In the present work, an efficient route has been further explored to achieve the batch synthesis of inorganic fullerene (IF)-WS2 nanoparticles, and the self-lubricating film is conveniently prepared by coating these nanoparticles on the surface of metal substrates. The as-synthesized IF-WS2 nanoparticles have a closed hollow structure with an average particle size of about 50 nm and are evenly distributed in the self-lubricating film. Further friction tests show that the film has excellent friction properties, with its lowest friction coefficient of approximately 0.008, which can be mainly attributed to the unique hollow cage structure and a smaller particle size of the IF-WS2 nanoparticles.

We report on the synthesis of unique tetragonal nanostructures from porous anodic aluminum oxide that enables geometrical three-dimensional (3D) microdesign of the porous surfaces. Scanning electron microscopy study revealed self-organization of hollow oxide nanostructures into hierarchical arrays. The formation of these structures has a localized nature and is associated with local electrical break-down during hard anodization of aluminum in oxalic acid solution. Moreover, in this communication we propose the mechanism of the nucleation and growth of complex 3D structures from porous anodic alumina.

Methods for the control of molecular deposition and orientation are critical for the development of organic electronic devices. Here, we show the fabrication of ribbons of the optical material polydiacetylene (PDA) using a controlled evaporative self-assembly method. The ability to form these ribbons is highly dependent on both the side groups on the PDA as well as the solvent used in the preparation. Arrays of ribbons of one type of PDA, poly[1,6-di(N-carbazolyl)-2,4-hexadiyne], with widths on the order of 1–2 µm and lengths of 100s of micrometers, could be successfully obtained with good orientation.

We demonstrate that alternating the oxygen partial pressure gradient across a yttria-stabilized zirconia (YSZ) electrolyte membrane prior to solid oxide fuel cell (SOFC) testing with nanoporous Pt electrodes greatly increases (e.g. by >70-fold at 350 °C) peak power density compared with devices without pretreatment. Transiently altering the oxygen activity at the cathode–YSZ interface appears to change the wetting characteristics of the nanoporous Pt, significantly affecting the stability and low-temperature performance of the SOFCs. Image analysis and impedance spectroscopy results suggest that an increase in triple-phase boundary area fraction at the cathode–YSZ interface contributes to the observed effect.

Many studies have been carried out to thoroughly understand the colorization mechanisms of bird feathers. However, most of the methods used so far are time-consuming (in days) and involve rather complicated steps (5 to 12). Here, we report a rapid way of producing ‘PbS bird feathers’; this method is inspired by a hair-dyeing method used in ancient Egypt 4000 years ago. The complete synthesis route comprises only two steps and can be completed within 2 h, with the original morphologies of bird feathers well preserved. This method has potential to be extended to the fast fabrication of other functional sulfides which are too complicated to fabricate otherwise.

To investigate the manipulation of electromagnetic properties of two-dimensional materials, this effort characterizes charge transfer behavior of colloidal COF-5 (covalent organic framework) in the presence of various metal ions. A series of metal chloride compounds was introduced to COF-5 in solution and solid film phases and the interaction of the material with electromagnetic radiation was monitored across the visible region using electronic absorption spectroscopy. Notable changes were observed, quantified, and discussed for copper (II) chloride (CuCl2), chromium (III) chloride (CrCl3), and iron (III) chloride (FeCl3) with COF-5. Ligand-to-metal and metal-to-ligand charge transfer are explored as a possible mechanism for the observed electronic behaviors.

Vertically aligned nitrogen-doped nanocrystalline diamond nanorods are fabricated from nitrogen-doped nanocrystalline diamond films using reactive ion etching in oxygen plasma. These nanorods show enhanced thermionic electron emission (TEE) characteristics, viz., a high current density of 12.0 mA/cm2 and a work function value of 4.5 eV with an applied voltage of 3 V at 923 K. The enhanced TEE characteristics of these nanorods are ascribed to the induction of nanographitic phases at the grain boundaries and the field penetration effect through the local field enhancement from nanorods owing to a high aspect ratio and an excellent field enhancement factor.

Excitation of surface waves on conducting materials provides a near resistance-free interface capable of a material glissade either by plasmon forces or by optical beam tractors. Analogous to an ice hockey rink, as proof-of-principle plasmon-assisted optical traction, or hoovering, of water drops on a gold surface is demonstrated. Changes in the contact angle provide a novel, low-cost nanoscale method of quantifying observable and potentially tunable changes. Variability in thresholds and movement, including jumps, is observed and can be explained by the presence of significant roughness, measured by scanning electron microscopy, with water tension. The demonstration opens a path to directly integrate various optical and plasmonic traction technologies. Implications of the phenomena and ways of improving transport and potential applications spanning configurable microfluidics, antennas, tunable lenses, diagnostics, sensing, and active Kerr and other devices are discussed.

Geometrical features are known to be very important in neuronal growth and the formation of neuronal networks. We present an experimental and theoretical investigation of axonal growth and dynamics for neurons cultured on patterned polydimethylsiloxane surfaces. We utilize fluorescence microscopy to image the axonal dynamics and show that these substrates impart a strong directional bias to neuronal growth. We model axonal dynamics using a general stochastic model and use this framework to extract key dynamical parameters. These results provide novel insight into how geometrical cues influence neuronal growth and represent important advances toward bioengineering neuronal growth platforms.

Epitaxial Sm0.6Nd0.4NiO3 thin films were grown on different substrates by pulsed laser deposition. X-ray diffraction indicates that for SLAO substrate, strain relaxation is accompanied by the creation of oxygen vacancies. The film resistivity on LaAlO3 and SrTiO3 substrates shows a clear insulator–metal transition (IMT) at 185 and 325 K, respectively, while the film is exclusively semiconducting on SrLaAlO4. At low temperatures, the conductivity of films deposited on SrLaAlO4 and SrTiO3 is described by the Mott variable-range hopping mechanism. With increasing film thickness, progressive tensile strain relaxation takes place, which in turn results in a gradual decrease in the IMT temperature.

Nanoporous Au shows the antimicrobial activity without the release of ROS. The cell wall is hyperpolarized by npAu. Hence, the hyperpolarized cell wall may affect ATP synthase, leading to the bacterial death. In the present work, the effects of the hyperpolarized cell wall on the structure and functions of Asp61 in ATP synthase are investigated by molecular dynamics simulations and first-principles calculations. The simulations suggest that the Asp61 is more negatively hyperpolarized, which is due to the strengthened O–H bond in Asp61, in interacting with the hyperpolarized cell wall, which results in the disturbance of proton transport in ATP synthase.

Material changes in yttrium-doped barium zirconate, BaZr0.8Y0.2O3–x, were studied using in situ Raman spectroscopy and ex situ x-ray photoelectron spectroscopy analysis. During in situ Raman analysis, samples were heated to temperatures of 300–600 °C and exposed to both dry and humidified H2 atmospheres. At the lower temperatures (300–450 °C), a new vibrational peak appears in the Raman spectra during exposure to humidified H2. The appearance of this feature is reversible, dependent on previous sample history, and possibly results from new, secondary phase formation or lattice distortion.

To improve the stability of Cs2SnCl6 under aqueous/moisture environments, we applied a concept of artificial passivation by depositing a protective TiO2 coating of 10 nm on the surface of Cs2SnCl6. Static leaching experiments results indicate that the initial release rates of Cs+ and Cl− are decreased by 20–30 times with TiO2 coating, suggesting its possibility to improve the short-term water/environmental stability of Cs2SnCl6. An amorphous-to-crystalline phase transition in TiO2 film was observed, possibly resulting in degradation of Cs2SnCl6. However, the crystalline TiO2 film still remains after 21 days water exposure and can still act as an effective passivation layer to reduce the release rates of Cs+ and Cl- by as much as about 17 and 7 times, respectively, relative to static leaching without artificial coatings. Therefore, the water/environmental stability of metal halide perovskite Cs2SnCl6, which is a highly soluble molecular salt, can be enhanced by the nanoscale TiO2 coating as an artificial passivation film.

The extending market of concentrated solar power plants requires high-temperature materials for solar surface receivers that would ideally heat an air coolant beyond 1300 K. This work presents investigation on high-temperature alloys with ceramic coatings (AlN or SiC/AlN stacking) to combine the properties of the substrate (creep resistance, machinability) and coating (slow oxidation kinetics, high solar absorptivity). The first results showed that high-temperature oxidation resistance and optical properties of metallic alloys were improved by the different coatings. However, the fast thermal shocks led to high stress levels not compatible due to the differences in thermal expansion coefficients.

Waterproof bioelectrodes enable long-term biological monitoring and the assessment of performances of athletes in water. Existing gel electrodes change their electrical properties even when covered with a waterproof film. Here, the authors present the poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/poly(styrene-butadiene-styrene) (SBS) bi-layer nanosheet and waterproof film for a comfortable waterproof bioelectrode. PEDOT:PSS/SBS is fully foldable with a conductivity loss of only 5%. This foldable nanosheet electrode provides a reliable electrical connection between the skin and the wire. The waterproof film-covered bioelectrode enables continuous monitoring of electrocardiograms in water, showing a signal-to-noise ratio of 21.5 dB for the R wave and 17.5 dB for the T wave, comparable to atmospheric measurements, and sensing a change in heart rate from 79 to 131 bpm during bathing.

With the aim of understanding the excitation energy transfer mechanism in natural photosynthetic membranes, light-harvesting (LH)2 and LH1-reaction center, which are pigment-protein complexes separated from Rhodobacter sphaeroides, were aligned on a planar electrode surface in stripe patterns at 5 µm intervals. Observation of the absorption spectrum and fluorescence microphotographs revealed selective immobilization and conservation of the pigments. Photocurrent signals were obtained when the electrode was illuminated at either 880 or 800 nm. The fabricated structure was confirmed to function as a natural photosynthetic membrane with the highest photocurrent signal being obtained when using a co-immobilized substrate under excitation at 800 nm.

We demonstrate that fluorescence properties of organic fluors embedded in a porous polystyrene matrix are highly sensitive to the average pore size and pore-size distribution of the matrix. The effect can be understood as two different types of confinement imposed to the fluor molecules by the matrix. First, there is geometrical confinement that restricts the fluor oscillations due to its physical contact with a pore wall. Second, there is an electronic confinement due to a local polarization of the wall material by molecular dipoles. The effects lead to a spectral shift and enhancement of the fluorescence intensity of the material.

TiAlN, CrAlN films and alternate CrAlN/TiAlN multilayers with different repeated bilayer thickness ranging from 10 to 30 nm were prepared by reactive magnetron sputtering. The interface structures of the films were characterized using x-ray reflectometry method. The individual thickness of the repeated bilayers in multilayers and total thickness of the films are close to the nominal thickness and they are more accurate for thicker films. The interface roughness increases as the thickness of the repeated bilayer in mutilayers decreases. The scattering length density profiles of the films suggests that the chemical composition is more accurate for thicker films.