High Thermal Stability Research Articles

Structure development and photoluminescence properties of high-purity greenish-yellow emitting LaGaO3:Dy3+ phosphors

This study investigates the structure development and photoluminescence properties of high-purity greenish-yellow emitting LaGaO3 phosphors doped with dysprosium ions Dy3+. The phosphors were synthesized using a high-temperature solid-state reaction method. X-ray diffraction (XRD) confirmed the formation of a single-phase LaGaO3:Dy3+ structure and scanning electron microscopy (SEM) revealed uniform particle size and morphology. The phosphor exhibits the capability of being efficiently excited by ultraviolet 350 nm exhibiting the characteristic greenish-yellow emission with two strong peaks at 478 nm (cyan) and 572 nm (yellow), ascribing to the transitions of 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2, respectively. The electronic transition mechanism is direct exchange interaction between activators, contributing to the concentration quenching. The phosphor was able to retain 67 % of its intensity without significant color change at an elevated temperature up to 25 °C to 150 °C. The CIE chromaticity coordinates of the emitted light were calculated and found in the desired greenish-yellow region. The electroluminescence performance of the LaGaO3:0.06Dy3+ phosphor was investigated using 365 nm LED chips to check their applicability in the field of white light-emitting diodes (WLEDs). The synthesized phosphors demonstrated high thermal stability, making them suitable for white-LED applications. The study highlights the potential of LaGaO3:Dy3+ phosphors in enhancing white-LEDs' color quality and efficiency.

Catalytic Strategies Enabled Rapid Formation of Homogeneous and Mechanically Robust Inorganic‐Rich Cathode Electrolyte Interface for High‐Rate and High‐Stability Lithium‐Ion Batteries

AbstractLithium iron phosphate (LFP) cathode is renowned for high thermal stability and safety, making them a popular choice for lithium‐ion batteries. Nevertheless, on one hand, the fast charge/discharge capability is fundamentally constrained by low electrical conductivity and anisotropic nature of sluggish lithium ion (Li+) diffusion. On the other hand, the interface and internal structural degradation occurs when subjected to high‐rate condition. Herein, a multifunctional boron‐doping graphene/lithium carbonate (BG/LCO) nanointerfacial layer on surface of commercial LiFePO4 particles is designed, in which the BG layer catalyzes the rapid reaction of Li2CO3‐LiPF6 for homogeneous and mechanically robust inorganic LiF‐rich structure across the cathode‐electrolyte interphase (CEI), forms a conductive network to significantly enhance both electron and Li+ transport, and strengthens the FeO bonding to minimize both Fe loss and the formation of Fe‐Li antisite defects. Correspondingly, the modified LFP cathode achieves a high capability of 113.2 mAh g−1 at 10 C and extraordinary cyclic stability with 88.0% capacity retention over 1000 cycles as compared to the pristine LFP cathode with a capacity of only 94.0 mAh g−1 and 64.6% capacity retention. It also exhibits great enhancements of 20.1% and 3.7% at higher‐rate condition (room temperature/15 C) and the low temperature condition (−10 °C/1 C), respectively.

A preliminary investigation of banana pseudo-stem (Musa cavendish) for pulp and paper production: morphology, chemical composition, FTIR, XRD and thermogravimetric analysis

Abstract In today’s world, the use of paper and cardboard increasing but the availability of raw materials and the environmental impact on the paper industry is a big concern. To address these concerns, researchers are exploring the potential of agricultural waste products as raw materials for pulp production. This study uses morphological, chemical composition, FTIR, XRD, and thermogravimetric analysis to examine the potential of banana pseudo-stem as a raw material for paper pulp to address environmental concerns and raw material shortages in the paper industry. The study reveals favorable characteristics for papermaking, including long fiber length (1750 μm), thin cell wall thickness (9.7 μm), and large lumen diameter (22.15 μm). The chemical composition of banana pseudo-stem contains cellulose (44.93 %), hemicellulose (23.7 %), and Klason lignin (11.1) showing its suitability for pulp production. FTIR analysis highlights the functional groups present on the banana pseudo-stem. The XRD analysis shows that it has a similar cellulosic peak and crystallinity index with common raw materials used in pulp production. The thermogravimetric analysis shows that the banana pseudo-stem has high thermal stability. The findings demonstrate that banana pseudo-stem, both by itself and in combination with other raw materials, might be a potential raw material for the pulp production.

Infiltration of glass nanofiber-reinforced polylactic acid into delignified hardwood toward photoluminescent and mechanically reliable smart windows

Ultraviolet-protective, mechanically reliable, and photoresponsive wood that can switch color under ultraviolet light was developed. A combination of alkaline earth-doped strontium aluminate (ASA) as a photoluminescent pigment and glass nanofiber-supported polylactic acid as a hosting agent was infused into a delignified wood, producing transparent wood with photochromic activity. The ASA phosphor has proven high thermal stability and photostability. A typical process for producing colorless photoluminescent wood includes the well-dispersion of ASA in glass nanofiber-supported polylactic acid without agglomeration. As proven by the coloration measurements, the current photoluminescent wood becomes green under ultraviolet light and remains transparent under daylight. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) were employed to determine the morphology of the phosphor particles and glass fibers, demonstrating sizes of 12–21 nm and 50–125 nm, respectively. The luminescent wooden samples were studied by numerous microscopic and spectroscopic techniques, including SEM, X-ray fluorescence (XRF), and energy-dispersive X-ray (EDX). Upon excitation at 365 nm, the luminescence wood demonstrated an emission peak at 518 nm. When increasing the ASA concentration, the photoluminescent hardwoods displayed improved ultraviolet protection and better water resistance. The responsiveness of the luminescent wood to UV irradiation was fast and reversible.

Ultrathin PVP/ZnMoO4@PE separator for high-safety sodium-ion batteries

In this work, an ultrathin (∼19 μm) PVP/ZnMoO4@PE separator is designed and achieved with much enhanced thermal performance for high-safety sodium-ion batteries (SIBs). The PVP/ZnMoO4@PE separator is prepared by coating the polyvinyl pyrrolidone (PVP)/ZnMoO4 ceramic slurry on one side of commercial polyethylene (PE) separator in an economically efficient way. It is found that the superior PVP binder would interact with ZnMoO4 nanoparticles and enhance the bonding strength of heat-resistant ZnMoO4 ceramic nanoparticles on the surface of PE substrate, which significantly improves the thermal performance of the optimized separator. The optimized PVP/ZnMoO4@PE separator shows high thermal stability with no shrinkage at 180 °C for 30 min. In addition, the PVP/ZnMoO4@PE separator shows improved wettability with electrolyte, larger porosity and better electrolyte storage capacity than bare PE separator, which are quite beneficial to ionic conductivity. Furthermore, the electrochemical results show that half-cell (hard carbon/sodium) assembled with the optimized PVP/ZnMoO4@PE separator shows better electrochemical performance that the half-cell assembled with commercial glass fiber separator (thickness of ∼ 455 μm), while bare PE separator does not work properly in SIBs. This study provides insight into the practical application of ultrathin and high-safety PVP/ZnMoO4@PE separator in commercial SIBs.

Exfoliated Porous Carbon Nitride by Simultaneous Oxidation-Corrosion for Photocatalytic H2O2 Production and Organic Degradation.

Graphitic carbon nitride (g-C3N4) is a fascinating material with potential applications in photocatalysis due to its good chemical stability, high thermal stability, and relative ease of synthesis. In this work, ultrathin g-C3N4 is constructed using a hybridized method, which combines the advantages of thermal and liquid-phase stripping methods. This sample can improve performance in degrading organic pollutants several times, and the highest enhancement efficiency occurs in an alkaline environment. In addition, photocatalytic production of hydrogen peroxide can be increased to 2.6 times that of the bulk sample. These improved properties are due to the increase in specific surface area, the generation of free radicals, and adsorption capacity. This work presents a one-step exfoliation method for bulk g-C3N4 for more surface-active sites and strong redox capacity.

Enhancing adsorbent performance for direct air capture of CO2 by in-situ amine-grafting of layered double hydroxides

The development of efficient and cost-effective CO2 adsorbents is crucial for carbon capture from ultradilute conditions. Amine-grafted mesoporous materials prepared by silane chemical reactions are well-known CO2 adsorbents with high thermal stabilities, but their capacities for direct air capture (DAC) are usually restricted by low amine loadings and CO2 capture capacity. Herein, we present an in-situ amine grafting method that enables high amine loadings by in-situ grafting initial ultrathin LDHs nanosheets in an organic solvent. For in-situ triamine grafted Mg2Al-CO3 LDH (IN-TRI-LDH) amine loading is boosted to 5.91mmol N g−1 and ultimately achieving a remarkable adsorption capacity of 0.98 mmol g−1 at 25°C and 400 ppm CO2, nearly double that of the amine-LDHs grafted through a conventional two-step process. A further 22 % enhancement of the CO2 capacity is observed under 20 RH%. In addition, IN-TRI-LDH maintains a working capacity of 0.85 mmol g−1 at a low desorption temperature of 70 °C. A 50 adsorption–desorption cyclic test under simulated humid DAC conditions shows minimal performance degradation. Such a sufficient working capacity and low desorption temperature reduces the thermal energy consumption to 2.27 GJ t−1 at a desorption temperature of 40 °C.

Covalent Lysozyme Immobilization on Enzymatic Cellulose Nanocrystals.

Nanostructured materials represent promising substrates for biocatalyst immobilization and activation. Cellulose nanocrystals (CNCs), accessible from waste and/or renewable sources, are sustainable and biodegradable, show high specific surface area for anchoring a high number of enzymatic units, and high thermal and mechanical stability. In this work, we present a holistic enzyme-based approach to functional antibacterial materials by bioconjugation between the lysozyme from chicken egg white and enzymatic cellulose nanocrystals. The neutral CNCs were prepared by endoglucanase hydrolysis from Avicel. We explore the covalent immobilization of lysozyme on enzymatic CNCs and on their TEMPO oxidized derivatives (TO-CNCs), comparing immobilization yields, material properties, and enzymatic activities. The materials were characterized by X-ray diffractometry (XRD), attenuated total reflectance Fourier Transform infrared spectroscopy (ATR-FTIR), bicinchoninic acid (BCA) assay, field-emission scanning electron microscopy (FE-SEM) and dynamic light scattering (DLS). We demonstrate the higher overall efficiency of the immobilization process carried out on TO-CNCs, based on the success of covalent bonding and on the stability of the isolated bioconjugates.

Synergistic effects of multi-walled carbon nanotubes and Mn0.4Cu0.6Fe2O4 on mercury removal with high efficiency and sulfur resistance

Although ferrite-based adsorbents are the potential mercury removal materials for the high thermal stability, they usually suffer from a low efficiency in flue gas environment, especially under SO2 condition. In the present paper, the multi-walled carbon nanotubes (MWCNTs) are utilized to improve the adsorption capacity of the Mn0.4Cu0.6Fe2O4 adsorbents as well as inhibit the influence of flue gas composition. The influences of temperature, adsorbent type and the flue gas composition on Hg0 removal efficiency are evaluated by experiments. The physical adsorption property of MWCNTs provides a platform for Hg0 oxidation by Mn0.4Cu0.6Fe2O4. The synergistic effect between MWCNTs and Mn0.4Cu0.6Fe2O4 enhances the mercury removal efficiency as well we the sulfur resistance. The results find that the adsorbent of Mn0.4Cu0.6Fe2O4 containing 14 % MWCNTs has a high mercury removal efficiency of 95.6 % at 120 °C even under 1000 ppm SO2 concentration. The kinetic behaviors of adsorbent adsorption are analyzed by theoretical models. The mechanisms of porous carbon-containing modifier to improve the mercury removal performance of Mn0.4Cu0.6Fe2O4 are explored carefully. The present ferrite-based adsorbent exhibits promising prospects for the practical industrial applications of the low temperature mercury removal from coal-fired flue gas.

Metal‐Free, Light‐Catalyzed ATRP For the Synthesis of Functional PVDF‐Based Block Copolymers and Their Characterization

AbstractThe synthesis and characterization of poly(vinylidene fluoride) (PVDF)‐based block copolymers using a metal‐free light‐catalyzed atom transfer radical polymerization (ATRP) approach are described. A PVDF macroinitiator with C─Br bonds at both ends of the chain is synthesized, and an organic photoredox catalyst (OPRC) is used to control the process. The metal‐free process expands the possibilities for the synthesis and application of PVDF‐based block copolymers, as it allows the use of monomers that is previously incompatible with classical ATRP due to their interaction with metal catalysts. The synthesized block copolymers are characterized structurally and thermally as powder materials and in thin films. Fourier‐transform infrared spectroscopy (FT‐IR) analysis revealed that the crystalline phase of PVDF changes when thin films are formed. Specifically, the disappearance of the FT‐IR peaks related to the gamma phase and the presence of characteristic peaks related to the alpha and beta phases indicate that film formation rearranged the PVDF chains, leading to changes in their crystalline phases. These PVDF‐based block copolymers have unique properties, including high thermal stability, chemical resistance, and piezoelectricity, making them potential candidates for use in various fields, such as biomedical engineering, energy storage, and electronic devices.

Enhanced performance of low-dielectric siloxane-polyimide copolymers: Synthesis and properties

Low-dielectric polyimides (PI) films with outstanding overall performance are attractive for next generation microelectronic applications. Herein, a series of two different FPIs and BPIs derived from 4,4′-diaminodiphenyl ether (ODA) and two different functional dianhydrides, 4,4'-(hexafluoroisopropylidene) biphthalic anhydride (6FDA) and 4,4′-(4,4′-isopropyldiphenoxy) biphthalic anhydride (BPADA), respectively, were synthesized by a conventional two-step methodology that included thermoimidatization. Additionally, employing aminopropyl-terminated polydimethylsiloxane PDMS (molecular weight = 1000) as the source of siloxane-oxygen bonds, a series of polyimide siloxane (SiFPIs and SiBPIs) copolymers were synthesized by varying the siloxane content (ranging from 0 to 5 wt%) within the copolymer structure. The effects of siloxane bond on the thermal, solubility, water resistance, dielectric and mechanical properties of polyimide were investigated systematically. The integration of siloxane significantly enhanced the solubility of these copolymers in polar aprotic solvents (DMAC, DMF, NMP), expanding their applicability in diverse processing environments. Crucially, these copolymers exhibited remarkably low dielectric constants—2.90 for SiFPI at 3% PDMS and 2.92 for SiBPI at 4% PDMS—coupled with low loss values, positioning them as prime candidates for advanced microelectronic applications. All the composite films have high thermal stability near pure PI. The introduction of PMDS into PI can improve the elongation at break and at the same time, the composite films still remained with higher modulus and tensile strength. Extensive hydrophobicity assessments through contact angle and water absorption studies underscored the copolymers’ superior moisture resistance, a critical parameter for their potential deployment in high-performance, environmentally sensitive electronic components.

Molecular dynamics simulations of uranyl and plutonyl cations in a task-specific ionic liquid.

Ionic liquids (ILs) are a unique class of solvents with potential applications in advanced separation technologies relevant to the nuclear industry. ILs are salts with low melting points and a wide range of tunable physical properties, such as viscosity, hydrophobiciy, conductivity, and liquidus range. ILs have negligible vapor pressure, are often non-flammable, and can have high thermal stability and a wide electrochemical window, making them attractive for use in separations processes relevant to the nuclear industry. Metal salts generally have a low solubility in ILs; however, by incorporating new functional groups into the IL cation or anion that promote complexation with the metal, the solubility can be greatly increased. One such task-specific ionic liquid (TSIL) is 1-carboxy-N, N, N-trimethylglycine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) [Nockemann et al., J. Phys. Chem. B 110, 20978-20992 (2006)]. Water, which is detrimental for electrochemical separations, is a common impurity in ILs and can coordinate with actinyl cations, particularly in ILs containing only weakly coordinating components. Understanding the behavior of actinides in TSIL/water mixtures on a molecular level is vital for designing improved separations processes. Classical molecular dynamics simulations of uranyl(VI) and plutonyl(VI) in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf2N]) with deprotonated Hbet (betaine) and water have been performed to understand the coordination and dynamics of the actinyl cations. We find that betaine is a much stronger ligand than water and prefers to coordinate the metal in a bidentate manner. Potential of mean force simulations yield a relative free energy for betaine coordination of approximately -120 to -90 kJ/mol in mixtures with water. As the amount of betaine coordinated to the actinide increases, the diffusion coefficient of the actinyl cation decreases. Moreover, the betaine ligand is able to bridge between two metal centers, resulting in dimeric complexes with actinide-actinide distances of ∼5Å. Potential of mean force simulations show that these structures are stable, with relative free energies of up to -40 kJ/mol. The crystal structure for [(UO2)2(bet)6(H2O)2][Tf2N]4 shows that the betaine bridges between two uranium atoms to form dimeric complexes similar to those found in our simulations [Nockemann et al. Inorg. Chem. 49, 3351-33601 (2010)].

9-(9-Alkylcarbazol-3-yl)-3-(methoxypyridin-3-yl)carbazoles as host materials for very efficient OLEDs

Four derivatives of 9-(9-alkylcarbazol-3-yl)-3-(methoxypyridin-3-yl)carbazoles (HM1-HM4) have been synthesized from key starting compounds: 9-alkyl-3-iodocarbazoles and corresponding 3-(methoxypyridin-3-yl)-9H-carbazoles by using Ullmann coupling reactions. The objective materials have very high thermal stabilities (temperatures of 5 % weight loss 371–387 °C) and can form amorphous layers, also having rather high glass transition temperatures in the region of 89–97 °C. Triplet energy gaps of the four compounds were about 2.7–2.8 eV, making them appropriate for use as host materials in green phosphorescent OLEDs with Ir(ppy)3 guest. Additionally, a composite host system incorporating a synthesized compound of HM series and bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine was developed. The devices with HM2 or HM4 demonstrated the best characteristics whether the emitting layer was a single host or a co-host system, indicating that both compounds could facilitate ideal energy transfer and achieve carrier balance in the device architectures. Notably, the device using 9-(9-butylcarbazol-3-yl)-3-(2-methoxypyridin-3-yl)carbazole (HM2) host outperformed the other devices, achieving peak efficiencies of 16.9 % (58.3 cd/A and 65.0 lm/W) with maximum luminance exceeding 241100 cd/m2.

Structural dynamics of the Ca2+-regulated cutinase towards structure-based improvement of PET degradation activity

We previously revealed the structural basis of Ca2+ dependent regulation of a polyethylene terephthalate (PET)-degrading enzyme, Cut190, and proposed a unique reaction cycle in which the enzyme repeatedly binds and releases Ca2+. Here, we report crystal structures of Cut190 mutants with high thermal stability complexed with PET-like ligands that contain aromatic rings. The structural information has allowed us to perform further computational analyses using a PET-trimer bound model. Our multicanonical molecular dynamics simulations and subsequent analyses of the free energy landscapes revealed a novel intermediate form that occurs during the enzymatic reaction cycle. Furthermore, the computational analyses were used to investigate the effect of the point mutations F77L and F81L in the Ca2+-binding site, which showed that the former stabilizes the engaged and open forms to improve transition between the open and active forms, while the latter extremely increases the open form. Subsequent experiments showed that the F77L mutation increased the activity, while the F81L mutation decreased the activity. Our computational analysis has enabled us to explore the dynamics of Cut190 on a completely new level, providing key insights into how the balance between the various conformations influences the reaction cycle and ultimately how to improve the reaction cycle.

Temperature-responsive solvation enabled by dipole-dipole interactions towards wide-temperature sodium-ion batteries

Rechargeable batteries with high durability over wide temperature is needed in aerospace and submarine fields. Unfortunately, Current battery technologies suffer from limited operating temperatures due to the rapid performance decay at extreme temperatures. A major challenge for wide-temperature electrolyte design lies in restricting the parasitic reactions at elevated temperatures while improving the reaction kinetics at low temperatures. Here, we demonstrate a temperature-adaptive electrolyte design by regulating the dipole-dipole interactions at various temperatures to simultaneously address the issues at both elevated and subzero temperatures. This approach prevents electrolyte degradation while endowing it with the ability to undergo adaptive changes as temperature varies. Such electrolyte favors to form solvation structure with high thermal stability with rising temperatures and transits to one that prevents salt precipitation at lower temperatures. This ensures stably within a wide temperature range of ‒60 −55 °C. This temperature-adaptive electrolyte opens an avenue for wide-temperature electrolyte design, highlighting the significance of dipole-dipole interactions in regulating solvation structures.

Efficient Removal of PFASs Using Photocatalysis, Membrane Separation and Photocatalytic Membrane Reactors.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are persistent compounds characterized by stable C-F bonds giving them high thermal and chemical stability. Numerous studies have highlighted the presence of PFASs in the environment, surface waters and animals and humans. Exposure to these chemicals has been found to cause various health effects and has necessitated the need to develop methods to remove them from the environment. To date, the use of photocatalytic degradation and membrane separation to remove PFASs from water has been widely studied; however, these methods have drawbacks hindering them from being applied at full scale, including the recovery of the photocatalyst, uneven light distribution and membrane fouling. Therefore, to overcome some of these challenges, there has been research involving the coupling of photocatalysis and membrane separation to form photocatalytic membrane reactors which facilitate in the recovery of the photocatalyst, ensuring even light distribution and mitigating fouling. This review not only highlights recent advancements in the removal of PFASs using photocatalysis and membrane separation but also provides comprehensive information on the integration of photocatalysis and membrane separation to form photocatalytic membrane reactors. It emphasizes the performance of immobilized and slurry systems in PFAS removal while also addressing the associated challenges and offering recommendations for improvement. Factors influencing the performance of these methods will be comprehensively discussed, as well as the nanomaterials used for each technology. Additionally, knowledge gaps regarding the removal of PFASs using integrated photocatalytic membrane systems will be addressed, along with a comprehensive discussion on how these technologies can be applied in real-world applications.

Alicyclic Polyimide With Multiple Breakdown Self-Healing Based on Gas-Condensation Phase Validation for High Temperature Capacitive Energy Storage.

Polymer dielectrics with combined thermal stability and self-healing properties are specifically desired for high-temperature film capacitors. The high thermal stability of conventional polymers benefits from the abundance of aromatic rings in the molecule backbone, but the high carbon content sacrifices their self-healing properties. Here, analicyclic polyimide with a high glass transition temperature (256°C) and wide energy bandgap (4.58eV) is designed, which exhibits electric conductivity more than an order of magnitude lower than that of classical polyimide at high electric fields and high temperatures. As a result, alicyclic polyimide achieves a discharged energy density of 4.54 Jcm-3 and a charge-discharge efficiency of above 90% at 200°C, which is superior to existing dielectric polymers and composites. The alicyclic polyimide benefits from a low pyrolytic residual carbon rate, retaining 93% of the dielectric breakdown strength after four electrical breakdown cycles. Distinguishing from the current condensed-phase self-healing concept, for the first time, exploring the self-healing capability of high-temperature polyimide dielectric is presented based on dual self-healing mechanisms of gas-phase and condensed-phase. The high energy density at high temperatures and the superior self-healing capability of alicyclic polyimide further indicate the promise of polyimide dielectric film capacitors for extreme conditions.

Matched Electron-Transport Materials Enabling Efficient and Stable Perovskite Quantum-Dot-Based Light-Emitting Diodes.

Light-emitting diodes (LEDs) based on perovskite quantum dots (QDs), abbreviated as P-QLEDs have been regarded as significantly crucial emitters for lighting and displays. Efficient and stable P-QLEDs still lack ideal electron transport materials (ETM), which could efficiently block hole, transport electron, reduce interface non-radiative recombination and possess high thermal stability. Here, we report 2,4,6-Tris(3'-(pyridine-3-yl) biphenyl-3-yl)-1,3,5-triazine (TmPPPyTz, 3P) with strong electron-withdrawing moieties of pyridine and triazine to modulate the performance of P-QLEDs. Compared with commonly used 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non-radiative recombination caused by the Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole-blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of 3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P-QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2 % and an operational lifetime T50 of 3220 hours at an initial luminance of 100 cd m-2, which is 151 % and about 11-fold improvement compared to control devices (EQE=20 %, T50=297 hours), respectively. These results provide a new concept for constructing the efficient and stable P-QLEDs from the perspective of selective ETM.

Computer-aided design of thermosetting benzoxazoles containing bis-endoalkynyl groups: Low melting points and high thermal stability

High-temperature-resistant polybenzoxazoles (PBOs) have recently become a prominent research area due to their potential applications in aviation and aerospace. However, achieving a balance between thermal stability and processability remains a significant challenge. In this study, a computer-aided method to develop PBOs with high thermal stability and processability is explored. First, thermoset benzoxazoles (CPBOs) are designed using a material genomic approach. Subsequently, their zero shear viscosity, temperature at 50 % thermal weight loss, dielectric constant and dielectric loss are predicted using a computer-aided method. Finally, two screened thermosetting benzoxazoles, CPBO-1 and CPBO-6, are synthesized and experimentally validated. The experiments indicate that their melting points are below 100 °C, with the lowest melt viscosities being 0.5 Pa•s and 1.5 Pa•s, respectively. The corresponding polymers, pCPBO-1 and pCPBO-6, feature high thermal stability. The 5 % weight loss temperature of pCPBO-1 in N2 is 618.9 °C, while the dielectric constant and dielectric loss are 3.1 and 0.0063, respectively. These are excellent values for thermosetting resins. This computer-aided screening method is more efficient and cost-effective compared to conventional trial-and-error methods.

Enhanced thermal stability and corrosion resistance of novel high-entropy spinels in cryolite-alumina molten salt applications

The development of spinel oxide materials with high thermal stability and corrosion resistance is essential for thermochemical reactions, particularly in aluminum electrolysis. This study presents the structural design of a family of high-entropy spinels (HESs) with a stable cubic spinel structure (<i>Fd3‾m</i>), specifically formulated as (Cr5/12 Mn5/12 Fe5/12 Co3/8 Y3/8)3O4, (Y = Ni, Cu, or Zn). Our results demonstrate that these high-entropy spinels significantly outperform conventional NiFe₂O₄, exhibiting superior corrosion resistance and thermal properties. Specifically, we observe lower high-temperature weight loss (0.24 %–0.74 % at 1000 °C), reduced thermal conductivity (1.810–2.258 W m−1 K−1 at room temperature), and lower thermal expansion coefficients (8.2 - 10.7 × 10−6 K−1 from 400 °C to 800 °C), while maintaining comparable specific heat capacities (0.51–0.55 J g−1 K−1). Corrosion testing at 800 °C for 20 h in a KF3-AlF3-Al2O3 molten salt environment shows a corrosion layer thickness of less than 150 μm, with minimal corrosion product formation. These findings not only advance our understanding of material properties under extreme conditions but also pave the way for the development of next-generation materials for thermochemical applications, specifically aimed at improving the efficiency of aluminum electrolysis.