In this study, vacuum impregnation was employed to modify the surface of spherical zircon aggregates with alumina sol. Experimental results demonstrated that the incorporation of alumina sol transformed the initially homogeneous aggregate structure into a core-shell architecture, wherein the core consisted of zircon and the shell was composed of mullite. Specifically, the introduced Al2O3 accelerated the decomposition of zircon; the SiO2 generated from this decomposition then underwent an in-situ reaction with Al2O3 to form mullite. The structural modification not only enhanced the sintering behavior of the aggregates but also improved overall performance. Additionally, the formation of mullite structure on the aggregate surface further contributed to the performance enhancement of zircon aggregates. After undergoing the surface modification, the zircon aggregates exhibited a marked reduction in apparent porosity alongside a high cylinder compressive strength retention rate; these favorable performance characteristics were conducive to the practical utilization in the fabrication of refractories.

The growing demand for multifunctional lightweight materials integrating electromagnetic (EM) wave absorption, impact resistance, thermal insulation, and self-cleaning poses significant challenges due to structural and processing trade-offs. This study proposes a bi-thermoplastic expanding microsphere (Bi-TEM) mold-opening foaming (BTMOF) strategy to fabricate polypropylene/carbon nanotube/Fe3O4 (PP/CNT/Fe3O4) composite foams with oriented bimodal cells and barbule-like surface topology in a single step. The synergistic foaming of high- and low-temperature TEMs under mold-opening stress creates an oriented bimodal structure, while in-mold micro-template imprinting spontaneously constructs superhydrophobic surface microstructures. The oriented bimodal cells extend EM wave propagation paths, achieving a reflection loss (RL) of -47.82 dB and an effective absorption bandwidth (EAB) of 5.04 GHz using enhanced interfacial polarization and multiple reflections. The structure also enables 92.06 % impact energy absorption efficiency through progressive folding and reduces thermal conductivity to 0.0336 W/(m K) by phonon scattering. Meanwhile, the barbule-like surface ensures super-hydrophobicity (contact angle of 161.6 degrees; sliding angle of 3 degrees), rendering the foam self-cleaning attributes. This BTMOF approach overcomes traditional scalability limitations, offering a facile route to fabricate multifunctional foams for aerospace, defense, and wearable electronics sectors.

While the beta phase of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is promising for enhancing the elasticity and toughness of the material, its stability and the phase transition between beta and alpha-phase remain under hot debate. In this work, the stability of beta phase in solid-state stretched PHBHHx upon heating, as well as the phase transition between beta and alpha-phase during strain recovery and creep were studied via in-situ WAXS and polarized FTIR. The absence of beta phase characteristic in perpendicular FTIR spectra revealed that beta phase is primarily highly oriented along the stretching direction. Upon heating, the contents of both beta and alpha-phases begin to decrease as the temperature reaches the alpha c-relaxation temperature of the stretched PHBHHx. This disappearance proceeds in a stepwise manner involving conformational adjustments of the chain backbone and ester groups, alongside weakened interchain interactions. Furthermore, a phase transition between beta and alpha-phase was observed during strain recovery and creep, governed by a similar stepwise process accompanied by conformational and interchain interaction changes. Critically, the beta phase content varies linearly with strain recovery or creep displacement, providing substantial evidence that the phase transition is consistent with a viscoplastic flow-controlled process in the stretched PHBHHx.

Due to high mechanical strength/fatigue resistance, ultra-high molecular weight polyethylene (UHMWPE) fiber-based soft actuator is crucial for developing advanced smart devices. However, strategies for self-powered sensing response and durable actuating function remain challenging. Herein, a novel UHMWPE fiber-based soft actuator with durable and reversible photothermal actuating functions was prepared by constructing tailored oriented crystalline structure, engineering precise twisted/coiled geometries, and applying an efficient photothermal-conversion polypyrrole (PPy) coating. With increasing draw ratio, rod-shaped nucleating agent (SNA) assemblies preferentially aligned and induced UHMWPE molecules to form a highly oriented and thermally stable epitaxial crystalline structure (hybrid shish-kebab crystals) for the fibers, while controlling twisting/coiling geometries and enabling the in-situ growth of PPy coating, PPy@UHMWPE-SNA soft actuator with rapid photothermal response and excellent actuating performance was obtained. Under 100 mW/cm2 sunlight illumination, the maximum recoverable shrinkage strain and work capacity of PPy@UHMWPE-SNA-1000% soft actuator achieved 62.21% and 80.46 J/kg, corresponding to 309% and 1007% of the typical values for mammalian skeletal muscle. Furthermore, the SNA assemblies effectively stabilized the oriented crystalline structure during multiple photothermal stimulation, which endowed the soft actuator with durable and reversible photothermal actuating function.

The uncontrolled and randomized propagation of electromagnetic microwaves (EMW) in conventional polymer-based porous absorbers critically limits their dissipation efficiency, directional attenuation, and deep capture capability. Herein, we propose a vacuum-counter pressure-assisted strategy that transforms regular polygonal cells into re-entrant structures, enabling directional wave guidance and trap-based capture. The re-entrant cell corners form sharp edges that trigger a "blade reflection" mode, facilitating the directional propagation of EMW along predefined paths. Along these paths, BaTiO3-based microcapacitors embedded within the cell walls induce additional loss. Through the synergy of directional guidance and microcapacitor traps, the re-entrant foam achieves a minimum reflection loss (RLmin) of-51.85 dB and a 4.75 GHz effective absorption bandwidth (EAB) at a low density of 0.31 g cm-3, dramatically surpassing conventional designs. Moreover, under compression and impact, the re-entrant structure undergoes inward lateral contraction that drives localized densification, improving load-bearing capacity, damage resistance, and overall robustness, enabling long-term mechanical stability in practical applications. This work establishes a dissipation paradigm driven by the synergy of directional wave guidance and microcapacitor induced loss, allowing a transition from uncontrolled to directional EMW attenuation, and offers a design framework for lightweight, high-efficiency, directionally functional porous EMW absorbers.

This study systematically investigated the differences in mechanical properties, slag corrosion resistance, and oxidation resistance of MgO-C refractories incorporated with two types of anti-oxidants, namely silicon (Si, labeled as S) and silicon carbide (SiC, labeled as SC) powders. The corrosion characteristics of MgO-C refractories exposed to slags with low basicity were also analyzed. After high-temperature heat treatment at varied temperatures, sample SC possessed higher mechanical strength than sample S. Owing to the relatively low oxidation rate of SiC powder, sample SC presented inferior oxidation resistance and a wider transition zone. In addition, the reaction between Si powder and graphite led to the formation of a porous microstructure in the matrix. Consequently, the matrix of sample S suffered severe slag erosion and structural damage. Overall, sample SC exhibited superior resistance to slag penetration and corrosion compared with sample S. Thermodynamic simulation results revealed that slag basicity regulated the content and viscosity of the liquid phase generated during high-temperature reactions, which further caused distinct differences in the slag penetration resistance of the two refractories. Notably, sample SC achieved the optimal slag penetration resistance at a slag basicity of 1.5.

High energy consumption and complex processes constrain the industrial production of high-performance SiC/SiO2 fibers. A direct synthesis route for SiC/SiO2 fibers at low temperatures (700-1100 °C) is developed in this work using pure-material microwave heating without external heating assistance. The phase composition, microstructure, and microwave-assisted synthesis process of the fibers were systematically investigated. A two-stage growth mechanism is proposed based on real-time microwave coupling analysis, consisting of kinetically controlled SiC fiber growth followed by thermodynamically driven SiO2 bead formation. The SiC/SiO2 fibers synthesized at 1000 °C exhibit outstanding electromagnetic wave absorption performance, achieving a minimum reflection loss (RL min) of -42.49 dB at an ultrathin thickness of 2.9 mm, demonstrating great potential for lightweight, high-efficiency microwave absorbers.

High-entropy monoborides have attracted significant attention owing to their exceptional hardness that defies the conventional trends of boron-content-dependent hardness. Yet, comprehensive understanding of the atomic-scale formation and hardening mechanisms and their links to the macroscopic properties, is lacking. The high-entropy design strategy offers a revolutionary approach to address this challenge. In this study, a single-phase high-entropy monoboride (V0.2Cr0.2Mo0.2W0.2Ni0.2)B with a CrB-type structure is successfully synthesized via reactive hot-pressing sintering. A combined multiscale characterization and first-principles-calculation approach is employed to systematically elucidate the deep-rooted relationships among the formation mechanism, chemical bonding, and macroscopic properties. The CrB-type structure is observed to exhibit entropy-stabilization characteristics governed by the minimal standard deviation of the local mixing-enthalpy distribution (0.0241 eV/ atom), providing evidence for entropy-driven stabilization in high-entropy monoborides from a uniform-energy-distribution perspective. Electronic-structure analysis reveals a coexisting bonding framework comprising strong B-B covalent bonds, polar metal-boron bonds (W/Mo/Cr/V-B), and a metallic bonding network optimized by Ni, which collectively construct a rigid structural framework, endowing the material with a theoretical hardness of 25.87 GPa. Notably, Ni plays a dual role in thermal transport: its delocalized D-electrons facilitate electronic conduction, while the high-entropy-induced lattice distortion enhances phonon scattering, leading to a low room-temperature thermal conductivity of 10.832 W/(m & sdot;K) without compromising hardness. The material also demonstrates excellent thermal stability with a coefficient of thermal expansion of (9.130 +/- 0.025) x 10-6 /K. This work provides a quantitative structure-property framework, offering a new design paradigm for high-hardness, low-thermal-conductivity ceramics with tunable heat-transport properties.

Superhydrophobic surfaces have garnered extensive attention due to multifunctional applications. However, traditional fabrication strategies involve wet-based processing of hydrophobic polymers, resulting in heavy reliance on organic solvents, which raises environmental concerns. Here, a robust and durable water-based superhydrophobic coating applicable to various substrates was developed by achieving stable aqueous system of fluorosilane functionalized SiO2 nanoparticles using cellulose nanofiber as dispersion agent. After spraycoating, fluorosilane with low surface energy triggered partial SiO2 aggregation into micron-scale architectures, forming micro/nanoscale hierarchical structure, which endowed the coated cellulose-based substrates with superhydrophobicity, self-cleaning and anti-fouling performances. The coating revealed outstanding chemical and mechanical durability after exposing to solutions with different pH and 50 cycles of sandpaper abrasion (600 grit)/120 min ultrasonic treatment (300 W). Besides, the superhydrophobic coating was applied to fabricate durable hydrophobic urea-formaldehyde foam, enabling application in building insulation. Multifunctionality along with durability of such water-based superhydrophobic coating shows promise for practical applications.

To facilitate the next generation of renewable energy devices, it is important to engineer oxygen reduction reaction (ORR) catalysts that balance efficiency and production costs. This work examines oxygen adsorption on the WC (0001) surface as a function of electrode potential, utilizing DFT simulations with an implicit solvent environment. The results demonstrate that electrode potential significantly influences oxygen adsorption energy and electronic structure. Among the adsorption sites examined, the top site exhibits the highest stability across the entire potential range. The observed reduction in adsorption energy at lower potentials is attributed to the d-band center moving further from the Fermi energy, which weakens C-O orbital interactions, as revealed by DOS and COHP analyses. Our results demonstrate the crucial role of electrochemical conditions in modulating catalytic behavior and provide valuable insights for optimizing tungsten carbide (WC)-based electrocatalysts for ORR applications.

Polymer processing technology serves as a cornerstone of manufacturing industry. In polymer processing, macroscopic properties and quality are governed by structural evolution at the micro- and mesoscopic scales. However, significant differences exist in the physical mechanisms and governing equations across different scales, and it is known as the “scale issue”. The primary objective of this review is to summarize recent advancements in addressing scale issues and analytical methods in polymer processing. The perspective primarily focuses on multi-scale analysis and cross-scale correlation. Herein, we systematically reviewed typical scale effects and associated issues on the aspects of macro-, meso-, and microscopic. The analysis methods of multi-scale and cross-scale were listed. The key points on the cross-scale method’s perspectives were identified in the end. Overall, this paper provides a valuable resource for researchers to reveal the underlying mechanisms at different scales, highlighting advancements and challenges in this rapidly evolving area.

The rapid evolution of intelligent electromagnetic systems has heightened the performance standards for observation windows, driving a demand for flexible, multifunctional, transparent EMI shielding films with robust environmental durability, while current progress remains a significant challenge. In this study, a multifunctional transparent EMI shielding film composed of silver nanowire (AgNW) and polydimethylsiloxane (PDMS) with an embedded conductive network was fabricated via a two-step process involving rotational spraying followed by infiltration transfer. The resulting AgNW/PDMS film exhibits high optical transmittance (71.1%) and low sheet resistance (11.3 Ω/sq), combined with average EMI shielding effectiveness (EMI SE) of 30.2 dB in the X-band, 32.6 dB in the Ku-band, and 34.5 dB in the K-band. The synergistic effect of PDMS-induced physical confinement and hydrogen bonding markedly enhances the interfacial adhesion and antioxidant capacity of the transparent shielding film, contributing to the reliability and durability in harsh environments. Simultaneously, the strain-induced reconfiguration of the AgNW network and the resultant adaptive conductivity modulation synergistically enable the film to exhibit exceptional strain-sensing performance and efficient Joule heating functionality. The multifunctional integration clearly demonstrates that transparent shielding films possess significant potential for enabling iterative improvements in observation window systems across aerospace, automotive, and next-generation electronic device applications.

The dependence of phase morphology on poly(D-lactic acid) (PDLA) content (phi D) in poly(L-lactic acid) (PLLA)/ PDLA blends is investigated, along with the interplay between isothermal crystallization and phase separation. Results demonstrates that the two-phase morphology appears when phi D exceeds 25 wt%. As phi D increases from 37 to 50 wt%, the phase morphology transfers from "sea-island" to "co-continuous". Notably, blends owning distinct two-phase morphology display a two-stage crystallization behavior during isothermal crystallization at temperature of 115-160 degrees C. Further investigation by in-situ wide-angle X-ray scattering analysis confirms that both peaks are originated from the crystallization of homo-crystallites (HC). Polarized optical microscopy reveals that the spherulite diameter (D) follows a power-law relationship with the crystallization time (t), i.e. D proportional to t1/2, indicting the existence of the Mullins-Sekerka-type instability at the growth front of spherulites. This instability, widely observed in binary polymer blends, arises when the immiscible counter-phase is expelled from the growing spherulite, which conversely reconstruct the phase morphology of the remaining amorphous region. Taking the dependence of the melting point on the crystallization temperature, the crystal form constitution during isothermal crystallization, and the growth rate into consideration, the first crystallization peak is ascribed to the HC formation in regions confined by previously formed SC or phase boundaries, while the second peak to the crystallization of HC in more homogeneous region after phase reconstruction. These findings not only confirm the immiscibility of PLLA and PDLA in the blend, but also offer new insight into the complex coupling between phase separation and crystallization processes.

Si2N2O combines both oxide and non-oxide properties, giving the material excellent mechanical properties and chemical stability, making it a new candidate for material improvement. This paper investigates the effect of introducing ferrosilicon nitride on the formation mechanism of in situ synthesized Si2N2O and the mechanical properties of lightweight spinel-based composites. The results show that thermodynamic calculations of the Si-NO-C system reveal the formation patterns of Si2N2O with the formation between CO and N2. Incorporating ferrosilicon nitride leads to the formation of SiC whiskers and Si2N2O at 1600 degrees C. Density functional theory (DFT) suggests that ferrosilicon nitride can reduce oxygen adsorption energy on the (200) crystal face of silicon nitride, thereby accelerating the conversion of silicon nitride to Si2N2O. Optimum mechanical properties are achieved at 0.6 wt% of ferrosilicon nitride, with cold crush strength (CCS) and cold modulus of rupture (CMOR) reaching 202.1 MPa and 29.5 MPa, respectively. At the same time, the hot modulus of rupture (HMOR) of the specimens increases by 26 % to a maximum of 16.6 MPa. After three times thermal shock cycles, the specimens show a high residual strength ratio, reaching 86 %.

Beta-hemihydrate desulfurization gypsum (beta-HDG) is considered one of the green and low-carbon building materials, which is widely used in the fields of construction materials and decoration. Nevertheless, its inherent deficiency in water resistance and other drawbacks significantly limit its application scope. In this study, the gypsum-based materials with surfaces that exhibit hydrophobic properties were prepared. The surface contact angle was analyzed to examine the surface hydrophobic characteristics. The compressive strength, flexural strength, ratio of compressive strength to flexural strength, water absorption rate, and softening coefficient of hardened specimens were measured to assess the mechanical properties. Furthermore, the pore structure and microstructure of hardened specimens were characterized to evaluate the impact of hydrophobically modified reduced graphene oxide (H@rGO). Furthermore, when the content of H@rGO was 0.15 wt%, the thermal conductivity of specimen was 0.55 W/m center dot K with optimal mechanical properties; the surface hydrophobicity of the hardened sample was significantly improved, with the surface contact angle, water drop penetration time, and softening coefficient reaching 113.898 degrees, 567s, and 0.77, respectively. This enhancement was accompanied by a reduction in pore size and total porosity in the hardened samples, thereby contributing to the improved softening coefficient and mechanical properties of gypsum-based composites. Because of lower energy consumption in H@rGO process and extensive utilization of industrial solid waste, the preparation process of incorporating H@rGO into beta-HDG exhibits superior cost-effectiveness.

Gypsum products are a lightweight, low-cost, and environmentally friendly material. Owing to the high porosity of its microstructure, the water resistance and wear resistance of gypsum products are relatively poor. This study investigates the influence of silicon carbide (SiC) particles of different fineness, including 200-mesh, 300-mesh, and superfine, on the hydration and hardening properties of gypsum-based composites. The results show that compared to the control sample, the rate of gypsum hydration changed with the different fineness of SiC particles. With the addition of 5 wt% 200-mesh SiC and superfine SiC, the initial setting time of gypsum slurry increase by 19.6 % and decreased by 33.2 %, respectively. SiC significantly improved the mechanical properties, waterproofing and wear resistance of hardened gypsum specimens, with the finer particles resulting in more evident effect. With the addition of 5 wt% superfine SiC, the compressive strength and wear resistance can be improved in 38.8 % and 80.3 %, respectively. SiC particles did not alter the phase of the main hydration products of the specimens; rather, they changed the crystal structure of calcium sulfate dihydrate and filled the crystal pores, thereby densifying its overall structure. The results are useful for improving the mechanical properties, especially the wear characteristics of gypsum-based materials.

The development of electrodes with low cost, high stability and efficient catalytic performance is crucial for the practical application of hydrogen production by electrolyzing water. Here, we reported the preparation of a novel MoS2/WC ceramic electrode with a straight-through hole structure by phase-inversion tape-casting combined with hydrothermal method. The obtained MoS2/WC electrode achieved impressive HER performance under acidic conditions, specifically with an overpotential of only 215 mV at a current density of 500 mA cm-2, demonstrating excellent high current density catalytic activity. Furthermore, the ceramic electrode demonstrated excellent long-term stability, operating reliably for 600 h across a current density range of 10-500 mA cm-2. The outstanding catalytic activity and stability at high current densities are primarily attributed to the through-hole structure, which enhances mass transfer of the electrolyte and gas bubbles, along with the increased number of active sites provided by MoS2 nanoflakes. Therefore, the prepared ceramic electrode has great potential for the development of industrial hydrogen production electrodes.