was revealed, the DWSSP consisting of a Si core, an intermediate SiO x layer, and a SiO2 shell. This study can accurately identify the content of SiO2, SiO x , and Si in DWSSP based on the detected oxygen content, and provide a better theoretical basis for the process selection and design for silicon recovery or high value materials preparation.

Amorphous SiO2 Surface Irregularities and their Influence on Liquid Molecule Adsorption by Molecular Dynamics Analysis

As the semiconductor industry relentlessly reduces device sizes, efficient and precise cleaning processes have become increasingly critical to address challenges such as nanostructure stiction. Gaining insight into the molecular behavior of water and isopropyl alcohol (IPA) on silicon dioxide (SiO2) surfaces is essential for controlling semiconductor wet cleaning processes. This study investigated the interactions between these liquids and SiO2 surfaces. Using molecular dynamics (MD) simulations, we examined the adsorption behavior of water and IPA molecules on both amorphous and crystalline SiO2 (a-SiO2 and c-SiO2) surfaces. Our findings reveal a preferential adsorption of water molecules on a-SiO2 surfaces compared to c-SiO2. This preference can be ascribed to the irregularity of the a-SiO2 surface, which results in the presence of silanol groups that remain inaccessible to the liquid molecules. In contrast, the c-SiO2 surface exhibits a more uniform and accessible structure. This study not only imparts crucial insights into the molecular behavior of water and IPA on SiO2 surfaces but also provides valuable information for future enhancements and optimization of semiconductor wet surface preparation, cleaning, etching and drying.

Lower hardness than strength: The auxetic composite microstructure of limpet tooth.

The limpet tooth is widely recognized as nature's strongest material, with reported strength values up to 6.5 GPa. Recently, microscale auxeticity has been discovered in the leading part of the tooth, providing a possible explanation for this extreme strength. Utilizing micromechanical experiments, we find hardness values in nanoindentation that are lower than the respective strength observed in micropillar compression tests. Using micromechanical modeling, we show that this unique behavior is a result of local tensile strains during indentation, originating from the microscale auxeticity. As the limpet tooth lacks ductility, these tensile strains lead to microdamage in the auxetic regions of the microstructure. Consequently, indentation with a sharp indenter always probes a damaged version of the material, explaining the lower hardness and modulus values gained from nanoindentation. Micropillar tests were found to be mostly insensitive to such microdamage due to the lower applied strain and are therefore the suggested method for characterizing auxetic nanocomposites. STATEMENT OF SIGNIFICANCE: This work explores the micromechanical properties of limpet teeth, nature's strongest biomaterial, using micropillar compression testing and nanoindentation. The limpet tooth microstructure consists of ceramic nanorods embedded in a matrix of amorphous SiO2 and arranged in a pattern that leads to local auxetic behavior. We report lower values for nanoindentation hardness than for compressive strength, a unique behavior usually not achievable in conventional materials. Utilizing micromechanical finite element simulations, we identify the reason for this behavior to be microdamage formation resultant of the auxetic behavior, sharp indenter tip and lack of ductility of the limpet tooth microstructure. This formation of microdamage is not expected in micropillar compression tests due to lower locally imposed strain.

Preparation of glass-ceramic-based artificial aggregates using multiple solid wastes: Crystallization mechanism

In this study, the effects of two types of waste glasses on the performance of glass-ceramic artificial aggregates (AAs) were investigated to determine the contribution of the glass in the crystallization processes and provide theoretical support for the subsequent use of the solid wastes to prepare glass-ceramic-based AAs. The results showed that introducing glass mainly provided amorphous materials to facilitate crystallization and fluxing components to reduce liquid viscosity. The crystallization mechanism of the AAs was explained by understanding the SiO2 characteristics and the liquid viscosity on the AAs properties. The results showed that amorphous SiO2 and low viscosity were beneficial to the crystallization process, and the properties of [Si–O] significantly influenced the viscosity of the liquid phase. AAs prepared with multiple solid wastes were compared with pure muck AAs, and they showed higher strength with similar densities.

Ultrathin Polymer Fibers Coated with an Amorphous SiO2–CaO–P2O5 Bioactive Powders for Biomedical Applications

Ultrathin Polymer Fibers Coated with an Amorphous SiO2–CaO–P2O5 Bioactive Powders for Biomedical Applications

Highly Selective Transformation of CO2 + H2 into Para-Xylene via a Bifunctional Catalyst Composed of Cr2O3 and Twin-Structured ZSM-5 Zeolite

The abundant C1 source CO2 can be utilized to produce value-added chemicals through hydrogenation technology. A bifunctional catalyst consisting of reducible metal oxide Cr2O3 and acidic zeolite ZSM-5 was designed for the direct conversion of CO2 + H2 into valuable aromatics, especially para-xylene (PX), via the methanol-mediated pathway. The twin structure of ZSM-5 (ZSM-5T), with sinusoidal channels that are predominantly exposed to the external surface, enhances the possibility of the transformation of methanol into PX due to the favorable diffusion dynamic of PX in the sinusoidal channels. Via the bifunctional catalyst Cr2O3&ZSM-5T, a PX selectivity of 28.7% and PX space-time yield (STY) of 2.5 gCH2 h−1 kgcat−1 are achieved at a CO2 conversion rate of 16.5%. Furthermore, we rationally modify the ZSM-5T zeolite via Cu species doping and amorphous SiO2 shell coating (Cu-ZSM-5T@SiO2). After combining with the Cr2O3 catalytic component, the CO2 conversion (18.4%) and PX selectivity (33.8%) are increased to some extent, which systematically increases the STY of PX to 3.0 gCH2 h−1 kgcat−1. The physicochemical property of the acidic zeolite and the corresponding structure-function relationship in enhancing the PX productivity are discovered. Our work provides a novel catalyst design idea to boost PX synthesis performance from CO2 hydrogenation.

Interfacial reaction in Al2O3 fiber reinforced TiAl matrix composite

Al2O3 short fiber (containing 28 vol.% SiO2) reinforced TiAl matrix composite was prepared by spark plasma sintering (SPS). The interfacial reaction mechanism was clarified by thermodynamic and kinetic analyses. The main interfacial phase was Ti5Si3, originated from Ti element of TiAl matrix and Si element of Al2O3 fiber. The activation energy of interfacial layer was 285.1 kJ/mol. In addition, the matrix around the interfacial region was composed of γ-TiAl phase due to the consumption of Ti element in the process of interfacial reaction. However, the formation of mullite phase occurred in the heat-treated Al2O3 fiber and as-sintered composite due to the chemical reaction between γ-Al2O3 and amorphous SiO2 phases.

Oxide layer coating enabling oxysulfide-based photocatalyst sheet to drive Z-scheme water splitting at atmospheric pressure

•Photocatalyst sheets made of La5Ti2Cu0.9Ag0.1O7S5 (LTCA) and BiVO4 split water •Backward reactions on LTCA suppress the STH at elevated pressure •SiO2 coating allows the photocatalyst sheet to maintain an STH of 0.41% at 90 kPa •Pathways to activate photocatalyst sheets under realistic conditions are identified A photocatalyst sheet consisting of doped La5Ti2Cu0.9Ag0.1O7S5 as a hydrogen evolution photocatalyst (HEP), BiVO4 as an oxygen evolution photocatalyst (OEP), and Au as a conductor layer exhibits a solar-to-hydrogen energy conversion efficiency (STH) of 0.67% at 4 kPa in Z-scheme overall water splitting (ZOWS). However, the photocatalyst sheet loses its activity at elevated pressure due to backward reactions. Here, we show that this loss of activity can be suppressed by coating the sheet with amorphous SiO2 layer. In addition, the SiO2 coating maintained its performance at elevated temperatures, unlike the widely used amorphous TiO2 coating, and exhibited an STH of 0.41% at 90 kPa and 333 K. The results of the present study demonstrate the ability to functionalize photocatalyst sheets of narrow-band-gap materials prone to backward reactions, allowing their use in outdoor environments, and paves the way for practical solar hydrogen production. A photocatalyst sheet consisting of doped La5Ti2Cu0.9Ag0.1O7S5 as a hydrogen evolution photocatalyst (HEP), BiVO4 as an oxygen evolution photocatalyst (OEP), and Au as a conductor layer exhibits a solar-to-hydrogen energy conversion efficiency (STH) of 0.67% at 4 kPa in Z-scheme overall water splitting (ZOWS). However, the photocatalyst sheet loses its activity at elevated pressure due to backward reactions. Here, we show that this loss of activity can be suppressed by coating the sheet with amorphous SiO2 layer. In addition, the SiO2 coating maintained its performance at elevated temperatures, unlike the widely used amorphous TiO2 coating, and exhibited an STH of 0.41% at 90 kPa and 333 K. The results of the present study demonstrate the ability to functionalize photocatalyst sheets of narrow-band-gap materials prone to backward reactions, allowing their use in outdoor environments, and paves the way for practical solar hydrogen production.

Flexible TiO2/SiO2 nanofibrous membrane with high near-infrared reflectance for thermal insulation

In this study, we successfully fabricated TiO2/SiO2 ceramic nanofibrous membranes with different molar ratios using a combination of electrospinning and sol-gel technology. The resulting nanofibers were composed of amorphous SiO2 and fine-grained anatase; the amorphous SiO2 served as a lubricating zone and refined the rutile grains in the nanofiber structure. The hybrid nanofibrous membranes exhibited exceptional mechanical properties: the highest average tensile strength was 3.22 ± 0.98 MPa, which is threefold higher than that of the TiO2 nanofibrous membranes. Consequently, the TiO2/SiO2 nanofibrous membranes withstood stretching, bending, folding, and compressing processes without breaking. Furthermore, the average reflectance of the TiO2/SiO2 nanofibrous membranes exceeded 89.57% in the range of 500–2500 nm, and their thermal conductivity at room temperature was below 0.0310 W·m − 1K−1. The flexible and robust ceramic materials have significant potential for various applications such as thermal insulation, flexible energy, and wearable electronics.