SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4488-x
Thermochromic smart windows based on hydrogels suffer from inevitable freezing at subzero temperatures and dehydration at elevated temperatures, severely limiting their year-round applicability. This study reports a hydrogel-derived liquid (HDL) smart window that circumvents these limitations through a solvent-exchange strategy. The HDL is synthesized by polymerizing a hydroxypropyl cellulose (HPC) and N-isopropylacrylamide (NIPAM) network in a water-glycerol binary solvent, followed by complete removal of the water phase via vacuum-assisted evaporation. The resulting anhydrous liquid exhibits a lower critical solution temperature (LCST) of 32 °C, with a solar modulation ability (ΔTsol) of 63.2% and a luminous transmittance (Tlum) of 88.1% in the clear state. Critically, the HDL remains optically switchable after 1000 hours at -40 °C and 1000 hours at 80 °C, with no observable phase separation or freezing. The smart window prototype demonstrates a 12.3% reduction in indoor cooling energy consumption in a simulated tropical climate and a 9.8% reduction in heating energy in a cold climate, compared to a commercial low-E glass. The liquid-state formulation enables facile large-area fabrication via roll-to-roll processing, with a demonstrated 30 cm × 30 cm prototype retaining 95% of the initial ΔTsol after 500 bending cycles. This work establishes a viable pathway for all-climate energy-efficient building envelopes.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3705-5
Biodegradable metals (BMs) are designed to corrode gradually in physiological environments, yet this corrosion can compromise their mechanical integrity, potentially causing premature implant failure. For emerging zinc-based alloys, the corrosion-mechanical property relationship remains inadequately characterized. This study systematically investigated the long-term corrosion-associated mechanical behavior of hot-extruded Zn-Cu and Zn-Cu-Fe alloys, promising Zn-based bio-metals, in comparison with pure Zn, under immersion degradation in Hank's solution. Electrochemical impedance spectroscopy and mechanical testing revealed that the evolving corrosion profile governs mechanical performance. Alloying with Cu and Fe mitigated corrosion's detrimental effects: grain refinement reduced localized corrosion susceptibility, while finely dispersed second phases acted as cathodic sites, promoting uniform corrosion. Additionally, Cu and Fe facilitated the formation of protective corrosion product layers, suppressing further matrix attack. Consequently, the overall reduced corrosion, particularly localized corrosion, lowered stress concentration susceptibility, delaying mechanical decline and preserving structural integrity. These findings elucidate the degradation-mechanical property correlation in Zn-based bio-metals and underscore critical considerations for developing new bio-metals for clinical translation.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202508013
The Sanshenggong section of the Yellow River is a critical hydrological monitoring and control point, whose water quality directly affects the ecological safety and sustainable water resource utilization of the middle and lower reaches. This study analyzed water quality monitoring data from 2011 to 2024 using the Mann-Kendall test to identify abrupt change years, combined with single-factor evaluation and a fuzzy comprehensive evaluation method improved by CRITIC-entropy weight combination to systematically assess water quality evolution. The Mann-Kendall test identified 2013 and 2019 as abrupt change points, with non-significant improvement from 2013 to 2015 and significant improvement after 2016. Single-factor evaluation indicated that total phosphorus (TP) was the primary exceeding factor in 2011–2012, and its declining concentration drove the water quality upgrade from Class III to Class II in 2013. The CRITIC-entropy weight combination assigned the highest weight (28.96%) to permanganate index, whose decline was the core driver of water quality improvement. The improved fuzzy evaluation showed that the membership degree of Class III water dropped to zero in 2013, indicating stable improvement, but periodic rebounds in Class II membership suggested potential degradation risks. This study provides scientific evidence for ecological protection and high-quality development of the Yellow River Basin.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3792-6
The rapid expansion of home-based digital health monitoring necessitates electrodes capable of simultaneous, accurate acquisition of electrophysiological signals and body temperature. Conventional single-function electrodes, including metal block, gel, and Ag/AgCl types, suffer from limitations such as restricted movement, skin irritation, signal degradation over time, and poor permeability for prolonged use. To overcome these challenges, we developed a low-cost, multifunctional flexible electrode enabling concurrent body temperature and electrophysiological signal monitoring without cross-interference. Body temperature is assessed via visual colorimetric evaluation and precisely measured using a custom smartphone application. The electrode features high air permeability, ultra-thin architecture, superior flexibility, antibacterial properties, and strong skin adhesion, while maintaining low interfacial impedance for stable, long-term acquisition of high-fidelity signals such as electrocardiography (ECG) and surface electromyography (sEMG). Integrated with a Raspberry Pi platform and a hybrid convolutional neural network-long short-term memory (CNN-LSTM) algorithm, the system achieves intelligent arrhythmia detection with 99.30% accuracy. This novel electrode provides a powerful tool for multifunctional sensing of temperature and physiological electrical signals, with significant potential for wearable physiological tracking applications.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3878-5
Borides, exhibiting complex bonding and structural diversity, are promising materials in the fields of ambient superconductivity and hard materials. Although some cage borides with either superhard or superconductivity have been reported, there is still a lack of systematic tuning of the metal centers in regulating their superconductivity and hardness. This study investigates the impact of s-block/d-block metal elements on the superconducting and hardness properties of boron cage lattices under ambient conditions. Using first-principles calculations, we predict a novel class of stable cage-like metallic borides, MB8 (M = Na, Be, Mg, Sr, Sc, Y, Ti, Zr, Hf, V, Nb, Ta) characterized by metal embedded in B–B sublattices composed of 4/8 member B-rings. Superconductivity, hardness, and electronic structure calculations indicate that s-block and d-block metals influence the p-orbital occupancy of B bands, affecting both the electron-phonon coupling (EPC) constant and the bonding strength. In general, within the I422 MB8 (B16 cage) structural family investigated here at ambient pressure, s-block metals enhance the EPC constant (λ) and favour higher superconducting critical temperature (Tc) but weaken the hardness, whereas d-block metals contribute the opposite. Therefore, the Tc of NaB8 reached 24.4 K, which is among the highest values reported for boron cage compounds, while ZrB8 from d-block metals exhibits the highest hardness (21.9 GPa) among. This work proposes a pathway for designing novel superconductors with robust mechanical performance under ambient pressure and elucidates the distinct roles of s-block and d-block metals in modulating the superconductivity and hardness of cage-like borides.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4115-9
The advancement of extreme-condition equipment, such as hypersonic vehicles and next-generation gas turbine engines, imposes stringent requirements on thermal barrier materials, particularly high fracture toughness and low thermal conductivity. However, these properties are often mutually exclusive in oxide ceramics due to their intrinsic ionic and covalent bonding. Conventional strategies to reduce thermal conductivity, such as introducing point defects or porosity, typically degrade mechanical properties, while toughening methods like second-phase or phase transformation toughening can adversely affect thermal transport. Rare earth tantalates and niobates, which exhibit ferroelastic phase transitions, offer promise for ultra-high-temperature applications (>1500°C) due to their unique domain structures that enhance toughness. Yet, weak grain boundary bonding limits the full potential of ferroelastic toughening. Li et al. proposed a high-density dislocation engineering strategy to overcome this trade-off. By introducing dislocations with densities of 10^8–10^10 mm^-2 into (YTaO4)1-x/(Y3TaO7)x (x=0.1–0.6) composite ceramics via spark plasma sintering and subsequent heat treatment, they achieved significant reductions in thermal conductivity through phonon scattering while simultaneously enhancing fracture toughness via crack deflection and energy dissipation. This work successfully decouples thermal and mechanical performance, offering a new paradigm for microstructural design in thermal protection materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4221-y
The advancement of 5G/6G communications and hypersonic vehicle technology imposes stringent requirements on electromagnetic wave absorbing materials, demanding efficient low-frequency (C-band, 4–8 GHz) response and stable performance above 500°C in oxidizing environments. Traditional absorbers face inherent contradictions: carbon-based composites suffer oxidation, magnetic materials lose function above Curie temperature, and ceramics like SiOC exhibit poor low-frequency absorption due to single dielectric loss. Zeng et al. (Adv Mater, 2026) propose a nitrogen-induced evolution from Fe nanoparticles to Fe single atoms within SiOC ceramic fibers. Through electrospinning of polycarbosilane, PVP, and iron(III) acetylacetonate, followed by curing at 200°C and pyrolysis at 1000°C with dicyandiamide as nitrogen source, they achieve Fe-N4 single-atom coordination. EXAFS confirms Fe-N peak at ~1.5 Å and absence of Fe-Fe peak at ~2.2 Å, ruling out clusters. This design leverages strong Fe-N covalent bonds and unique electronic structure, retaining magnetic contribution to low-frequency response while preventing nanoparticle agglomeration and oxidation. The work achieves synergistic breakthrough in low-frequency absorption and high-temperature stability, pioneering design for extreme environments.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4132-y
Manganese-iron-based mixed polyanionic cathodes are promising for sodium-ion batteries (SIBs) due to high energy density and operating voltage, but suffer from Jahn-Teller distortion of Mn3+ that degrades cycling stability. Here, a structural modulation strategy via Mg2+ doping is reported. Electrochemically inert Mg2+ forms stronger chemical bonds, adjusts lattice parameters, and suppresses Jahn-Teller distortion, enhancing structural stability. Mg2+ also widens sodium-ion diffusion channels, improving diffusion kinetics. Additionally, an in-situ three-dimensional carbon nanotube (CNT) conductive network boosts electronic conductivity. The resulting NFMPP-Mg@CNTs cathode delivers a discharge capacity of 126 mAh g−1 at 0.1 C (near theoretical 129 mAh g−1), retains 80% capacity after 3000 cycles at 0.5 C, and achieves an energy density of 401 Wh kg−1, among the highest reported for mixed phosphate systems. Ex-situ XPS and first-principles calculations confirm that Mg2+ resists geometric distortion by enhancing lattice stability and widening Na+ diffusion pathways (migration barrier reduced from 0.566 to 0.398 eV). This work provides a viable route for high-energy, long-life SIB cathodes suitable for large-scale energy storage.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3376-9
Solid-state batteries (SSBs) pairing lithium metal anodes with high-voltage cathodes promise higher energy density and safety than liquid-electrolyte lithium-ion batteries. Polymer electrolytes (PEs) are pivotal due to flexibility, processability, and conformal electrode contact. However, high interfacial resistance, lithium dendrite growth, inactive dead lithium, and parasitic side reactions—especially with high-voltage cathodes—severely limit PE-based SSBs. These failures stem from concentration heterogeneity (concentration polarization) and chemical heterogeneity at the electrode/PE interface during operation. Concentration gradients produce non-uniform Li-ion flux, creating localized hot spots that trigger dendrite formation and electrolyte decomposition. Chemical heterogeneity from spatially non-uniform side reactions dictates the nature and effectiveness of the solid electrolyte interphase (SEI) or cathode electrolyte interphase (CEI). Probing the evolution of these heterogeneities at buried solid/solid interfaces with chemical specificity and spatial resolution in functional cells remains a significant challenge. Lin et al. (Nat Nanotechnol, 2025, 20, 787–797) reported a molecular ionic composite (MIC) electrolyte—a rigid-rod ionic polymer (PBDT) network, an ionic liquid (Pyr14TFSI), and LiTFSI—as a model multiphase system. Using X-ray fluorescence (XRF) microscopy and X-ray absorption spectroscopy (XAS), they mapped sulfur distribution across Li|PE|NCM811 cross-sections. After 200 cycles, sulfur-depleted regions emerged near both electrodes, more severe at the Li metal side, indicating TFSI− anion depletion and local phase separation that compromises structural integrity and ionic transport. This work establishes interfacial chemomechanics as a governing factor for PE-based SSB stability.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3751-6
Ionogels, which integrate the flexibility and ionic conductivity of ionic liquids with the mechanical robustness of polymer networks, have emerged as pivotal materials for flexible electronics. Their tissue-like biomechanical characteristics enable applications in health monitoring, smart wearables, and human-machine interfaces. However, ionogels are susceptible to mechanical damage under large deformations and continuous loading, leading to structural failure and device degradation. Self-healing capability, imparted through dynamic non-covalent bonds (hydrogen bonds, ionic interactions) and reversible covalent bonds, can significantly enhance device reliability, service life, and safety. This review systematically examines the latest progress in self-healing ionogels (SHIGs), covering self-healing mechanisms, design strategies, and preparation methods. Key applications are analyzed, including wearable strain sensors, flexible triboelectric nanogenerators, supercapacitors, flexible displays, and soft robots. The review highlights recent breakthroughs, such as rapid self-healing (within minutes) and superior toughness (fracture energy exceeding 10 kJ m⁻²) in ionically crosslinked polymer ionogels, and record-breaking mechanical properties in room-temperature self-healing ionogels inspired by sea cucumber dermis. Despite these advances, challenges persist in balancing self-healing efficiency with mechanical strength, achieving cost-effective scalability, and ensuring long-term stability under extreme conditions. Perspectives on future development are provided, emphasizing the need for multifunctional integration and standardized testing protocols to accelerate the commercialization of self-healing ionogels in next-generation flexible electronics.