In this work, three Mg–Zn–Y–Ca alloys reinforced by icosahedral quasicrystal phase through trace Y addition were extruded at a low temperature of 503 K. With increasing the contents of Zn and Y, the grain size of the as-extruded alloy was significantly reduced while both the size and volume fraction of nanosized precipitates were increased. The grain refinement in the Mg–Zn–Y–Ca alloy was related to dynamical recrystallization during extrusion and the pinning effect of nanosized precipitates on the grain boundaries. After extrusion, the yield strength (YS) and ultimate tensile strength (UTS) of the three alloys were significantly increased. The YS of 294.0 MPa, UTS of 337.5 MPa, and elongation of 10.6% were obtained in the case of Mg–2.09Zn–0.26Y–0.12Ca (at.%) alloys. The improvement in the mechanical properties could mainly be due to the grain boundary strengthening and Orowan strengthening. The as-cast alloy exhibited a typical cleavage fracture while the as-extruded alloy possessed a mixture fracture of dimple fracture and cracking along the twinning.

Coincidence site lattice (CSL) grain boundaries (GBs) are believed to be low-energy, resistant to intergranular fracture, as well as to hydrogen embrittlement. Nevertheless, the behavior of CSL-GBs are generally confused with their angular deviations. In the current study, the effect of angular deviation from the perfect $\Sigma 3(111)[1\bar 10]$ GBs in α-iron on the hydrogen diffusion and the susceptibility of the GB to hydrogen embrittlement is investigated through molecular static and dynamics simulations. By utilizing Rice–Wang model, it is shown that the ideal GB shows the highest resistance to decohesion below the hydrogen saturation limit. Finally, the hydrogen diffusivity along the ideal GB is observed to be the highest.

This paper explores thin films of the entropy-stabilized oxide (ESO) composition MgxNixCoxCuxZnxScxO (x ~ 0.167) grown by laser ablation in incremental gas pressures and O2/Ar ratios to modulate particle kinetic energy and plume reactivity. Low pressures supporting high kinetic energy adatoms favor the kinetic stabilization of a single rocksalt phase, while high pressures (low kinetic energy adatoms) result in phase separation. The pressure threshold for phase separation is a function of O2/Ar ratio. These findings suggest large kinetic energies facilitate the assembly and quench of metastable ESO phases that may require immoderate physical or chemical conditions to synthesize using near-equilibrium techniques.

In this work, we present an oxygen-releasing insole to treat diabetic foot ulcers. The insole consists of two layers of polydimethylsiloxane: the top layer has selective laser-machined areas (to tune oxygen permeability) targeting the ulcerated foot region, while the bottom layer provides structural support and incorporates a chamber for oxygen storage. When loaded with a pressure of 150 kPa (average value for standing/walking), the insole is able to release oxygen at a rate of 1.8 mmHg/min/cm2. At lower sitting pressures, the delivery rate persists at 0.092 mmHg/min/cm2, raising the oxygen level to an optimal healing value (50 mmHg) for a 2 × 2 cm2 wound within 150 min.

Si-TiN alloys are attractive for use as negative electrodes in Li-ion cells because of the high conductivity, low electrolyte reactivity, and thermal stability of TiN. Here it is shown that Si-TiN alloys with high Si content can surprisingly be made by simply ball milling Si and Ti powders in N2(g); a reaction not predicted by thermodynamics. This offers a low-cost and simple method of synthesizing these attractive materials. The resulting alloys have smaller grain sizes than Si-TiN made by ball milling Si and TiN directly, giving them high thermal stability and improved cycling characteristics in Li cells.

We review progress studying unique plasmonics in topological insulators (TIs). First, we describe exfoliation and deposition synthesis approaches. TI materials have substantially improved: it is now possible to grow samples with few trivial electrons and controllable doping. We then describe the theory behind the unique behavior of the coupled, 2D Dirac plasmons. While reviewing experimental efforts, we note that Dirac plasmons have been conclusively demonstrated in TIs and they show remarkable properties including long lifetimes, large mode indices, and huge modulation depths. Finally, we describe the opportunities that are present now that high-quality materials can be obtained, including spin and nanoparticle plasmons.

Among the commercially common transparent conducting oxides (TCOs) are fluorine-doped tin oxide (FTO) and indium-doped tin oxide (ITO), neither of which meets all criteria for the optimal TCO. Despite its superior chemical stability and being composed of abundant elements, FTO suffers from high surface roughness compared to ITO. Here, we introduce a path to substantially decrease the surface roughness of FTO, while preserving most of its original advantages, by depositing an SnO2 coating on top of the FTO layer using pulsed laser deposition. Such an enhancement may allow future use of FTO in devices that use now the more expensive, less stable ITO, which contains relatively rare indium.

This research introduces a novel single-step approach to improve the absorbency under load (AUL) of agricultural superabsorbent polymers (SAPs) made of acrylamide. Crosslinked (acrylamide–potassium acrylate–acrylic acid) terpolymers were successfully prepared and modified via a transamidation (amide exchange) reaction. The surface of the polymer particles was treated using polyamine modifiers (i.e., diethylenetriamine and polyethyleneimine) in the presence or absence of AlCl3 as a catalyst. The modification reaction was confirmed via spectral, morphological, and rheological studies. The process variables including time and temperature, the modifier type and amount, and the catalyst concentration were found to affect the polymer swelling properties. The swelling capacity of the control and treated SAPs were determined in deionized water and saline. The AUL in saline, as a key swelling property of SAPs, was also determined. The AUL of the PEI-treated samples (19.82–24.8 g/g) was higher than those of the control (17.7 g/g) and the DETA-treated SAPs (18.3–23.5 g/g). In conclusion, the transamidation effectively improved the AUL of the terpolymer superabsorbents by about 25%.

Effective modification of existing supported catalyst has attracted plenty of interests recently. Herein, we introduced ultrasonication to synthesize the palladium-loaded cobalt-based zeolitic imidazolate framework and compared its properties with those using the conventional method. Remarkably, the ultrasonicated frameworks possess 15.33% higher of Brunauer–Emmett–Teller (BET) surface area and 63.37% higher of t-plot external surface area, respectively, which lead up to 23% rise in the degradation of organic pollutants under optimized conditions. Characterizations clearly revealed the causality between ultrasonication, morphology, and catalytic performance compared with their non-ultrasonicated counterparts which further demonstrates a simple but useful method for the modification of supported catalysts.

The ferroelectricity in fluorite-structure oxides such as hafnia and zirconia has attracted increasing interest since 2011. They have various advantages such as Si-based complementary metal oxide semiconductor-compatibility, matured deposition techniques, a low dielectric constant and the resulting decreased depolarization field, and stronger resistance to hydrogen annealing. However, the wake-up effect, imprint, and insufficient endurance are remaining reliability issues. Therefore, this paper reviews two major aspects: the advantages of fluorite-structure ferroelectrics for memory applications are reviewed from a material's point of view, and the critical issues of wake-up effect and insufficient endurance are examined, and potential solutions are subsequently discussed.

A model-guided design methodology for polymer composite electromagnetic (EM) interference shields is presented. The approach utilizes measurement of intrinsic complex EM parameters, predictive modeling of absorbing geometries in the COMSOL environment, and subsequent fabrication using 3D printing and compression molding. The viability of the first two steps in the approach was confirmed using a commercially available conductive nano-filled polymer composite filament, as well as a model system from the literature. Initial results suggest that the addition of periodically placed air-filled pores within the conductive polymer composite can lead to lower reflection loss and higher absorption bandwidths.

Aluminum gallium nitride (AlGaN) metal–semiconductor–metal photodetectors were successfully fabricated with different contact materials and structures and were tested with ultrafast lasers. The experimental results were compared with the finite element simulations based on APSYS and showed consistent trend with respect to the device I–V properties and response behaviors. Persistent photoconductivity (PPC) was observed for devices with both gold and aluminum contacts and various structures, and the decay time can be longer than 10 ms. The response time and responsivity were found to be affected by the bias voltage, operating temperature, and incident power. The mechanism behind the long decay time is analyzed from the perspective of the materials properties and factors influencing the decay time are examined. The nature of the metal–semiconductor contact is studied to help understand the PPC effect, and the contact showed ohmic-like behavior.

In this study, varying contents of ultrafine bamboo-char (UFBC) were introduced into PLA/bamboo particle (BP) biocomposites as new reinforcements to improve the mechanical, thermal, and morphological properties of the biocomposites. The new strategy was aiming to realize the synergistic effects of reinforcement and toughening of poly(lactic acid) (PLA) composites through a simple method without surface modification and other additives. The maximum tensile strength, modulus, and elongation at break of 45.20 MPa, 540.50 MPa, and 7.53% were reached at 5.0 wt% UFBC content, which were slightly lower than those of pure PLA. The maximum modulus of elasticity of the ternary biocomposites was 5316.1 MPa at 5.0 wt% UFBC content, which was approximately 2 times higher than the pure PLA. Impact strength reached a maximum value of 38.56 J/m when the UFBC content was 5 wt%, and improved by 376% compared with pure PLA of 7.88 J/m. Meanwhile, compared with the PLA/BP binary composite of 20.50 J/m, it improved 88%. A concrete-like microstructure system was achieved (i.e., cement, sand, and rebar corresponding to PLA, UFBC, and BP, respectively).

The crystallization mechanism and kinetics of Cr2Ge2Te6 (CrGT) films were investigated by differential scanning calorimetry. The average Avrami exponent (na) analysis indicated that CrGT exhibits a growth-dominant crystallization in the range of heating rate (β) of 10–50°C/min. In comparison, Ge2Sb2Te5 (GST) showed a nucleation-dominant crystallization. The na of CrGT was about 3, and was majorly independent of β. The na of GST decreased with an increasing β, which asymptotically approached a value of around 3. The kinetic constant of CrGT was evaluated to be almost the same with that of GST, indicating that CrGT undergoes fast crystallization.

Owing to lack of a definitive correlation between carbon supports and catalytic activity of single-atom Fe-active sites, rational design and preparation of single-atom Fe catalysts have so far been elusive. Herein we designed and prepared one-dimensional core–shell nanostructured single-atom Fe catalysts, in which carbon nanofibers and carbon nanotubes with different crystallinities and electrical conductivities were used as supports to host single-atom Fe-active sites. It was found that the carbon supports with higher electrical conductivity accelerate charge transfer and enhance the oxygen reduction reaction (ORR) activity of single-atom Fe-active sites as well as the ORR durability of the final catalyst.

A commercially pure titanium (CP-Ti) of grade 1 as a hard-to-deform material was processed successfully by ECAP processing up to four passes at room temperature via the core–sheath method using a die with an internal channel angle of 90°. The simulation and analytical calculations demonstrated that imposed back pressure on the core was increased at each pass due to strain hardening of sheath metal (AISI 1015 steel) during deformation which prevented damage accumulation and crack initiation at a high number of passes. The scanning electron microscopy and transmission electron microscopy observations of ECAP-processed Ti revealed a severely deformed microstructure which consisted of a high dislocation density and an average grain size of ∼250 nm. Mechanical properties of four-pass ECAP-processed CP-Ti showed a substantial enhancement of ultimate tensile strength up to 890 MPa associated with a reasonable elongation to failure of 15.3%.

Biofilms can damage implants and are difficult to treat. Here, we assessed the performance of a tripeptide that self-assembles into an antifouling coating over a broad range of shear conditions that are relevant to biomedical applications. Adhesion assays were performed using a parallel plate flow chamber. The results show that the coating can reduce Escherichia coli adhesion up to 70% when compared with glass. At a shear rate of 15/s, typical for urinary catheters, the coating reduced the adhesion by more than 50%. These findings suggest critical features that should be considered when developing surfaces for biomedical purposes.