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Short-range ordering (SRO) in multi-principal element alloys influences material properties such as strength and corrosion. While some degree of SRO is expected at equilibrium, predicting the kinetics of its formation is challenging. We present a simplified isothermal concentration-wave (CW) model to estimate an effective relaxation time of SRO formation. Estimates from the CW model agree to within a factor of five with relaxation times obtained from kinetic Monte Carlo (kMC) simulations when above the highest ordering instability temperature. The advantage of the CW model is that it only requires mobility and thermodynamic parameters, which are readily obtained from alloy mobility databases and Metropolis Monte Carlo simulations, respectively. The simple parameterization of the CW model and its analytical nature makes it an attractive tool for the design of processing conditions to promote or suppress SRO in multicomponent alloys.

Structural materials used in nuclear reactor environments are subjected to coupled extremes such as high temperature, irradiation, and corrosion which act in concert to degrade their functional performance. Connecting alloy microstructure such as grain boundaries, and accumulating point defects with corrosion attack and pore morphology is critical to understanding underlying mechanisms. We uncover the compositional variations and morphology at multiple length scales in corrosion-damaged Ni-Cr alloy after exposure to oxidants in molten fluoride salts. A complex network of dense corrosion pores is detected by surface-level SEM observations. The corrosion pores take on a 1-dimensional morphology and are enriched with Ni and depleted of Cr 1–5 µm from the pore surface. STEM-EDS and 4D-STEM strain maps acquired simultaneously highlight the local variations in composition and structure of a ≤ 200 nm Cr-rich layer identified from a cross-section taken at the bottom of an isolated corrosion pore between the Ni-Cr alloy matrix and the embedded salt. However, the absence of an observed interface between the Ni-Cr alloy matrix and the FCC-structured Cr-rich layer suggests that Cr plating from the salt did not transpire. These findings support a proposed Cr lattice diffusion mechanism rather than Cr-precipitation from the salt to accommodate temperature transient conditions during sample cooling. Through the development of a 1D phase field model, these results are rationalized by formation energies for the Ni- and Cr-oxidation into the molten salt. This study reveals the locally altered microstructure caused by high temperature corrosion in non-steady-state molten salt nuclear reactor environments.

Metal halide perovskites (MHPs) are low-temperature processable hybrid semiconductor materials with exceptional performances that are revolutionizing the field of optoelectronic devices. Despite their great potential, commercial deployment is hindered by MHPs lack of stability and durability, mainly attributed to ion migration and chemical interactions with the electrodes. To address these issues, 2D layered MHPs are investigated as possible device interlayers or active material substitutes. Here, the 2D perovskite (PEA)2PbBr4 is considered that is recently discussed as promising candidate for X-ray direct detection. While the increased resilience of (PEA)2PbBr4 radiation detectors has already been reported, the physical mechanisms responsible for such improvement compared to 3D perovskites are not still fully understood. To unravel the charge transport process in (PEA)2PbBr4 crystals thought to underly the device better performance, an investigation technique is adapted previously used on highly resistive inorganic semiconductors, called photo induced current transient spectroscopy (PICTS). It is demonstrated that PICTS can reliably detect three trap states (T1, T2, and T3), and that their evolution upon X-ray exposure can explain (PEA)2PbBr4 superior radiation tolerance and reduced aging effects. Overall, the results provide essential insights into the electrical characteristics of 2D perovskites and their potential application as reliable direct X-ray detectors.

The advance of printed electronics is significantly bolstered by the development of liquid-state electronics that overcome the inherent limitations in flexibility and reconfigurability of solid-state electronics. By integrating the biocompatibility and conductivity of sulfonated polyaniline (S-PANI) and phytic acid (PA) with the reconfigurability of structured liquids, highly conductive all-liquid threads are developed. The dense packing and overlap of PA/S-PANI complexes at an oil/water interface promotes in-plane electron transport, and standard four-point probe measurements of PA/S-PANI interfacial assemblies demonstrate enhanced electrical properties. Notably, the rapid jetting of the ink phase into the matrix phase allows for liquid threads to be printed, enabling the fabrication of large-scale, conductive pathways between two electrodes and liquid circuits. Upon mechanical cleavage of the liquid wires, circuits can be broken, but will easily self-repair using an electric field, making this motif useful in the design of switches as well as restoring conductive pathways in series or in parallel. The demonstrated flexibility and reconfigurability these PA/S-PANI wires possess hold significant promise for their practical use in the design of flexible and adaptive bioelectronics that can be repaired on demand, signifying a transformative step in the evolution of liquid electronic materials.

The atomic-level structure of interfaces between Pt and a transition form of Al2O3 were studied using a combination of electron microscopy and first principles calculations. A model system of Pt nanoprecipitates in Al2O3 were formed in sapphire wafers via high-energy ion implantation of Pt followed by thermal annealing at 1000 °C in air. The Pt nanoparticles took the form of tetrahedra and truncated tetrahedra primarily bound by {111}Pt facets. The high prevalence of these facets motivated the development of density functional theory (DFT) based models of (111)Pt interfaces with six different chemical terminations of (2¯01) θ-alumina. The atomic-level structure of the Pt/Al2O3 interfaces was characterized with aberration-corrected scanning transmission electron microscopy (STEM) and the experimental images were compared to STEM image simulations of the DFT models. The model interface with Pt bonded to oxygen-terminated θ-Al2O3, with the Pt located on top of the O and with an underlying layer of octahedral Al, provided the best match to the experimental images. This interfacial termination is also the most stable for the thermal annealing conditions used based on thermodynamic calculations of the interfacial energy as a function of temperature and oxygen partial pressure. This experimentally verified model provides a basis for improving models of Pt/γ-alumina interfaces.

The design principles of acceptor1–acceptor2 copolymers featuring alternating diketopyrrolopyrrole (DPP) and thienopyrrolodione (TPD) moieties are investigated. The investigated series of polymers is obtained by varying the aromatic linker between the two acceptor motifs between thiophene, thiazole, pyridine, and benzene. High electron affinities between 3.96 and 4.42 eV, facilitated by the synergy of the acceptor motifs are determined with optical gaps between 1.37 and 2.02 eV. Grazing incidence wide-angle X-ray scattering studies reveal a range of film morphologies after thermal annealing, including face-on, end-on and superstructure edge-on-like crystallites. Conversely, all materials form thin edge-on layers on the polymer–air interface, as demonstrated by multi-elemental near-edge X-ray absorption fine-structure spectroscopy. The benefit of the electron-deficient linkers thiazole and pyridine is evident: In organic field effect transistors, electron mobilities of up to 4.6 × 10−2 cm2 V−1 s−1 are obtained with outstanding on/off current ratios of 5 × 105, facilitated by the absence of detectable hole transport in these materials. Viability for all-polymer solar cells is assessed in active layer blends with the donor polymer PM6, yielding a maximum average power conversion efficiency of 4.8% and an open circuit voltage above 1 V.

A low-carbon micro-alloyed (LCMA) steel with a body-centered cubic (bcc) crystal structure suitable for extremely low temperatures was developed by overcoming the intrinsic ductile-to-brittle transition in bcc alloys at cryogenic temperatures. The excellent cryogenic-to-ambient impact toughness in the LCMA rolled plate results from its heterogeneous microstructure, which gradually changes from bamboo-like ultrafine grains (∼ 1.1 μm) on the surface to relatively equiaxed coarse grains in the core (∼ 3.4 μm), accompanied by a distinct texture gradient variation. The heterostructured LCMA steel displays a cryogenic impact toughness of ∼200 J/cm2 at 77 K, which is 24 times higher than the coarse-grained LCMA steel. Such high impact toughness of heterostructured LCMA arises from the coordinated deformation mechanisms over different length-scales coupled with delamination toughening. At 77 K, the heterostructured steel plate deforms by forming cellular sub-structures at the core to the surface, which refines the microstructure and promotes hetero-deformation induced (HDI) hardening to improve intrinsic toughening. Moreover, the subsequent delamination process induces extrinsic toughening by shielding and blunting the cracks, with the local plane-stress conditions induced by delamination promoting ductile fracture of the coarse grains in the core regions. This low alloy steel with its heterogeneous microstructure exhibits extraordinary impact toughness at cryogenic temperatures highlights the possibility of materials design strategies for sustainable development.

The properties and microstructure of Type 304L stainless steel produced by two additive manufacturing (AM) methods—directed energy deposition (DED) and powder bed fusion (PBF)—are evaluated and compared. Localized heating and steep temperature gradients of AM processes lead to significant residual stress and distinctive microstructures, which may be process-specific and influence mechanical behavior. Test data show that materials produced by DED and PDF have small differences in tensile strengths but clear differences in residual stress and microstructural features. Measured fatigue crack growth rates (FCGRs) for cracks propagating parallel to and perpendicular to the build directions differ between the two AM materials. To separate the influences of residual stress and microstructure, K-control test procedures with decreasing and constant stress intensity factor ranges are used to measure FCGRs in the near-threshold regime (crack growth rates ≤ 1 × 10−8 m/cycle). Residual stress is quantified by the residual stress intensity factor, Kres, measured by the online crack compliance method. Correcting the FCGR data for differences in Kres brings results for specimens of the two AM materials into agreement with each other and with results for wrought specimens, when the latter are corrected for crack closure. Differences in microstructure and tensile strength have an insignificant influence on FCGRs in these tests.

Stretchable electrodes are an essential component in soft actuator systems. In particular, Joule heating electrodes (JHEs) are required for thermal actuation systems. A highly stretchable, patternable, and low-voltage operating JHE based on hybrid layers of silver nanowires (AgNWs) and carbon nanotubes (CNTs) is reported. The conductive layers were applied on a locally pre-strained bistable electroactive polymer (BSEP) membrane to form a wrinkled conductive surface with a low resistance of 300 Ω/sq, and subsequently patterned to a serpentine trace by laser engraving. The resistance of the resulting electrode remains nearly unchanged up to ~80-90% area strain. By applying a voltage of 7 - 9 V to the electrode, the temperature of the BSEP membrane increased to more than 60 °C, well above the polymer's phase transition temperature of 46 °C, thereby lowering its modulus by a factor of 103. An electronic Braille device based on the JHEs on a BSEP membrane was assembled with a diaphragm chamber. The electrode was patterned into 3 × 2 individually addressable pixels according to the standard U.S. Braille cell format. Through Joule heating of the pixels and local expansion of the BSEP membrane using a small pneumatic pressure, the pixels deformed out of the plane by over 0.5 mm to display specific Braille letters. The Braille content can be refreshed for 20,000 cycles at the same operating voltage.

Mollusk shells protect the animals that form and inhabit them. They are composites of minerals and organics, with diverse mesostructures, including nacre, prismatic calcite, crossed-lamellar aragonite, and foliated calcite. Twins, that is, crystals mirror symmetric with respect to their coherent interface, occurring as formation or deformation twins, are observed in all mollusk shell mesostructures but never within calcite prisms. Here, nanotwins and microwins within single calcite prisms are observed in different shells. Using Polarization-dependent Imaging Contrast (PIC) mapping with 20–60 nm resolution, twins are observed to be 0.2–3 µm thick layers of differently oriented and colored crystals with respect to the main prism crystal. Multiple twins are interspersed with the prism crystal, parallel to one another, and similarly oriented. When comparing images of calcite prisms and twins obtained by PIC mapping and by Electron Back-Scattered Diffraction (EBSD), the images correspond precisely. All twins are e-twin types, with 127° angular distance between c-axes. E-twins are the most common deformation twins in geologic calcite, as also observed here in Carrara marble. Location of all twins near the outer surface of all shells and e-twin type both suggest that twins within calcite prisms in mollusk shells result from deformation twinning.

Ion implantation is widely used for doping semiconductors or electroceramic materials and probing material behaviors in extreme radiation environments. However, implanted ions can induce compressive stresses into the host material, which can induce plasticity and mesoscopic deformation. However, these phenomena have almost exclusively been observed in brittle ionic and/or covalently bonded materials. Here, we present transmission electron microscopy observations of unusual implantation-induced plasticity in two metallic alloys. First, Fe2+ ions induce dislocation plasticity below the implanted layer in a model Fe-P alloy. Next, He+ ions form pressurized cavities which activate the fcc-to-hcp strain-induced martensitic transformation in Alloy 625. In both cases, the plasticity can be explained by a combination of implanted ions being incorporated into the lattice and the creation of irradiation defects. These findings have significant implications for mechanical testing of ion-implanted layers, while also opening pathways for using ion implantation to tune stress distributions in metallic alloys.

The tensile creep behavior of a vacuum arc-melted Nb45Ta25Ti15Hf15 refractory high entropy alloy was investigated over a constant true stress range of 50–300 MPa at a temperature of 1173 K. Creep tests were carried out in both high vacuum (5 × 10−6 torr) and ultrahigh purity Ar gas to examine the environmental effect. The samples tested in vacuum exhibited power law behavior with a stress exponent of 4.1 and exceptional tensile creep ductility, whereas those tested in Ar suffered significant embrittlement due to HfO2 formation at grain boundaries, which was exacerbated at low applied stresses where extended exposure to residual O2 gas resulted in more extensive brittle intergranular fracture. Phase decomposition occurred after long-term thermal exposure, where a second Hf-rich body-centered cubic phase formed predominantly at grain boundaries but did not cause embrittlement. Compared to the equiatomic TaNbHfZrTi (Senkov alloy) and face-centered cubic multiple-principal element alloys, Nb45Ta25Ti15Hf15 has superior creep resistance, especially at high applied stresses, while maintaining excellent creep ductility. Transmission electron microscopy revealed that creep deformation in Nb45Ta25Ti15Hf15 at 1173 K is controlled by cross-kink collisions from screw dislocations that results in dipole drag at lower strain rates and jog drag at higher strain rates.

Relaxor ferroelectric polymers exhibiting a giant electrocaloric effect (ECE) can potentially be used to create next-generation solid-state coolers. Under an electric field, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer goes through a large dipolar entropy change producing a high adiabatic temperature change (ΔTECE). This work resolves the molecular origins of the large entropy change behind the electric field-induced dipole switching. A Fourier transform infrared spectroscopy equipped with a high voltage source is used to operandoly observe the characteristic molecular vibrational modes. A short-range trans (T) conformation of the CF2-CH2 dyads interrupted by a gauche (G) conformation, e.g., TTTG in the terpolymer chain, undergoes a dynamic transformation that leads to a corresponding ΔTECE whenever an electric field is applied. The molecular dynamics simulation also proves that the energy barrier that the transformation from TTTGs into a long T sequence overcomes is smaller than that for all other conformations. A mixed solvent system is used to obtain T3G-enriched terpolymer films exhibiting a 4.02 K ΔTECE at 60 MVm−1 and these films are employed to manufacture a 2-layer-cascaded cooling device that achieves a 6.7 K temperature lift, the highest reported value for a 2-layer cascaded device made of fluoropolymers.

Abstract: Exosomes derived from mesenchymal stem cells are an active area of research due to their therapeutic potential in treating osteoporosis. To further harness their therapeutic performance in modulating bone resorption, equipped exosomes with osteoclast‐targeting moieties on their surface as well as chemokine receptor antagonists blocking osteoclast recruitment. Phosphatidylserine (PS), a membrane lipid exerting immunosuppressive and phagocytic signals, is incorporated in the membrane of exosome mimetics (EMs) to achieve a marked affinity for osteoclast precursors and potential anti‐resorptive effects. This is also aimed to tackle a CXCL9‐CXCR3 ligand‐receptor axis, a critical signaling axis in regulating osteoclast precursor recruitment and differentiation at bone resorption sites, by encapsulating a chemical antagonist of CXCR3, AMG487, in the PS‐incorporated EMs (PS‐EMs). The osteoclast‐targeting PS‐EMs loaded with AMG487 effectively protected against bone loss in an ovariectomized mouse model. These findings demonstrate the great promise of PS‐EMs as anti‐resorptive nanotherapies for alleviating osteoporosis.

Identifying next-generation batteries with multivalent ions, such as Ca2+ is an active area of research to meet the increasing demand for large-scale, renewable energy storage solutions. Despite the promise of higher energy densities with multivalent batteries, one of their main challenges is addressing the sluggish kinetics in cathodes that arise from stronger electrostatic interactions between the multivalent ion and host lattice. In this paper, zircons are theoretically and experimentally evaluated as Ca cathodes. A migration barrier as low as 113 meV is computationally found in YVO4, which is the lowest Ca2+ barrier reported to date. Low barriers are confirmed across 18 zircon compositions, which are related to the low coordination change and reduced interstitial site preference of Ca2+ along the diffusion pathway. Among the four materials (BiVO4, YVO4, EuCrO4, and YCrO4) that were synthesized, characterized, and electrochemically cycled, the highest initial capacity of 81 mA h/g and the most reversible capacity of 65 mA h/g were achieved in YVO4 and BiVO4, respectively. Despite the facile migration of multivalent ions in zircons, density functional theory predictions of the unstable, discharged structures at higher Ca2+ concentrations (Cax>0.25ABO4), the low dimensionality of the migration pathway, and the defect analysis of the B site atom can rationalize the limited intercalation observed upon electrochemical cycling.

Four different high-entropy spinel oxide ferrite (HESO) electrode materials containing 5-6 distinct metals were synthesized by a simple, rapid combustion synthesis process and evaluated as conversion anode materials in lithium half-cells. All showed markedly superior electrochemical performance compared to conventional spinel ferrites such as Fe3O4 and MgFe2O4, having capacities that could be maintained above 600 mAh g-1 for 150 cycles, in most cases. X-ray absorption spectroscopy (XAS) results on pristine, discharged, and charged electrodes show that Fe, Co, Ni, and Cu are reduced to the elemental state during the first discharge (lithiation), while Mn is only slightly reduced. Upon recharge (delithiation), Fe is reoxidized to an average oxidation state of about 2.6+, while Co, Ni, and Cu are not reoxidized. The ability of Fe to be oxidized past 2+ accounts for the high capacities observed in these materials, while the presence of metallic elements after the initial lithiation provides an electronically conductive network that aids in charge transfer.

Colloid science has classically concerned itself with the investigation of the properties of dispersed phases in a bulk medium. This has led to the development of a rich amount of chemistry, physics, and engineering that have facilitated the evolution and maturation of this field. One of the many developments made over the last 30 years is the introduction of particles that are heterogeneous in chemistry and shape. These heterogeneities can introduce behaviors that are not achievable in homogeneous systems and that are specific to the type and class of nonuniformity. This has led to the development of numerous technologies, two of which are Janus micromotors and solid surfactants. This review aims to familiarize the reader with the field of heterogeneous particles. We begin with an overview of various synthetic methods to produce colloidal particles that are heterogeneous in chemistry and shape. We then discuss their use as solid surfactants and autonomous micromotors. We then close by summarizing and providing a future perspective on the field.

We present a study directly measuring the electron‐beam‐induced plasticity of amorphous Al2O3 coatings. Core–shell nanostructures are employed as small‐scale model systems for two‐dimensional coatings made by atomic layer deposition (ALD). Copper nanowires (NWs) are used as substrates for ALD deposition, representing a model system for interconnects commonly found in integrated circuits. Experiments are performed in situ in a transmission electron microscope (TEM) and further analyzed with electron energy loss spectroscopy (EELS). Our in situ TEM tensile experiments reveal the highly plastic behavior of the ALD shell, which withstands a maximum strain of 188%. Comparable samples under beam‐off conditions show a brittle fracture, which underlines the effect of electron irradiation. The electron‐beam‐activated bond switching within the amorphous network enables compensation of the applied tensile strain, leading to viscous flow. By incorporating an intermediate nanocrystalline layer within the Al2O3 shell, the plasticity is suppressed and brittle fracture occurs. This work directly demonstrates the tuning of mechanical properties in amorphous ALD structures through electron irradiation.

All solid-state batteries (SSBs) are considered the most promising path to enabling higher energy-density portable energy, while concurrently improving safety as compared to current liquid electrolyte solutions. However, the desire for high energy necessitates the choice of high-voltage cathodes, such as nickel-rich layered oxides, where degradation phenomena related to oxygen loss and structural densification at the cathode surface are known to significantly compromise the cycle and thermal stability. In this work, we show, for the first time, that even in an SSB, and when protected by an intact amorphous coating, the LiNi0.5Mn0.3Co0.2O2 (NMC532) surface transforms from a layered structure into a rocksalt-like structure after electrochemical cycling. The transformation of the surface structure of the Li3B11O18 (LBO)-coated NMC532 cathode in a thiophosphate-based solid-state cell is characterized by high-resolution complementary electron microscopy techniques and electron energy loss spectroscopy. Ab initio molecular dynamics corroborate facile transport of O2- in the LBO coating and in other typical coating materials. This work identifies that oxygen loss remains a formidable challenge and barrier to long-cycle life high-energy storage, even in SSBs with durable, amorphous cathode coatings, and directs attention to considering oxygen permeability as an important new design criteria for coating materials.

It has been shown both theoretically and experimentally that amphiphilic Janus particles are the most effective solid surfactants to stabilize interfaces. In most cases, the Janus particles investigated have uniform morphologies with Janus boundaries dividing the particle into halves. However, there are many examples of Janus particles where the hydrophilic and hydrophobic domains are not equally distributed. The effects of this uneven domain distribution on the mechanism and kinetics of Janus particle assembly, and final equilibrium state are not well-understood. Dynamic pendant drop tensiometry offers a means to probe both the equilibrium assembly and the kinetics and mechanism of assembly. Here, the interfacial kinetics and assembly of spherical anisotropic Janus particles are investigated using dynamic pendant drop tensiometry. Systematic studies quantifying the time-dependent interfacial behavior as a function of Janus particle morphology, chemical composition, particle concentration, and NaOH and HCl concentration are performed. These studies shed light on the assembly mechanism of more complex Janus particle morphologies and highlight their effectiveness as interface stabilizers.

Organophosphate esters (OPEs) are a class of chemicals with a long history of use as plasticizers and flame retardants. (1,2) In the latter context, they have recently become more common, [...]

We used data-driven methods to understand the formation of impurity phases in BiFeO3 thin-film synthesis through the sol-gel technique. Using a high-quality dataset of 331 synthesis procedures and outcomes extracted manually from 177 scientific articles, we trained decision tree models that reinforce important experimental heuristics for the avoidance of phase impurities but ultimately show limited predictive capability. We find that several important synthesis features, identified by our model, are often not reported in the literature. To test our ability to correctly impute missing synthesis parameters, we attempted to reproduce nine syntheses from the literature with varying degrees of "missingness". We demonstrate how a text-mined dataset can be made useful by informing new controlled experiments and forming a better understanding for impurity phase formation in this complex oxide system.

Fast scintillators with a spectroscopic gamma response are essential in nuclear security and medical imaging. However, few individual scintillation materials exhibit both fast scintillation decay and high photopeak energy resolution. We report a nanocomposite scintillator comprising 40 wt % of hafnium oxide nanoparticles uniformly dispersed in a luminescent plastic matrix. The nanoparticles have an average diameter of 4.2 nm and are covalently attached to the polymer matrix to prevent agglomeration and thus achieve high optical transparency across nanocomposite monoliths up to 8.5 mm thick. The measured transmittance is around 80% across the emission range. Gamma pulse scintillation has a fast decay time constant of 2.5 ns and high light output of 8000-9000 photons/MeV. The gamma scintillation shows energy proportionality from 32 to 1275 keV. A 1.93 cm3 nanocomposite produces photopeaks at 32 and 662 keV for 137Cs and at 511 and 1275 keV for 22Na. The photopeak energy resolution at 662 keV is 7.2-9.1%.

We report a synthesis of WSe2 nanocrystals in which the number of layers is controlled by varying the precursor concentration. By altering the ratios and concentrations of W(CO)6 and Ph2Se2 in trioctylphosphine oxide, we show that high [Se] and large Se/W ratios lead to an increased number of layers per nanocrystal. As the number of layers per nanocrystal is increased, the nanocrystal ensembles show less phase-conversion from the metastable 2M phase to the thermodynamically favored 2H phase. Density functional theory calculations indicate that the interlayer binding energy increases with the number of layers, indicating that the stronger interlayer interactions in multilayered nanocrystals may increase the energy barrier to phase-conversion. The results presented herein provide insights for directing phase-conversion in solution-phase syntheses of transition metal dichalcogenides.

Local lattice distortions (LLD) and structural stability of body-centered cubic (bcc) Nb–Ta–Ti–Hf high-entropy alloys (HEAs) are studied as functions of composition employing ab initio density-functional theory calculations, with specific focus on the role of the relative concentrations of group IV (Ti and Hf) versus group V (Nb and Ta) elements. Calculated results are presented as a function of composition x in NbxTa0.25Ti(0.75−x)/2Hf(0.75−x)/2 alloys, for elastic moduli, phonon spectral functions, LLD and structural energy differences for the bcc and competing hexagonal close-packed (hcp) and ω phases. The results highlight the important role of group V elements and LLD in stabilizing the bcc structure. They further reveal how composition x can be tuned to alter both the magnitude of the LLD and structural energy differences. Specifically, the magnitude of the structural energy differences, and elastic and dynamic stability of the bcc phase, are enhanced with increasing x, while the LLD increase in magnitude as this concentration is decreased. The results also show evidence of correlated LLD at lower values of x, reflecting local structural distortions towards the ω phase, but not hcp. The degree of ω-collapse is nevertheless partial i.e., transformation towards this phase is not observed to be complete due to the presence of Ta and Nb. At lower values of x we further find an energy landscape characterized by multiple, nearly degenerate local energy minima for different values of the LLD.

Soft actuators with unique mechanics have gained significant interests for unique capabilities and versatile applications. However, their actuation mechanisms (usually driven by light, heat, or chemical reactions) result in long actuation times. Reported magnetically actuated soft actuators can produce rapid and precise motions, yet their complex manufacturing processes may constrain their range of applications. Here, the “bone-in-flesh” is proposed that constructs combining rigid magnetic structures encapsulated within soft polymers to create untethered magnetic soft actuators. This approach enables these soft, impact-resistant, agile actuators with a significantly simplified fabrication process. As demonstration examples, multiple soft actuators are fabricated and tested, including actuators for auxetic properties, 2D–3D transformations, and multi-stable states. As such, this work offers a promising solution to challenges associated with soft actuators to potentially expand their applications in various domains.

Abstract: Ferroelectric field effect transistors (FeFETs), characterized by their low power consumption and polarization effect, can be employed in photodetectors based on 2D materials. In this paper, a MoS2 phototransistor with epitaxial ferroelectric (Hf0.5Zr0.5)O2 (HZO) is reported as a gate dielectric layer. Gate‐dielectric‐polarization‐dependent ambipolar behavior is observed in the FET, and relatively low power consumption and hysteresis‐free loop are achieved in the FeFET. The anomalous negative photoconductivity (NPC) is observed as well. Possible reasons for such phenomenon are clarified including the photogating effect originating from the interface traps and the polarization‐dependent electric‐field control through ferroelectric gating. The high responsivity of −8.44 × 103 A W−1 in the negative photoconductivity as well as the response time of 500 ms are reported. The demonstrated Molybdenum disulfide (MoS2) FeFET photodetectors show great potential in the on‐chip complementary metal‐oxide semiconductor (CMOS)‐compatible circuits for multifunctional devices.

The creation of metal-metal oxide interfaces is an important approach to fine-tuning catalyst properties through strong interfacial interactions. This article presents the work on developing interfaces between Pt and CeOx that improve Pt surface energetics for the hydrogen evolution reaction (HER) within an alkaline electrolyte. The Pt-CeOx interfaces are formed by depositing size-controlled Pt nanoparticles onto a carbon support already coated with ultrathin CeOx nanosheets. This interface structure facilitates substantial electron transfer from Pt to CeOx, resulting in decreased hydrogen binding energies on Pt surfaces, and water dissociation for the HER, as predicted by the density functional theory (DFT) calculations. Electrochemical testing indicates that both Pt specific activity and mass activity are improved by a factor of 2 to 3 following the formation of Pt-CeOx interfaces. This study underscores the significance and potential of harnessing robust interfacial effects to enhance electrocatalytic reactions.

Alloys of tungsten tetraboride (WB4) with the addition of C and Si were prepared by arc-melting of the constituent elements. The phase purity was established by powder X-ray diffraction (PXRD) and surface morphology by scanning electron microscopy (SEM) analysis. Vickers hardness measurements showed hardness enhancement for alloys with a nominal composition of (W0.98Si0.02):11.6B and (W0.95C0.05):11.6B of 52.2 ± 3.0 and 50.5 ± 2.5 GPa, respectively, compared to 41.2 ± 1.4 GPa for pure WB4. (W0.92Zr0.08):11.6B was determined in previous work to have a hardness of 55.9 ± 2.8 GPa. Bulk moduli were calculated following analysis of high-pressure radial diffraction data and were determined to be 329 ± 4 (K0′ = 2) and 390 ± 9 (K0′ = 0.6) GPa for 8 atom % Zr and 5 atom % C-doping, respectively, compared to 326-339 GPa for pure WB4. Computational analysis was used to determine the dopant positions in the crystal structure, and it was found that Zr primarily substitutes W in the 2c position, Si substitutes for the entire B3 trimers, and C inserts in the Bhex-layer. The hardness enhancement in the case of Zr-doping is attributed primarily to extrinsic hardness effects (nanograin morphology), in the case of C─to intrinsic effects (interlayer bond strengthening), and in the intermediate case of Si─to both intrinsic and extrinsic effects (bond strengthening and fine surface morphology).

Layered double hydroxide (LDH) phases that form during cement hydration can incorporate a variety of interlayer anions in their interlayer positions. Here, a range of phases of general formula [MII(1−x)MIII(x)(OH)2][An−]x/n·zH2O were synthesized, where MII = Mg2+ (hydrotalcite) or Ca2+ (AFm), MIII = Al3+ such that [MII/Al] = 2 (Ca and Mg, atomic units) or 3 (Mg only), and A = Cl−, Br−, or I−. All the synthesized phases were characterized to assess their composition, density, and crystal structure. By approach from undersaturation, the solubility data of these compounds was measured at 5, 25, and 60°C. This thermochemical data was used to successfully model their formation using thermodynamic modeling and to infer the fields of stability of these compounds for conditions of relevance to cementitious systems. It is seen that halide-containing hydrotalcite phases strongly compete with hydroxide-containing hydrotalcite, with the latter prevailing at high pH. In contrast, halide-containing AFm compounds are more stable compared with hydroxide-containing AFm compositions.

The objectives of this work are threefold: (1) quantify the effects that certain print parameters have on the mechanical performance of parts produced by Low Force Stereolithography (LFS), (2) demonstrate the relative impact that certain print parameters have on the mechanical performance of LFS parts and (3) propose theoretical parameter schemas to optimize LFS prints. This work presents the mechanical properties of LFS parts with respect to distinct LFS print parameters, namely print orientation (PO), print layer thickness (LT), post-print cure time (CM) and post-print cure temperature (CT) at three (3) levels apiece. To date, LFS has been largely unstudied; however, as a novel approach with unique engineering material availability, it is important to quantify its overall performance. Using D638-22 to analyze this additive method, it was found that the Segment Modulus (SE), Ultimate Strength (US), percent elongation (%e), Poisson's ratio (n) and Toughness (T) all varied greatly across the nine (9) distinct sample types designed for the study. Specifically, SE, US, %e, n and T achieved a minimum/maximum of 331/463 ksi, 4.39/9.07 ksi, 1.20/3.55%, 0.377/.450 and 0.033/.200 ksi, respectively, depending on the parameters chosen. This wide range of property data must be coupled to LFS print parameters if the technology is to be implemented as a viable approach to manufacture end-use or provisional tooling. Furthermore, it is essential to understand the relationship between a given property and a specific parameter. S/N plots were used to quantify both of these relationships. The results indicate that all print parameters influence the mechanical performance of LFS parts. [ABSTRACT FROM AUTHOR]

Liver cancer is one of the aggressive primary tumors as evident by high rate of incidence and mortality. Conventional treatments (e.g. chemotherapy) suffer from various drawbacks including wide drug distribution, low localized drug concentration, and severe off-site toxicity. Therefore, they cannot satisfy the mounting need for safe and efficient cancer therapeutics, and alternative novel strategies are needed. Nano-based drug delivery systems (NDDSs) are among these novel approaches that can improve the overall therapeutic outcomes. NDDSs are designed to encapsulate drug molecules and target them specifically to liver cancer. Thus, NDDSs can selectively deliver therapeutic agents to the tumor cells and avoid distribution to off-target sites which should improve the safety profile of the active agents. Nonetheless, NDDSs should be well designed, in terms of the preparing materials, nanocarriers structure, and the targeting strategy, in order to accomplish these objectives. This review discusses the latest advances of NDDSs for cancer therapy with emphasis on the aforementioned essential design components. The review also entails the challenges associated with the clinical translation of NDDSs, and the future perspectives towards next-generation NDDSs. [Display omitted] • Liver cancer is one of the aggressive primary tumors as evident by its high rate of incidence and mortality. • Nano-based drug delivery systems have shown several advantages over the conventional treatment modalities for liver cancer. • Different materials had been studied as a nanocarrier for cancer management. • Nanocarriers can be classified into two main categories (organic and inorganic) according to the nature of the material used for construction. • Targeting therapeutic molecules to the liver studied to deliver chemotherapy for the treatment of liver cancer. • Various mechanisms that nano-based drug delivery systems rely on to selectively target and accumulate in liver cancer which include Passive Targeting, Stimuli-Responsive Systems, and Active Targeting. [ABSTRACT FROM AUTHOR]

Flexible capacitive pressure sensors have garnered significant attention in research areas such as electronic skin, wearable devices, medical diagnosis, physical health detection, and artificial intelligence due to their advantageous characteristics, including high sensitivity, flexibility, lightness, and easy integration. Over the past few years, the field of flexible capacitive pressure sensors has experienced notable advancements in materials, structural design, fabrication processes, and applications. This review aims to examine the different materials employed for sensor electrodes and dielectric layers, as well as the structural design of these sensors. Additionally, we delve into the diverse fabrication processes and techniques utilised, including electrode and dielectric layer fabrication, as well as weaving technology. Lastly, we explore the various applications of flexible capacitive pressure sensors, encompassing electronic skin, health monitoring device, electronic textiles, and structural health monitoring. [ABSTRACT FROM AUTHOR]

Johnson's approximation is implemented in a finite element code to simulate the electric field dependence of a core–shell microstructure material. We show how the microstructure, based here on a 50:50 volume fraction, influences the measured effective permittivity as a function of applied voltage. Using a Johnson's parameter of β = 1.0 × 1010 Vm5/C3, verified from commercial BaTiO3‐based multilayer ceramic capacitors (MLCC), we show how the microstructure and the difference in core and shell conductivities alter the local fields generated and how this influences the voltage dependence of the effective permittivity. Systems that comprise a conductive core‐like material surrounded by a resistive shell experience little or modest voltage dependence due to the shell material providing shielding to large electric fields within the cores. Conversely, if the core material is more resistive than the shell material, substantial voltage dependence occurs with simulations showing over a 50% decrease in the effective permittivity. These simulations give improved understanding of voltage dependence and provide a method to help guide the design of future materials for MLCCs with improved performance. [ABSTRACT FROM AUTHOR]

In order to meet the requirements of new renewable energy technologies for electrode materials with appropriate structural, electronic, and mechanical properties, first principles calculations were used to study the electrochemical properties and potential applications of B2S3 semiconductor optoelectronic materials with dynamic, mechanical, and thermal stability. The research results indicate that as an anode material, B2S3 monolayer has suitable storage capacity (Li: 227.2 mAh/g; Na: 340.8 mAh/g), ultra-low diffusion barrier (Li: 0.23 eV; Na: 0.14 eV), and low average open circuit voltage (Li: 0.515 eV; Na: 0.162 eV). It has relatively small lattice changes (Li: 2.5%; Na: 2.1%) during charge and discharge processes. Under different concentrations of lithium/sodium ion adsorption, the metal properties of B2S3 monolayer remain unchanged, exhibiting good conductivity and battery stability. This study indicates that B2S3 semiconductor optoelectronic material is an attractive anode candidate material for lithium/sodium ion batteries. The excellent properties of B2S3 monolayer can further explore its application as an anode material for lithium/sodium ion batteries. [ABSTRACT FROM AUTHOR]

Hemp fiber, recognized for its eco-friendliness, wide availability, and biodegradability, stands as a renewable resource with promising applications. To fully harness its potential, it is crucial to study the relationship between chitosan concentration and both the mechanical and thermal properties of hemp fiber. Understanding these effects can provide a direction to improve the properties and functionalities of hemp fiber, which are essential for many applications, including textiles and construction and automotive materials. Chitosan is known to enhance the antimicrobial and adsorption properties of fibers by changing the chemical properties of the fiber surface. However, up to now, a very limited number of studies have focused on the exact effect of chitosan on the mechanical and thermal stability properties of hemp fibers. Here, the effect of treatment with different concentrations of chitosan solutions is investigated to enhance the properties of hemp fibers and the treated hemp fibers are characterized. It is found that chitosan solution treatment can effectively improve the various properties of hemp fibers. The chitosan treatment improved the surface roughness of hemp fibers. The tensile strength and flexibility of hemp fibers were enhanced. The CSHF-1.5% sample exhibited the highest tensile strength of 616.11 MPa and the lowest tensile modulus of 15.61 GPa. The fiber swelling rate increased to 24.73% at a chitosan solution concentration of 1.5%. The results of thermogravimetric analysis and differential scanning calorimetry analysis demonstrated the effectiveness of chitosan solution treatment in enhancing the thermal stability of hemp fibers. These findings propose a promising method for a significant modification of hemp fiber's mechanical and thermal stability. [ABSTRACT FROM AUTHOR]

Quaternary chalcogenide compositions have gained much attention because of their promising potential for various optoelectronic applications. The band structure, density of states, and optical properties of CuZn2InS4 and CuZn2GaS4 for kesterite and stannite structures are studied with the full-potential augmented plane wave method as implemented in the Wien2k code. The total energy in equilibrium is calculated for different possible crystal structures. The phase stability and transitions with p–d orbitals are also analyzed. Moreover, the absorption coefficient, dielectric function, and refractive index of these materials are explored within a broad range of energy. We compare the calculated band gap values with available experimental results. [ABSTRACT FROM AUTHOR]

BACKGROUND: Work itself and occupational health and safety (OHS) have evolved through industrial revolutions and will also continue to evolve in the future. OBJECTIVE: The aim of this qualitative literature review was to examine how the scientific discussion on new and emerging risks (NERs) related to OHS has evolved in recent decades in developed and newly industrialized countries. METHODS: A search of the Scopus database yielded 34 articles published before 2000 and from 2020 onwards. RESULTS: A review of the articles identified NERs themes related to changes in work patterns, changing workforce and growth in some sectors, climate change, new materials or increased use of materials, new technology and technological development, and viruses. In both article collection periods, possible adverse OHS effects discussed included musculoskeletal disorders, exposure to toxic agents, chemical compounds and hazardous materials, increased stress, increased likelihood of errors and accidents, psychosocial problems, mental fatigue, and increases in work-related illnesses and accidents. CONCLUSIONS: The articles published during both periods discussed similar themes. The main differences were regarding specific time-related cases, such as climate change and COVID-19. Based on the findings of this review, points to consider in OHS management and future studies are discussed. [ABSTRACT FROM AUTHOR]

AbstractSpray drying (SD) is a unit operation that efficiently converts solutions or suspensions into solid products in a simple, versatile, and continuous manner. It is widely used across various industries, including food, pharmaceuticals, and chemical materials, for product development. In this study, we used Citespace to examine how SD has been applied in food research over the past decade, highlighting its significant role in the development of food materials. This review focuses on diverse applications of SD in the food industry, particularly the adjustments of parameters to control particle size, morphology, and composition. Despite recent advancements in SD, several challenges persist, such as high energy consumption and the difficulty of optimizing conditions for different types of materials, which underscore the need for further research. Therefore, we explore potential solutions used for simulating process parameters and droplet variations to produce powders with optimized properties. In addition, we discuss various energy-saving strategies aimed at improving the sustainability of SD and broadening its applications. [ABSTRACT FROM AUTHOR]

Recent advancements in 3D tissue engineering and organ‐on‐a‐chip systems have revolutionized biomedical research by providing sophisticated platforms that mimic complex physiological environments. This review explores various techniques in 3D printing, including bioprinting materials, laser‐induced forward transfer, ink‐jet systems, and microextrusion methods, highlighting their roles in fabricating intricate tissue constructs. Physical and biochemical characterization methods for assessing these engineered tissues on microchips are discussed in detail, emphasizing their importance in accurately replicating physiological conditions. The review further delves into the development of multiple organ and single organ‐on‐a‐chip systems. It covers two‐organ, three‐organ, and four‐organ platforms, as well as individual systems such as pancreas‐on‐a‐chip, kidney‐on‐a‐chip, liver‐on‐a‐chip, lung‐on‐a‐chip, blood–brain barrier‐on‐a‐chip, heart‐on‐a‐chip, breast cancer‐on‐a‐chip, gut‐on‐a‐chip, and blood vessels‐on‐a‐chip. Each section addresses the unique challenges and advancements associated with these models, providing insights into their potential applications in drug testing, disease modelling, and personalized medicine. In conclusion, the article discusses current challenges and offers perspectives on future directions in 3D tissue engineering and organ‐on‐a‐chip technology, highlighting the transformative impact of these systems on biomedical research and healthcare. [ABSTRACT FROM AUTHOR]

Objectives: Due to the complexity and importance of oral bone structure, oral bone regeneration materials differ from those used in other parts of the body. To study the research trends and hotspots of oral bone regeneration materials, this paper conducts a bibliometric analysis of related papers from 1991 to 2023 (retrieved on 27 September 2023). Materials and methods: Using bibliometric methods, two visualization metric software, Citespace and VOSviewer, were used to analyze 1217 papers in SCIE, including paper analysis, author analysis, country and institution analysis, keyword analysis, and cited literature analysis. Results: ① The number of papers is generally increasing and gradually stabilizing; ② Buser D is the most influential author, while Jung, Ronald E has the highest number of papers and total citations; ③ The United States has the highest number of papers and citation frequency. The University of Bern and the University of Zurich in Switzerland are not only the institutions with the most papers, but also the institutions with the most collaborations with other institutions. ④ Many research directions have persisted for decades since their inception. The field of oral bone; regeneration materials is constantly developing and improving. In recent years, the research direction in this field may mainly focus on the role of blood cells and proteins in bone regeneration. ⑤ In recent years, the types of cited literature mainly include barrier membranes, alveolar ridge augmentation, bone graft materials, histological examination, and in vivo animal experimental models. Conclusion: The United States and Switzerland have a significant influence in the field of oral bone regeneration materials. The research hotspot in recent years is mainly on tissue engineering materials. However, traditional materials still occupy a large proportion in clinical treatment or research. In addition, the combined use of new and old materials has gradually become one of the research hotspots in this field. [ABSTRACT FROM AUTHOR]

Recently, metal-supported solid oxide fuel cells (MS–SOFCs) have been in the spotlight again for their design, thanks to their inexpensive materials, robustness, resistance to thermal cycling, and benefits of manufacturability. Hydrogen energy electrochemical devices, like MS–SOFCs, have a lot of potential. They are very ideal substitutes for solid oxide fuel cells (SOFCs) that utilize electrolytes or ceramic electrodes as their carrier basis, because of their greater durability, mechanical stability, heat cycle resistance, and rapid startup time. Even though MS–SOFCs have several advantages over conventional ceramic-based SOFCs, researchers are still struggling to perfect them due to issues such as selecting the appropriate metal-based material for the electrodes (anode, electrode) and comprehending how they deteriorate. This limitation might be evaded by optimizing the pore former filling and the diameter of the metallic supports (130–250μm). Optimization methods, such as particle swarm optimization, as well as penetration cycle numbers (1–15), as well as the impacts of fire temperatures (400–900∘C), were investigated to aid in optimizing the catalyst infiltration procedure. The enhanced cell outperformed its original performance by a factor of three, reaching an ideal energy density of 0.9W cm−2 at 700∘C when powered by hydrogen. The improved cells had a 2% degradation rate per 100h at 550∘C, a 4.5% degradation rate at 600∘C, and a 5.5% degradation rate at 700∘C. We used electrochemical impedance spectroscopy and scanning electron microscopy to look at the catalyst’s mass shipping, coarsening, and chromium poisoning. [ABSTRACT FROM AUTHOR]

Research on the sustainable production of building materials has been increasing from time to time. The construction industry is one of the sectors that leads to the depletion of significant amounts of nonrenewable resources, such as minerals. The ecosystem is deteriorated, and carbon dioxide (CO2) emissions are enormous in the environment due to the use of fossil fuel-based materials. The purpose of this paper is to review the use of plant fibers (hereafter NF) for reinforcement in cementitious concrete. Concrete, plant fibers, their chemical nature, and characteristics are highlighted in an overview. The most important issues in NF-concrete compatibility were discussed, which could provide research opportunities. Modification of NFs and the cement matrix are examined as methods for improving compatibility and degradation. Moreover, the properties and longevity of cementitious materials that are reinforced with natural fibers are also examined. Finally, the review emphasizes the significant research gaps and future research prospects identified in the reviewed papers. [ABSTRACT FROM AUTHOR]