The dendrite morphologies of the cast nickel-based superalloy CMSX-4® (CMSX-4® is registered trademarks of the Cannon-Muskegon Corporation) and the austenitic stainless steel HP microalloy have been obtained via an automated serial-sectioning process which allows three-dimensional (3D) microstructural characterization. The dendrite arm spacing, volume fraction of segregation, and fraction of porosity have been determined. This technique not only increases the depth, scope, and level of detailed microstructural characterization but also delivers microstructural data for modeling and simulation.

Melt electrospinning is a facile fabrication technique that can be utilized in the creation of microfibers without the use of solvent and with good control over feature placement. The available thermal energy of the melt electrospinning technique is often only utilized in the formation of the polymer melt but can also be used to thermodynamically drive chemical reactions. In this study, hybrid perovskite microcrystallites are synthesized in the polymer melt and electrospun to form composite microfibers. Unique hybrid perovskite microstructures were studied, elucidating mechanisms of formation at work in the polymer melt.

The goal of this study is to examine whether participation in high school research apprenticeships increases pursuit of degrees and careers in science, and to explore other apprenticeship benefits. Students who participated in a research apprenticeship were surveyed about its influence on their undergraduate, graduate, and professional decisions. A control group who attended the same high schools, had similar grade point averages, and graduated with the apprenticeship participants was also surveyed. It was found that a significantly higher fraction of the apprenticeship group majored in Science, Math, Engineering, and Technology (STEM) fields, pursued careers in STEM disciplines, and found the experience to strategically influence their job performance.

Energy-filtered transmission electron microscopy provides an opportunity to map the nanoscale elemental composition in polymeric systems. Nevertheless, it presents its own set of unique challenges in its application to soft materials. Here, we outline an optimized protocol for elemental mapping in soft materials using sulfur mapping of polymer/fullerene mixtures as an example. Three factors are crucial: (1) focusing at zero-loss, (2) using an objective aperture, and (3) maximizing signal-to-noise and counts for the chosen imaging conditions. Analyzing the corresponding source images, bright field images, and thickness maps can ensure optimum conditions are achieved for elemental mapping of polymers.

Here we report a new type of n-type flexible film with a double-layer structure fabricated by hybridizing an n-type inorganic thermoelectric material, bismuth selenide (Bi2Se3), and an ordinary insulating polymer, poly(vinyl alcohol) (PVA). Flake-shaped Bi2Se3 nanoparticles (Bi2Se3 nanoflakes) modified with/without gold (Au) nanoparticles were distributed in the one side of PVA film with the particular arrangement, and the hybrid film showed a high Seebeck coefficient (−91 µV/K at room temperature) as an n-type flexible material. Our method is expected to be used for the design of flexible functional devices such as flexible thermoelectric modules.

A glucose-reduced, room temperature-synthesized colloidal Cu2O solution (CCS) was used for the first time to detect humic acid (HA), a carcinogen-promoting substance in aqueous solution. The CCS sensor was characterized using standard spectroscopy and microscopy techniques. The sensor evolved as a carboxylic acid-capped peach-pink solution after synthesis. The result of the interaction of the sensor with HA in phosphate buffer solution (pH 7) showed a detection limit of 1.5891 × 10−2 mg/L over a concentration range of 0.00–0.41 mg/L. This finding suggests that the sensor may be useful for monitoring low levels of HA in aqueous environments.

This study compares the investigated water vapor diffusion coefficient in the neat polyurethane (PU) membrane, the silica–PU nanocomposite membrane, and two surface-modified silica–PU nanocomposite membranes. The silane first surface modifier is with an amine functional group known as N-[3-(trimethoxysilyl)propyl]ethylenediamine, while the second one is with an aniline functional group known as N-[3-(trimethoxysilyl)propyl]aniline. The enhancement of water vapor diffusivity values through the polymer nanocomposite is desirable for the membrane air dehumidification application. The diffusivities were calculated via molecular dynamics simulations at the temperature of 298.15 K. The Einstein's relationship known as the mean square displacement method was used to obtain the diffusivity for the membranes. The results showed a significant effect on the diffusivity of water vapor for the surface-modified silica–PU nanocomposite membrane as compared with the neat PU and the unmodified silica–PU nanocomposite membranes. For the amine-modified silica, the diffusion coefficient increased by 80.3% compared with the unmodified silica–PU nanocomposite membrane. On the other hand, the aniline-modified silica outperformed the amine-modified one in terms of the diffusion coefficient by 22.4%.

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.

Ni–Pt polyhedral nanoparticles were synthesized through a thermochemical route by the hot-injection method using Oleylamine (Oam) and Oleic acid (Oac) solvents as simultaneous stabilizing and reducing agents. Several syntheses were performed to study the effect of the hot-injection temperature on nanoparticle size distribution. Results revealed that the injection of precursors in a mixture of Oam and Oac at 180 °C produced paramagnetic nanoparticles with an approximate size of 27 nm; these particles have uniformly defined polyhedral structures and show greater Pt accumulation on the edges and corners. Ni–Pt polyhedral nanoparticles with larger sizes and high polydispersity were obtained as the injection temperature was increased closer to the reduction temperature.

The molybdenum disulfide (MoS2) and indium tin oxide (ITO) interface were studied by atom probe tomography (APT). Raman spectroscopy, scanning electron microscopy, and grazing-incidence x-ray diffraction measurements were performed as complementary characterization. Results confirm that nanowires plated shape with the 〈110〉-orientation are aligned perpendicular to the ITO film with principal reflections at (002), (100), (101), (201), and Raman spectroscopy vibrational modes at E12g at 378 cm−1 and A1g at 407 cm−1 correspond to 2H-MoS2. APT reveals MoS+2, MoS+3 as predominant evaporated molecular ions on the sample, indicating no significant diffusion/segregation of Mo or S species within the ITO layer.

Silver nanowire-based contacts represent one of the major new directions in transparent contacts for opto-electronic devices with the added advantage that they can have Indium-Tin-Oxide-like properties at substantially reduced processing temperatures and without the use of vacuum-based processing. However, nanowires alone often do not adhere well to the substrate or other film interfaces; even after a relatively high-temperature anneal and unencapsulated nanowires show environmental degradation at high temperature and humidity. Here we report on the development of ZnO/Ag-nanowire composites that have sheet resistance below 10 Ω/sq and >90% transmittance from a solution-based process with process temperatures below 200 °C. These films have significant applications potential in photovoltaics and displays.

Heterogeneous magnesium matrix nanocomposites (Hetero-Mg-NCs) exhibited excellent strength–toughness synergy, but their damage behavior and toughness mechanism lacked of investigation. Here, atomic force microscopy was first employed to characterize the microstructure evolution and damage behavior of the Hetero-Mg-NCs after indentation. The heterogeneous structure comprised of pure Mg areas (soft phase) and Mg nanocomposite areas (hard phase) was revealed by the electrostatic force microscopy. Furthermore, the surface morphology and cracks of the deformed area were investigated with high resolution. The results indicated the soft phase undertook most of the deformation and played an important role in capturing and blunting the crack.

First principles density functional theory calculations were conducted to investigate the structures and energetics of polyhedral oligomeric silsesquioxane (POSS) molecules with varying aluminum and alkali (sodium or potassium) concentrations. Notable trends emerge from this study namely, (1) the thermodynamic stability of the substituted POSS molecules is critically dependent on the interplay between size and composition of the POSS structures, and (2) larger POSS structures provide lower central electron density and hence better accommodate the central alkali atom. These observations, when viewed in the context of aluminosilicate based geopolymers, provide fundamental insights into the relations that describe the structure composition interplay of their underlying monomers.

Solution-processed hole contact layers (HCLs) of metal oxide nanoparticle (NP) films improve performance of organic photovoltaics (OPVs), but have thus far required harsh post-deposition thermal or plasma treatments. Here, we describe a general method to synthesize suspensions of ultrasmall (1–2 nm) MoO3, WO3, NiOx, and CoOx NPs in n-butanol. Spin-coated metal oxide NP films with no post-deposition treatment exhibit high work function and ionization energy consistent with the oxidation states of the metal cations. Metal oxide NP HCLs demonstrate performance matching those of reference conventional and inverted OPVs containing PEDOT:PSS and evaporated MoO3.

Nickel thin films were prepared by electroless plating in a foam of electrolyte generated by bubbling nitrogen into a hypophosphite-based electroless plating solution added with surfactants of sulfuric acid monododecyl ester sodium salt and ammonium pentadecafluorooctanoate (APFO). Ferroxyl test revealed that the films deposited in foam had substantially higher corrosion resistance than those deposited in liquid. Even with a film thickness of only 1.5 µm, the fraction of corroded area was as small as 0.002% when the film was deposited in the foam. The notable improvement in the corrosion resistance was made possible by adding APFO as the surfactant.

Composition-dependent microstructure and mechanical properties of ultrafine-grained Al and Al–Mg films fabricated by DC magnetron sputtering with the novel micro-combinatorial technique were studied by transmission electron microscopy, atomic force microscopy, and nanoindentation. It was revealed that these films have extremely high strength, enabling their potential application as protecting layers. Besides the possible practical applications, the results of the present work also confirm the validity of the modified Hall–Petch relationship for the uniform description of the strength of face-centered cubic metals and solid solution having ultrafine-grain size.

In this study, a novel shape memory polymer (SMP), eggshell membrane (ESM), with macroscopic mesh structures and microscopic crosslinked protein fibers, has shown water-stimulated shape recovery characteristics. Our results show that the collagen triple-helical molecular chains and disulfide-rich motifs in the ESM function as net-points retaining essential structures during deformation, while hydrogen bonds play a key role as switch units for shape recovery through water stimulation. We also demonstrate that programmable shape recovery characteristics of ESM can be obtained by modulating the number of net-points. This study may inspire the design of new programmable SMPs.

The theories to describe the rate at which electrochemical reactions proceed do not consider explicitly the dimensionality or the occupancy of the energy levels of nanostructured electrodes. It is shown here that the density of states variation in nanoscale electrochemical systems yield novel modulations in the rate constant and concomitant electrical currents. The proposed models extend the utility of presently used Marcus–Hush–Chidsey kinetics to a larger class of materials and could be used as a test of dimensional character. The new models are applied to explain the experimental variation of the electrochemical rate constant of single-layer graphene.

Natural systems displaying optical properties have for long been an inspiration for new classes of optical constructs. Using the same families of materials employed by Nature in combination with their directed assembly allows access to n-dimensions of control to, ultimately, generate optical systems with multiple coexisting functions. This review provides an overview of lab-made optical systems made of protein and polysaccharide-derived materials found in naturally occurring optical systems. Recent advances in optical biomimicry and bioinspired, polyfunctional optical structures are presented, addressing attributes such as sensing, edible devices, biologically activity, and resorbable optical formats.