Uniform Structure Research Articles

Preparation, Mechanical and Thermal Insulation Properties of Graphene Oxide/Polydopamine/Polyurethane Foam‐Based Tunnel Insulation Liner Material

This article designs a novel tunnel insulation liner material based on polyurethane foam (PUF), aiming to improve the liner material's mechanical properties, hydrophobicity, thermal insulation properties and to reduce the self‐weight of the material. Firstly, PUF is self‐made using a one‐step method, and the optimal parameter combination is optimized through the single‐parameter (SP) method. Secondly, based on the optimal parameter combination of PUF, a new process is employed to prepare polydopamine (PDA)/graphene oxide (GO)/PUF. Compression experiments and contact angle tests are conducted to assess the physical mechanical properties of PDA/GO/PUF. Infrared thermography and combustion experiments are employed to characterize the thermal insulation performance of PDA/GO/PUF. Microscopic mechanisms are explained through thermogravimetric analysis (TG), scanning electron microscopy (SEM), and Fourier‐transform infrared spectroscopy (FTIR). The results show that: the optimal parameter combination of tin(II) bis(2‐ethylhexanoate) (TEH), water (H2O), and toluene‐2,4‐diisocyanate (TDI) content optimized by the SP method is 4 parts, 2.8 parts, and 19 parts. PUF prepared based on the optimal parameter combination exhibits a dense and uniform cell structure with low density. Under cyclic loading, PDA/GO/PUF composite material exhibits excellent mechanical stability and fatigue resistance; the hydrophobicity, thermal insulation, and thermal stability of PDA/GO/PUF are significantly improved compared to PUF.

Novel design of nickel cobalt boride nanosheets-decorated molybdenum disulfide hollow spheres as efficient battery-type materials of hybrid supercapacitors

Transition metal borides (TMBs) with high theoretical capacitances and excellent electronic properties have attracted much attention as a promising active material of supercapacitors (SCs). However, TMB nanoparticles are prone to conduct self-aggregation, which significantly deteriorates the electrochemical performance and structural stability. To address the severe self-aggregation in TMBs and improve the active material utilization, it is imperative to provide a conductive substrate that promotes the dispersion of TMB during growths. In this work, sheet-like nickel cobalt boride (NCB) was grown on molybdenum disulfide (MoS2) hollow spheres (H-MoS2) by using simple template growth and chemical reduction methods. The resultant NCB/H-MoS2-50 was observed with uniform NCB nanosheets structure on the surface of the H-MoS2 and stronger MB bonding. After optimizing the loading amount of H-MoS2, the optimal composite (NCB/H-MoS2-50) modified nickel foam (NF) exhibits a superior specific capacity (1302 C/g) than that of the NCB electrode (957 C/g) at 1 A/g. Excellent rate capability of 84.8% (1104 C/g at 40 A/g) is also achieved by the NCB/H-MoS2-50 electrode. The extraordinary electrochemical performance of NCB/H-MoS2-50 is credited to the unique nanosheet-covered hollow spheres structure for facilitating ion diffusion and versatile charge storage mechanisms from the pseudocapacitive behavior of H-MoS2 and the Faradaic redox behavior of NCB. Furthermore, a hybrid SC is assembled with NCB/H-MoS2-50 and activated carbon (AC) electrodes (NCB/H-MoS2-50//AC), which operates in a potential window up to 1.7 V and delivers a high energy density of 76.8 W h kg−1 at a power density of 850 W kg−1. A distinguished cycling stability of 93.2% over 20,000 cycles is also obtained for NCB/H-MoS2-50//AC. These findings disclose the significant potential of NCB/H-MoS2-50 as a highly performed battery-type material of SCs.

1.3 μm higher order LP11 mode pulses in praseodymium-doped fluoride fiber laser

Abstract This work demonstrated an LP11 mode pulse laser at O-band using praseodymium-doped fluoride fiber as a gain medium. The Q-switched laser was initially generated using antinomy-telluride/polyvinyl-alcohol (Sb2Te3/PVA) thin film, and the LP11 modes were analyzed using a beam profiler. The pulse laser was achieved at a pumped power of 273–303 mW. With the increase in pump power, the pulse repetition rate increased to a maximum of 60.2 kHz, and the pulse width decreased to a minimum of 2.86 μs. The operating wavelength of the Q-switched output was 1303.2 nm. The corresponding pulse energy and peak power also increased with the increase in pump powers to the maximum of 12.12 nJ and 4.24 mW. The higher-order modes were obtained after the fiber was offset between the single-mode fiber and the two-mode fiber (TMF). The TMF output was then connected to the multimode fiber, a collimator, and the scanning-slit optical beam profiler to observe the higher-order modes. A uniform two-lobe structure of higher-order LP11 modes was observed.

Strontium-Modified porous attapulgite composite hydrogel scaffold with advanced angiogenic and osteogenic potential for bone defect repair

Nano-attapulgite (nano-ATP) has shown potential in promoting mesenchymal stem cell (MSC) adhesion, growth and osteogenic gene expression. In this study, we investigated a 3D-bioprinted porous Sr-ATP (strontium-doped nano-ATP)/GelMA/chitosan composite hydrogel scaffold for bone regeneration. The experiment was divided into four groups based on the concentration of Sr-ATP: control (0%), 0.5%, 1.0% and 2.0%. The primary novelty of our research lies in the incorporation of Sr-ATP, which enhances the biological and mechanical properties of scaffolds. Additionally, we utilized a stable Pickering emulsion templating technique combined with 3D printing to fabricate the scaffold, ensuring a uniform and stable porous structure. The biological and mechanical properties of the scaffold were evaluated in vitro, and its potential to promote angiogenesis and osteogenesis was assessed in vivo using cranial defect model. Our results indicate that the scaffold presents a promising solution for bone formation in bone defects, demonstrating significant improvements in both angiogenesis and osteogenesis.

Effect of Ti, Mn and Mo on the microstructure and properties of CoCrFeNi high entropy alloy coatings prepared by laser cladding

CoCrFeNi-based High Entropy Alloys (HEAs) coatings, with additions of Ti, Mn, and Mo, were synthesized using laser cladding (LC). The pure CoCrFeNi HEA had a uniform FCC structure, exhibiting the lowest hardness and wear resistance but good corrosion resistance. The Ti-added HEA had an FCC+Laves+η phase structure, showing increased hardness and wear resistance due to abrasive and mild surface fatigue wear, though with the poorest corrosion resistance. The Mn-added HEA maintained a single FCC structure with coarser grain boundaries, exhibiting lower hardness and reduced wear resistance due to adhesive, abrasive wear, and minor surface fatigue wear, but with the best corrosion resistance.The Mo-added HEA developed a eutectic structure of FCC and σ phases, achieving the highest hardness and wear resistance due to oxidative wear, but showed moderately decreased corrosion resistance. The varying microstructures significantly impacted the coatings' mechanical properties and corrosion behavior, highlighting the critical role of alloying elements in customizing LCed-HEA coatings for specific applications.

Effects of NaCl/KCl ratios on structural and properties changes in soy‐potato protein mixed gel

SummaryTo reduce the sodium salt content in protein gel‐based foods, this study investigated the effects of different Na‐K ratios on the gelation properties and structural changes of soy protein isolate (SPI) and potato protein isolate (PPI) composite gels. The results showed that the composite gel properties were further enhanced with increasing Na‐K ratio in the SPI/PPI gel system. Specifically, when the Na‐K ratio was 1:1, the SPI/PPI composite gel exhibited the highest gel strength, gel elasticity, WHC, storage modulus (G′), and β‐sheet content, whereas the α‐helix content and β‐turn content were the lowest. Scanning electron microscopy images revealed a dense and uniform network structure of the composite gel. The addition of low concentrations of Na+ and K+ improved the network structure and water‐holding capacity of the SPI/PPI gel during the heat‐induced gelation process. However, excessively high Na‐K ratios weakened the gel properties.

Effect of non-covalently bound alkaline amino acids on the structural characterization, microstructure, and rheological properties of whey protein emulsion gel

The objective of this study was to explore the impact of L-arginine (Arg) and L-lysine (Lys) on the structural changes and rheological properties of whey protein isolate (WPI) emulsion gels through the utilization of multi-spectroscopic techniques and rheological analysis. The results indicated that the incorporation of Lys/Arg caused WPI molecules to become unfolded, thus exposing hydrophobic amino acids and altering the microenvironment of aromatic amino acids. Microstructural studies revealed that WPI emulsion gels containing 0.5% Lys or 2% Arg resulted in a more uniform and compact network structure. This phenomenon could be attributed to the capability of Lys/Arg to improve the hydrophobic interactions and hydrogen bonding between molecules during gel formation, ultimately leading to a network structure characterized by excellent rheological properties, textural properties, and water-holding capacity. These findings provide a theoretical for the development of emulsion gels with improved structural and rheological properties.

Cheap talk with two-sided private information

This paper studies how the transmission of information from a biased expert to a decision maker is affected when the latter has access to an unbiased symmetric private signal. The extra information has two distinct effects on the expert's incentives to communicate. First, there is an information effect that allows the decision maker to choose a better action on expectation. This reduces the implicit cost of transmitting coarse messages and hence hampers communication. Second, there is a risk effect that arises because the extra information introduces uncertainty to the expert. For risk averse experts, this effect increases the cost of sending coarse messages and hence favours communication. I show that the information effect dominates the risk effect, and for any symmetric signal structure there are always sufficiently biased experts for which communication is no longer possible in equilibrium. Moreover, for any bias of the expert, no communication is possible if the signal structure is sufficiently precise. For the uniform signal structure I show that communication decreases with the precision of the signal. Finally, I provide non degenerate examples for which the decision maker's private information cannot make up for the loss of communication implying that the welfare of both agents decreases.

Synthesis of Mesoporous Catechin Nanoparticles as Biocompatible Drug-Free Antibacterial Mesoformulation.

While polyphenolic substances stand as excellent antibacterial agents, their antimicrobial properties rely on the auxiliary support of micro-/nanostructures. Despite offering a novel avenue for enhancing polymer performance, controllable fabrication of mesoporous polymeric nanomaterials encounters significant challenges due to intricate intermolecular forces. In this article, mesoporous catechin nanoparticles have been successfully fabricated using a balanced multivariate interaction approach. The harmonization of the water-ethanol ratio and ionic strength effectively balances the forces of hydrogen bonding and π-π stacking, facilitating the controlled assembly of mesostructures. The mesoporous catechin nanoparticles exhibit a uniform spherical structure (∼100 nm), open mesopores with a diameter of ∼15 nm, and a high surface area of ∼106 m2 g-1. While exhibiting a good biocompatibility and negative surface charge, the mesoporous catechins possess outstanding antibacterial ability and function as an antibiotic mesoformulation without the necessity of loading any drugs. This mesoformulation inhibits 50% in vitro Staphylococcus aureus growth with a low concentration of ∼10 μg mL-1 and achieves complete inhibition at ∼25 μg mL-1. In a mouse wound model, accelerated wound healing and complete closure within 6-8 days are achieved. Proteomics of bacteria reveals that the excellent antibacterial property is attributed to the synergetic effect of mesoformulation's mesostructure and the catechin molecule intervening in bacterial metabolism. Overall, this work may pave a novel way for the future exploration of polymer nanomaterials and antibiotic formulations.

Foam Stabilization Process for Nano-Al2O3 and Its Effect on Mechanical Properties of Foamed Concrete.

Foamed concrete is increasingly utilized in engineering due to its light weight, excellent thermal insulation, fire resistance, etc. However, its low strength has always been the most crucial factor limiting its large-scale application. This study introduced an innovative method to enhance the strength of foamed concrete by using nano-Al2O3 (NA) as a foam stabilizer. NA was introduced into a foaming agent containing sodium dodecyl sulfate (SDS) and hydroxypropyl methylcellulose (HPMC) to prepare a highly stable foam. This approach significantly improved the foam stability and the strength of foamed concrete. Its drainage volume, settlement distance, microstructure, and stabilizing action were investigated, along with the strength, microstructure, and hydration products of foamed concrete. The presence of NA effectively reduced the drainage volume and settlement distance of the foam. NA is distributed at the gas-liquid interface and within the liquid film to play a hindering role, increasing the thickness of the liquid film, delaying the liquid discharge rate from the liquid film, and hindering bubble aggregation, thereby enhancing foam stability. Additionally, due to the stabilizing effect of NA on the foam, the precast foam forms a fine and uniform pore structure in the hardened foamed concrete. At 28 d, the compressive strength of FC0 (0% NAs in foam) is 2.18 MPa, while that of FC3 (0.18% NAs in foam) is 3.90 MPa, increased by 79%. The reason for this is that NA promotes the formation of AFt, and its secondary hydration leads to the continuous consumption of Ca(OH)2, resulting in a more complete hydration reaction. This study presents a novel method for significantly improving the performance of foamed concrete by incorporating NA.

ScAlInN/GaN heterostructures grown by molecular beam epitaxy

Rare-earth (RE) elements doped III-nitride semiconductors have garnered attention for their potential in advanced high-frequency and high-power electronic applications. We report on the molecular beam epitaxy of quaternary alloy ScAlInN, which is an encouraging strategy to improve the heterointerface quality when grown at relatively low temperatures. Monocrystalline wurtzite phase and uniform domain structures are achieved in ScAlInN/GaN heterostructures, featuring atomically sharp interface. ScAlInN (the Sc content in the ScAlN fraction is 14%) films with lower In contents (less than 6%) are nearly lattice matched to GaN, exhibiting negligible in-plane strain, which are excellent barrier layer candidates for GaN high electron mobility transistors (HEMTs). Using a 15-nm-thick Sc0.13Al0.83In0.04N as a barrier layer in GaN HEMT, a two-dimensional electron gas density of 4.00 × 1013 cm−2 and a Hall mobility of 928 cm2/V s, with a corresponding sheet resistance of 169 Ω/□, have been achieved. This work underscores the potential of alloy engineering to adjust lattice parameters, bandgap, polarization, interfaces, and strain in emerging RE-III-nitrides, paving the way for their use in next-generation optoelectronic, electronic, acoustic, and ferroelectric applications.

Microstructure evolution in A356 alloy subjected to controlled heat treatment regimes processes

Aluminium–silicon alloys are highly regarded for their lightweight and unique mechanical properties, making them crucial for various industrial applications. Achieving optimal mechanical behavior in Al-Si-based alloys necessitates meticulous control over their microstructure. The research investigated the impacts of heat treatment regimes on the microstructure of A356 hypoeutectic alloys by light optical microscope (OM), scanning electron microscope (SEM), and energy dispersive spectroscope (EDS). The alloy, produced via stir-casting, underwent homogenization at 540 °C/5 h, one-step (200 °C for 0.5–8 h (T1)) and two-step (T2 (200 °C/0.5 h/180 °C/0.5–8 h)), and T2L (200 °C/0.5 h/160 °C/0.5–8 h)) aging processes. The findings revealed significant microstructural changes due to heat treatment. Homogenization reduced the average grain size of eutectic silicon by 20.5%. The T1 treatment increased the grain size and changed the grain morphology with prolonged aging, negatively impacting the mechanical properties. The T2 and T2L treatments resulted in finer, more uniform grain structures. The T2L treatment produced the finest eutectic silicon and the most uniform grain distribution, indicating the superior potential for mechanical performance. Overall, this study underscores the importance of tailored heat treatment regimes to optimize the microstructure and enhance the structural sensitive properties of Al-Si alloys, benefiting automotive and aerospace industries.

Highly efficient lignin depolymerization and enhanced bio-oil upgrading via in-situ hydrogenation: Impact of lignin structure

The inherent structural rigidity of lignin poses a significant challenge to its direct hydrogenation to produce aromatic compounds, requiring harsh reaction conditions. In this study, microwave-assisted hydrothermal liquefication was employed to rapidly generate raw bio-oil under mild conditions, coupled with an in-situ hydrogenation strategy to upgrade its quality. A series of lignin substrates were characterized to establish the relationship between lignin characteristics and aromatic products. Grass lignin can produce low molecular weight bio-oil in high yields (50.4–60.7 %) within 30 min at 180 °C, which is attributed to the abundance of cleavable β-O-4 linkages in its uniform structure. In contrast, softwood lignin with abundant guaiacyl (G) units possessed a robust thermal stability, resulting in a low monomer yield, but a high selectivity to G-type products (97 %). The raw bio-oil was further upgraded through in-situ hydrogenation with Pd catalysts. Low reaction temperatures (60–100 °C) favored the hydrogenation of aromatic aldehydes and ketones to their alcohol products, while high temperatures (100–220 °C) promoted the deep hydrogenation of aromatic side chains to alkyl products. Besides, an upgraded bio-oil with a higher heating value (29.8 MJ/kg) was obtained. Furthermore, the hydrogenation mechanism was investigated through the kinetics of simulated bio-oils. The activation energy follows the order: dimer β-O-4 linkage < monomer aldehyde group < ketone group < CC linkage, which is consistent with the hydrogenation kinetics observed in real lignin bio-oil. Overall, this study highlights the impact of lignin characteristics on subsequent conversion and alsoenhances our understanding of the complex depolymerization/hydrogenation mechanisms during lignin upgrading.

Anthocyanin-rich grape pomace extract encapsulated in protein fibers: Colorimetric profile, in vitro release, thermal resistance, and biological activities

Red wine grape pomace is an important source of bioactive compounds with biological activities of interest. Grape pomace extract can be encapsulated in ultrafine fibers using the electrospinning technique. Encapsulation is used to increase stability and protect the phenolic compounds in the extract. In this study, zein fibers were developed for encapsulation of grape pomace extract (0 %, 5 %, 10 %, and 15 % w/w). The extract was evaluated for colorimetric profile, whereas the ultrafine zein fibers carrying the extract were assessed for morphology, loading capacity, in vitro release profile, thermal and thermogravimetric properties, thermal resistance, hydrophilicity, and antioxidant and antimicrobial activities. The grape pomace extract changed color depending on pH, ranging from pink (pH 1) to yellow (pH 13 and 14). The fibers presented a smooth and uniform structure, with diameters of approximately 450 nm and a loading capacity of up to 82 %. The membranes of ultrafine fibers demonstrated hydrophilic behavior, and the in vitro release profile was dependent on the concentration of the added extract. Furthermore, the fibers were observed thermally protect the encapsulated compounds and maintain their antioxidant and antimicrobial activities. These findings indicate that the produced material has potential applications in the development of active and intelligent packaging for the food industry.

Size effect on tensile bonding strength between new and old concrete

The interface between new and old concrete plays a significant role in reinforced concrete engineering due to its size effect and weak strength. To investigate the size effect of tensile strength in new-to-old concrete, splitting tensile tests and computed tomography (CT) scans on composite specimens were conducted. Specimen size, interface roughness, volume fraction of polyvinyl alcohol fiber and adhesive were considered. The tensile bonding strength initially increases and then decreases with interface roughness and fiber content, while size effect on the strength shows a downward trend before rising. The adhesive notably enhances the tensile bonding strength and weakens its size effect. The interface roughness, polyvinyl alcohol fibers and interface agents influence the size effect by modifying the bonding area, specimen uniformity, and characteristic structure of the interface region. At an interface roughness of 5.5 mm and a polyvinyl alcohol fiber content of 0.5 %, the maximum strength was achieved and the maximum attenuation of size effect occurred. The size effect laws of tensile bonding performance were presented based on the Weibull statistical theory, Bažant energy theory and Carpinteri multi-fractal theory. The experimental values exhibit good consistency with the predictions from the size effect models.

An In Situ Generated Organic/Inorganic Hybrid SEI Layer Enables Li Metal Anodes with Dendrite Suppression Ability, High-Rate Capability, and Long-Life Stability.

High-quality solid electrolyte interphase (SEI) layers can effectively suppress the growth of Li dendrites and improve the cycling stability of lithium metal batteries. Herein, 1-(6-bromohexanoyl)-3-butylurea is used to construct an organic/inorganic hybrid (designated as LiBr-HBU) SEI layer that features a uniform and compact structure. The LiBr-HBU SEI layer exhibits superior electrolyte wettability and air stability as well as strong attachment to Li foils. The LiBr-HBU SEI layer achieves a Li+ conductivity of 2.75 × 10-4 S cm-1, which is ≈50-fold higher than the value measured for a native SEI layer. A Li//Li symmetric cell containing the LiBr-HBU SEI layer exhibits markedly improved cyclability when compared with the cell containing a native SEI layer, especially at a high current density (e.g., cycling life up to 1333h at 15mA cm-2). The LiBr-HBU SEI layer also improves the performance of lithium-sulfur cells, particularly the rate capability (548 mAh g-1 at 10C) and cycling stability (513 mAh g-1 at 0.5C after 500 cycles). The methodology described can be extended to the commercial processing of Li metal anodes as the artificial SEI layer also protects Li metal against corrosion.

Interfacial Zn2+-solvation regulator towards reversible and stable Zn anode

Aqueous zinc-ion batteries (AZIBs) are fundamentally challenged by the instability of the electrode/electrolyte interface, predominantly due to irreversible zinc (Zn) deposition and hydrogen evolution. Particularly, the intricate mechanisms behind the electrochemical discrepancies induced by interfacial Zn2+-solvation and deposition behavior demand comprehensive investigation. Organic molecules endowed with special functional groups (such as hydroxyl, carboxyl, etc.) have the potential to significantly optimize the solvation structure of Zn2+ and regulate the interfacial electric double layer (EDL). By increasing nucleation overpotential and decreasing interfacial free energy, these functional groups facilitate a lower critical nucleation radius, thereby forming an asymptotic nucleation model to promote uniform Zn deposition. Herein, this study presents a pioneering approach by introducing trace amounts of n-butanol as solvation regulators to engineer the homogenized Zn (H-Zn) anode with a uniform and dense structure. The interfacial reaction and structure evolution are explored by in/ex-situ experimental techniques, indicating that the H-Zn anode exhibits dendrite-free growth, no by-products, and weak hydrogen evolution, in sharp contrast to the bare Zn. Consequently, the H-Zn anode achieves a remarkable Zn utilization rate of approximately 20% and simultaneously sustains a prolonged cycle life exceeding 500 h. Moreover, the H-Zn//NH4V4O10 (NVO) full battery showcases exceptional cycle stability, retaining 95.04% capacity retention after 400 cycles at a large current density of 5 A g−1. This study enlightens solvation-regulated additives to develop Zn anode with superior utilization efficiency and extended operational lifespan.

Mechanical response of LPBFed TI64 thickness graded Voronoi lattice structures

The possibility to realize Additively Manufactured functionally graded lattice structure based on Voronoi tessellation enormously increases the possibility in tailoring the stiffness, mechanical properties and energy absorption capacity of the samples. The work presents the design and mechanical characterization of functionally thickness graded Voronoi lattice structures in comparison with constant thickness lattice structures for the evaluation of mechanical performance and energy absorption capacity. Firstly, the design and laser power bed fusion process are detailed. The dimensional deviation between designed models and Ti6Al4V specimens is quantified to assess the samples’ quality. Their mechanical performance is analyzed by quasi-static compression experimental tests, supported by numerical analysis for the evaluation of local stress distributions and deformation modes. The average dimensional deviation between CAD models and fabricated samples is 0.09 mm, likeminded with the literature optimum. The structures exhibit Young Modulus values ranging between 10 MPa and 21 MPa, compatible with biomedical applications. The compressive force for thickness graded structures tends to increase up to densification, while uniform thickness structures present an almost constant value of force in the platform stage. Additionally, the energy storage changes according to the presence of thickness gradient: the larger the thickness gradient, the larger the energy absorption capacity.

Microstructure refinement and wear resistance enhancement of cost-effective Fe50−2xMn30Co10Cr10NixCux (x = 0, 5 at%) high-entropy alloys through cyclic closed-die forging process

Novel low-cost Fe50−2xMn30Co10Cr10NixCux (x = 0, 5 at%) high-entropy alloys (HEAs) were produced by vacuum melting and then processed by the cyclic closed-die forging (CCDF) process. It was found that both the as-homogenized and CCDF-processed specimens primarily consisted of a single face-centered cubic (FCC) structure, and the severe plastic strain through CCDF did not result in phase transformations. The microstructure of the CCDF-processed Fe50Mn30Co10Cr10 alloy after the sixth pass demonstrated a uniform structure with ultrafine grains measuring 285 nm in size, whereas for the CCDF-processed Fe40Mn30Co10Cr10Ni5Cu5 alloy, the grain size was 135 nm, with a relatively uniform distribution. The CCDF-processed Fe50Mn30Co10Cr10 and especially the Fe40Mn30Co10Cr10Ni5Cu5 alloy exhibited significantly higher microhardness compared to the as-homogenized state, with microhardness values being 2.42 and 2.72 times higher, respectively. Furthermore, the wear test results indicated that the CCDF processing effectively increased the wear resistance of the alloys, which was attributed to the changes in morphology and distribution of as-cast dendrites, along with the grain refinement of the matrix phase during CCDF. The CCDF-processed Fe40Mn30Co10Cr10Ni5Cu5 alloy exhibited the lowest wear rate, i.e., (1.2 ± 0.2) × 10–5 mm3.N−1.m−1, whereas that for the Fe50Mn30Co10Cr10 alloy was (2.4 ± 0.1) × 10–5 mm3.N−1.m−1. Analysis of wear surfaces indicated that the wear mechanisms of the as-homogenized HEAs were adhesive wear and abrasive wear with some delamination, while plastic deformation and adhesive wear were significantly reduced in the CCDF-processed specimens, especially in the Fe40Mn30Co10Cr10Ni5Cu5 alloy. These findings suggest that CCDF has the potential to achieve cost-effective nanostructured HEAs and to implement them in engineering applications.

Patterned Gold Nanoparticle Superlattice Film for Wearable Sweat Sensors.

Nanoparticle superlattices are beneficial in terms of providing strong and uniform signals in analysis owing to their closely packed uniform structures. However, nanoparticle superlattices are prone to cracking during physical activities because of stress concentrations, which hinders their detection performance and limits their analytical applications. In this work, template printing methods were used in this study to prepare a patterned gold nanoparticle (AuNP) superlattice film. By adjustment of the size of the AuNP superlattice domain below the critical size of fracture, the mechanical stability of the AuNP superlattice domain is improved. Thus, long-term sustainable high-performance signal output is achieved. The patterned AuNP superlattice film was used to construct a wearable sweat sensor based on surface-enhanced Raman scattering (SERS). The designed sensor showed promise for long-term reliable use in actual scenarios in terms of recommending water replenishment, monitoring hydration states, and tracking the intensity of activity.