Science and Technology of Advanced Materials最新文献

The p-type thermoelectric (TE) material α-MgAgSb is a promising tellurium-free bismuth telluride substitute for cooling and waste heat harvesting applications between room temperature and 573 K. Optimization of the material resulted in high values of figure of merit (zT _max = 1.3) to date, but performance optimization of TE devices also requires minimizing the electrical contact resistance between the TE material and the electrodes. Here, we investigate the metallization of MgAgSb with MgCuSb, providing microstructural and electrical analyses of the interfaces for functionalized legs obtained from a combined sintering of both materials systematically varying temperature, duration and pressure. Analysis of the obtained results reveals the formation of an interdiffusion layer of Ag₃Sb with varying thickness in all samples, but the contact resistance remains consistently below 10 μΩ cm². Microprobe measurements of the Seebeck coefficient indicate a change in carrier concentration in the TE material close to the interface, visualizing interdiffusion processes between MgAgSb and MgCuSb. We furthermore demonstrate that MgCuSb can successfully be applied as an electrode on pre-compacted MgAgSb samples, resulting in the first ever reported successful two-step contacting of MgAgSb. The obtained sample exhibits a strong mechanical contact without any crack at the interface, as well as a very low electrical contact resistance below 7 µΩ cm², representing less than 5% of the total leg resistance. Successful contacting of pre-compacted material is a step forward towards module fabrication as it enables better control of the TE leg length and thus device performance.

While high-voltage operation of mid-Ni layered oxide cathodes in full-cell Li-ion batteries is essential for achieving high energy density, it inevitably accelerates electrode degradation, ultimately resulting in capacity loss. However, the underlying degradation mechanisms under high-voltage conditions remain poorly understood. In this study, we reveal that anode slippage - induced by cross-talk-driven surface degradation - is the dominant factor in capacity fade during high-voltage (4.35 or 4.40 V) cycling of single-crystal mid-Ni layered oxide (SC-NCM)/graphite pouch full-cells. Electrochemical and post-mortem analyses show that, although high-voltage operation induces cathode surface degradation, including lattice oxygen loss and phase transitions, its direct impact on capacity loss is relatively minor compared to that of the anode. Instead, anode degradation is primarily caused by cross-talk effects from cathode Ni dissolution, which promote the accumulation of irreversible organic byproducts - such as LiOx and Li₂CO₃ - within the solid electrolyte interphase (SEI) layer of the graphite anode. This leads to increased resistance and reduced anode electrochemical activity, disrupting electrode balance and accelerating full-cell capacity fade. These findings highlight the critical role of anode degradation in high-voltage operation and emphasize the importance of mitigating cross-talk effects. A comprehensive understanding of cross-talk-induced anode slippage is therefore critical for the rational design of high-voltage mid-Ni full-cell systems with long-term durability.

Active matter, characterized by its ability to exhibit autonomous and dynamic behavior, has emerged as a promising platform for mimicking complex biological processes. In biological systems, electrochemical signaling plays a vital role in regulating their dynamic processes, such as muscle contraction. Drawing inspiration from these mechanisms, we demonstrate that electrochemical signaling can effectively modulate the autonomous motion of self-oscillating gels (SOGs), a model active matter system driven by the Belousov - Zhabotinsky reaction. Electrochemical stimulation generates signal transducers, HBrO₂ and Br^-, enabling the modulation of the autonomous motion of SOGs, including the termination and acceleration of volumetric oscillations. Our findings reveal that the response of SOGs to electrochemical signals is influenced by their geometry, orientation, and the duration of applied potential. These results establish electrochemical signaling as a powerful approach for controlling the behavior of active matter, bridging the gap between synthetic systems and biological mechanisms. By advancing the understanding of active matter dynamics, this work paves the way for applications in soft robotics, adaptive materials, and bioinspired actuators.

Ionic self-assembly (ISA) has emerged as a powerful nanoarchitectonics strategy for constructing functional supramolecular materials through electrostatic interactions. This approach enables the formation of highly ordered nano- and mesostructures with tunable electrochemical properties. A key application of ISA lies in electroactive polyelectrolyte-surfactant complexes, which serve as dynamic platforms for biosensing and electrochemical devices. These materials, easily integrated onto electrodes via solution-based deposition techniques, offer tailored charge transport and redox activity. Their ability to incorporate metal nanoparticles and enzymes further expands their functionality, enabling the development of amperometric biosensors for highly sensitive biochemical detection. This review explores the principles of ISA-derived materials, emphasizing their role in electrochemical applications and their potential in next-generation biosensors.

The excessive accumulation of monosodium urate crystals in joints leads to the pathological condition known as gout. While conventional treatments, which include Non-steroidal Anti-inflammatory Drugs, are available, their short half-life and low bioavailability limit their practical application. To overcome these limitations and leverage the Reactive Oxygen Species (ROS)-rich microenvironment, this study developed a novel ROS-responsive thioketal-linked hyaluronic acid-based micelle loaded with manganese oxide (HTO-MnO) for enhanced treatment. Following the synthesis of the HTO-MnO nanocomplex, the micelle was well characterized and the synthesized micelle were subjected to multiple tests to confirm their efficacy in reducing ROS. In addition, the in-vitro treatment of M1-polarized macrophages showed significant responses at both the gene and protein expression levels. Eventually, in-vivo analysis of the HTO-MnO nanoparticles was performed in the MSU-induced arthritis mouse model. The elevated ROS levels in the ankle joint of the mice triggered the release of MnO nanoparticles from the HTO micelles, suppressing the ROS levels and repolarizing macrophages to their M0 state, thereby effectively mitigating inflammation. This study demonstrates the potential of nanocomplex to reduce ankle swelling and intrinsic ROS levels by targeting M1 macrophages. The results highlight its precise therapeutic mechanism to alleviate inflammation and treat gouty arthritis.

In living systems, dynamic biomacromolecular assemblies are driven and regulated by energy dissipative chemical reaction networks, enabling various autonomous functions. Inspired by this biological principle, we report a chemically-fueled phase transition of a poly(N-isopropylacrylamide) (PNIPAAm)-based polymer bearing viologen units (P(NIPAAm-V)), wherein redox changes drive coil-to-globule phase transitions. Upon the addition of a reducing agent, viologen moieties in P(NIPAAm-V) are converted into their reduced state, resulting in enhanced hydrophobicity and polymer aggregation. Coexistence of a platinum catalyst couples these redox-driven structural changes to hydrogen evolution, which oxidizes the viologen radicals, thus restoring the polymer chains to their hydrated random coil state. As a result, transient polymer assemblies form and subsequently disassemble upon depletion of the reducing agent, leading to a temporally controlled out-of-equilibrium phase transition. Moreover, by tuning the platinum concentration and reaction temperature, we achieve precise control of both the size and lifetime of these assemblies. Notably, viologen moieties constitute only about 1% of the polymer repeating units, underscoring that chemically-fueled phase transition is efficient strategy for dynamically regulating molecular assemblies. These findings demonstrate that chemically-fueled phase transitions in redox-responsive polymers offer a promising blueprint for designing dynamic, biomimetic materials capable of spatiotemporally regulated structural transformations.

In the development of renewable energy sources, batteries are considered the best option for energy storage. High energy density and high performance are key demands for emerging technologies. Lithium-metal batteries (LMBs) are considered promising candidates for storing generated energy. However, the formation of lithium dendrites and infinite volume expansion during cycling are serious limitations in current LMB applications. 3D-structured anodes have received considerable attention as an effective solution to overcome these problems. Herein, we synthesize a lithiophilic 3D-Si/SiO_x host for LMBs via a simple magnesiothermic reduction process (MRP). The 3D porous SiO_x structure provides a large specific surface area, which reduces local current density and offers ample space for Li deposition. The 3D-Si/SiO_x anode not only accommodates volume changes but also demonstrates homogeneous, dendrite-free lithium deposition with a high coulombic efficiency of more than 99% at 0.1, 0.5, and 1.0C. The symmetric cell composed of prelithiated (4 mAh/cm²) 3D-Si/SiO_x shows stable long-cycle performance for over 350 hours. By utilizing a single porous particle material with surface-limited lithiophilic properties, rather than the conventional complex 3D lithium anode designs (which typically involve hierarchical structures and lithium-friendly seed materials), this work provides new insights into the design of 3D lithium metal anodes.

Inhaled nitric oxide (iNO) is a powerful therapy for the treatment of various cardiopulmonary and respiratory diseases. However, access to iNO therapy is often limited by the necessity of cumbersome gas tanks and/or elaborate gas blending apparatus. Here, we report a lightweight, inexpensive, and maintenance-free tablet that autonomously generates a therapeutic quantity of NO in air. The tablet is composed of a thimble filter paper containing a powdery mixture of nitrite (NO₂ ^‒)-type layered double hydroxide (NLDH) and ascorbic acid loaded on silica gel (AASiO₂). NLDH by itself generates trace amounts of NO in the air due to the left-shifting of the protonation equilibrium of NO₂ ^‒ by aerial CO₂ and H₂O (2[NO₂ ^‒]_LDH + CO₂ + H₂O $\rightleftharpoons$ 2HNO₂↑ + [CO₃ ^2‒]_LDH), which is followed by disproportionation of 2HNO₂ to NO, NO₂ and H₂O. In contrast, it was found that the protonation equilibrium can be shifted to the right side when volatile acid products (HNO₂ and NO₂) are readily converted to neutral NO over the AASiO₂ reductant. Based on this, even a single tablet (containing 0.30 g NLDH and 0.90 g AASiO₂) generates 5 ~ 20 ppm NO at 0.5 L/min for 24 h, which is sufficient to be useful for the relief of severe hypoxia caused by persistent pulmonary hypertension of the newborn (PPHN). Moreover, the tablet can be activated by exhaled breath for high-dose iNO therapy (80 ~ 180 ppm for several hours), revealing its potential utility for treating viral pneumonia. The NO tablet can be stored stably over long periods at ambient temperature in a gas barrier bag and has the potential to break the logistical, financial, and operational barriers that have long existed for the widespread implementation of iNO therapy.

We demonstrated the epitaxial lateral overgrowth of m-plane α-Ga₂O₃ using halide vapor phase epitaxy. An m-plane α-Ga₂O₃/sapphire template with a patterned SiO₂ mask was used as the substrate. The highest lateral growth rate for a radial spoke-wheel patterned mask was obtained when the spoke was perpendicular to the $\left(11\stackrel{-}{2}3\right)$ direction. In this case, the lateral-to-vertical growth rate ratio (L/V ratio), with L defined as the rate of increase in the width of an elongated α-Ga₂O₃ island, was as large as 5.8. This ratio was greater than that reported for an m-direction stripe mask on a-plane α-Ga₂O₃ by a factor of 3.3 and that for an a-direction stripe mask on c- and m-plane α-Ga₂O₃ by a factor of 13. The epitaxial lateral overgrowth (ELO) of α-Ga₂O₃ on a stripe mask (window/mask widths of 2.5 μm/7.5 μm) perpendicular to $\left(11\stackrel{-}{2}3\right)$ resulted in the selective nucleation of elongated α-Ga₂O₃ islands with a flat triangular cross-section on the window areas and their coalescence into a compact film. Transmission electron microscopy revealed that the dislocation density in the laterally grown area decreased drastically because the propagation of dislocations in the seed layer was effectively blocked by the mask. We believe these results greatly contribute to the realization of m-plane α-Ga₂O₃-based future power devices.

Extracellular vesicles (EVs) hold significant promise as biomarkers and therapeutics, yet their isolation remains challenging due to their low abundance and complex sample matrices. Here, we introduce EV-Osmoprocessor (EVOs), a novel device that leverages osmosis-driven filtration for rapid and efficient EV isolation. EVOs employs a high osmolarity polymer solution to concentrate EVs while simultaneously removing smaller contaminants. Compared to traditional methods such as ultracentrifugation and precipitation, EVOs offers speed and convenience, achieving a 50-fold volume reduction in under 2 h. Our results show that EVOs retained EVs and removed >99% albumin from the cell conditioned culture medium (CCM). The isolated EVs exhibited a particle size distribution centered around 140 nm, which was very similar to EVs isolated via precipitation or ultracentrifugation. The standalone EVOs process achieved a particle:protein ratio (EV purity) of ~10⁷ particles/µg protein. Comprehensive characterization, including cryo-electron microscopy, validation of protein markers and known miRNA cargo confirmed the successful isolation of EVs. Functional assays, based on protection of cardiomyocytes from hypoxia/reoxygenation injury, demonstrated the bioactivity of EVOs-isolated EVs. Furthermore, we show that EVOs can be used to concentrate 30 ml of CCM into a 0.5 ml solution, which was then further processed with size-exclusion chromatography (SEC), improving EV purity to ~10⁹ particles/µg protein. This work establishes EVOs as a promising tool for EV research and clinical applications, offering a streamlined approach to EV isolation with enhanced analytical performance.