A novel process for Boron doping of ultrananocrystalline diamond (UNCD) films, using thermal diffusion, is described. Hall measurements show an increase in carrier concentration from 1013 to 1020 cm−3. Ultraviolet Photoelectron Spectroscopy and x-ray Photoelectron Spectroscopy show a band gap of 4.4 eV, a work function of 5.1 eV and a Fermi level at 2.0 eV above the valence band. Boron atoms distribution through UNCD films, was measured by Secondary Ion Mass Spectrometry, revealing Boron atoms diffusivity of about 10−14 cm2/s. Raman spectroscopy and x-ray Diffraction analysis revealed that UNCD films did not suffer graphitization nor structural damage during annealing.

The present work focuses on the radiation-modification of chitosan (CS) with N,N-dimethylacrylamide (DMAAm) presented as three different architectures: comb-type grafting hydrogels (net-CS)-g-DMAAm, interpenetrating networks of CS and DMAAm (net-CS)-inter-(net-DMAAm), and semi-interpenetrating networks (net-DMAAm)-inter-CS. The syntheses of different polymeric architectures were realized by gamma irradiation by a 60Co source. The optimum conditions for the syntheses of the three systems were at a dose of 6 kGy. Only the comb-type system presented a well-defined critical pH. All the hydrogels showed porous and interconnected structures according to scanning electronic microscopy. These different architectures could be used as three-dimensional cell culture scaffolding.

Supercapacitor has received intense interest due to its high-charge/discharge rate and high-power density. C/Fe2O3 layer with different C/Fe ratios were synthesized by a solution-based approach for supercapacitor application. The influence of synthesis conditions on their electrochemical performances was investigated. Cobalt was added into C/Fe2O3 and significant improved its performance. The optimal C/Fe2O3 sample gives a high specific capacitance of 85.3 F/g and the addition of Co3O4 further increase the capacitance of obtained C/Fe2O3/Co3O4 to 144.4 F/g at 5 A/g. This work demonstrates an efficient supercapacitor application of low-cost metal oxides and facile solution-based synthesis approach.

In this study, a comparison of the tensile behavior of fully nanotwinned Cu–6 wt.%Al, Cu–2 wt.%Al, and Cu–10 wt.%Ni with stacking fault energies (SFEs) of 6, 37, and 60 mJ/m2, respectively is presented. The samples displayed yield strengths ranging from 830 to 1340 MPa, varying with both alloy content and microstructural parameters. All samples showed low ductility, even though there are tilted twin boundaries present in Cu–10 wt.%Ni. The influence of varying grain width is presented for each alloy and related to both the activation volume and SFE [Figs. 3(a)–3(c)].

The authors demonstrate that gold-binding peptides displayed on the outer membrane of Escherichia coli enhance bioelectrochemical charge transfer by binding gold nanoparticles. Microbial fuel cells were run with different gold-binding peptides displayed and with different nanoparticle sizes, and the results were correlated with transmission electron microscopy (TEM) imaging of nanoparticle binding. When a gold-binding peptide is displayed and 5 nm gold nanoparticles are present, up to 4× power generation over E. coli not displaying a gold-binding peptide is observed. While an enhanced current is observed using the previously published M6G9, the largest enhancement is observed when a new longer peptide named M9G18 is used.

In this work, we present a solvothermal method to prepare bismuth (Bi)-doped CuGaS2 chalcopyrite nanocrystals ink and apply it to an all-solution-processed approach for the preparation of films with a thickness of approximately 730 nm and with enhanced optical properties and lower band gap energy than the undoped semiconductor films. The low-cost deposition method is comprised by spray deposition of the chalcogenide nanocrystals ink onto the molybdenum substrates, producing microcrystalline films with grains larger than 400 nm originated from coalescence of Bi-doped nanocrystals. Bi-doped CuGaS2 microcrystalline films are a good candidate to be applied as an absorber layer in thin-film solar cells.

A piezoelectric biomedical microelectromechanical system (bioMEMS) cantilever device was designed and fabricated to act as either a sensing element for muscle tissue contraction or as an actuator to apply mechanical force to cells. The sensing ability of the piezoelectric cantilevers was shown by monitoring the electrical signal generated from the piezoelectric aluminum nitride in response to the contraction of iPSC-derived cardiomyocytes cultured on the piezoelectric cantilevers. Actuation was demonstrated by applying electrical pulses to the piezoelectric cantilever and observing bending via an optical detection method. This piezoelectric cantilever device was designed to be incorporated into body-on-a-chip systems.

We analyze charge density transfer from water to solvated transition metal (TM) ions in different formal oxidation states (FOSs) in aqueous solution by first principles and relate the degree of stabilization of the solvated cations to the charge donation from the water ligands. We find remarkable charge stability on the metal center regardless of FOSs. This effect is similar to what has previously been shown for charges on TM cations in inorganic crystals. This ligand-to-metal charge transfer results in softening of the ligand O–H bonds, which can be used to explain the formation of higher-FOS transition metalates and oxycations.

The practical realization of rechargeable organic batteries is stalled by their low electron conductivity, which limits the organic-active material content in the electrode composite and results in a low net electrode energy density. Additionally, the dissolution of active materials into the electrolyte causes a short cycle life. In this study, a conductive polymer mixture, poly(3,4-ethylenedioxythiophene)/polystyrenesulfonate, containing a small amount of sugar alcohol was used as the binder and separator in a rechargeable organic battery. Consequently, the active material content was increased up to 80 wt%, and the cycle life was extended.

CdS/ZnS core shell quantum dots (QDs) were synthesized and functionalized by methionine and characterized by standard techniques. The prior QD-based phytotoxicity assay was helpful to find out the maximum tolerant level of the plant cells. The successful transport and phytotoxic mechanism of QDs were elaborated in detail. Methionine functionalities on the QDs were helpful in specific binding of QDs with the nucleus of stomata in plant cells. Target specific interaction with the nucleus of stomata cells was a novel breakthrough that can be used in many biologic applications.

The electrochemical catalytic effects of the NiO islands and layer on n-type GaN were investigated. The NiO islands covered some parts of the GaN surface and were seen to improve photoanodic current and prevent photoanodic corrosion. However, the NiO layer was found to worsen the photoanodic current. Hole transportation is thought to occur from the GaN valence band edge to the NiO valence band edge in their surface plane direction due to the band alignment. In addition, the electron capture for water oxidation is expected to be the valence band edge of the NiO instead of the intermediate state.

The thermal history of amorphous polymers near the glass-transition temperature determines the extent to which macromolecules structurally relax, and ultimately their properties. Here, we report the correlation between physical aging, dielectric breakdown, and capacitive energy storage of polystyrene, poly(methyl-methacrylate), and associated silica nanocomposites. Guided by enthalphic recovery rates, dielectric breakdown strength increased from 20% to 40% when aged at Tg−10 °C before use. The generality of improvement and connection to enthalpic recovery afford a means to design pre-service processing of new polymers and additive manufacturing techniques to reduce excess volume within the glass; and thereby reduce initiation and inhibit propagation of electronic failure.

In this work, the authors report a facile method for the preparation of brush-structured nanocomposites of sulfur–polyaniline–graphene oxide (S–PANI–G) that were used for cathode materials of lithium–sulfur batteries (LSBs). The morphology and structure of composite were studied by x-ray photoelectron microscopy, transmission electron microscopy, scanning electron microscopy, and x-ray diffraction analysis. The nanocomposites exhibited good electrochemical performance involving good rate performance, high capacity, and promising cycling stability. The good performance of S–PANI–G results from the synergistic effect of sulfur, polyaniline, and graphene oxide. The composite and method reported here pave the way for the design and synthesis of novel cathode materials for LSBs.

We investigate the impact of increasing number density of self-catalyzed GaAs nanowires (NWs) on their crystal structure, grown by molecular beam epitaxy. To this end, we employ an iterative, lithography-free approach for varying the number density of self-catalyzed GaAs NWs grown on Si(111) covered with native oxide. We use scanning electron microscopy and x-ray diffraction in combination with simulations based on the extended Markov model for the morphologic characterization of the so obtained NWs. Our findings show how both the shape of the Ga-droplet and the NW crystal structure are affected even by relatively small changes of the wire number density, allowing for a quantification of its influence on the local NW growth conditions at nominally identical growth parameters.

Inflammation is facilitated largely by macrophages and other white blood cells, which recognize and respond to evolutionarily conserved damage-associated molecular patterns that are released upon tissue injury and cell stress. Damage-associated molecular patterns are known to bind Toll-like receptors (TLRs) and initiate inflammatory responses through MyD88-dependent NF-κB signaling. Biomaterial implantation activates the innate immune system, resulting in a chronic inflammatory response known as a foreign body reaction (FBR). In this review, the authors discuss the current understanding of damage-initiated TLR signaling in the FBR and the significance of this response in the success of implanted devices.

The main challenges of developing advanced surface-enhanced Raman spectroscopy (SERS) sensors lie in the poor reproducibility, low uniformity, and the lack of molecular selectivity. In this paper, we report a facile and cost-effective approach for the large-scale patterning of graphene-encapsulated Au nanoparticles on Si substrate as efficient SERS sensors with highly-improved uniformity, reproducibility, and unique selectivity. The materials production was accomplished via an industry-applicable galvanic deposition—annealing—chemical vapor deposition approach, followed by a final plasma treatment. Our study provides a facile approach to the fabrication of uniform SERS substrate and further prompts the practical progress of SERS-based chemical sensors.

The Magnetoelectric (ME) effect has been observed in single phase hexaferrite bulk and thin films of SrCo2Ti2Fe8O19. In this paper we demonstrate that the ME linear coupling depends strongly on the Co ion concentration relative to the Ti ion concentration exhibiting extremum points at a concentration consistent with above formula. The Alternating Target Laser Ablation Deposition technique was utilized to deposit ME hexaferrite films for the first time. This allows for the deposition of transition metal ions at specific sites in the basic unit cell of the hexaferrite.

Nanoscale magnetization modulation by electric field enables the construction of low-power spintronic devices for information storage applications and, etc. Electric field-induced ion migration can introduce desired changes in the material's stoichiometry, defect profile, and lattice structure, which in turn provides a versatile and convenient means to modify the materials’ chemical-physical properties at the nanoscale and in situ. In this review, we provide a brief overview on the recent study on nanoscale magnetization modulation driven by electric field-induced migration of ionic species either within the switching material or from external sources. The formation of magnetic conductive filaments that exhibit magnetoresistance behaviors in resistive switching memory via foreign metal ion migration and redox activities is also discussed. Combining the magnetoresistance and quantized conductance switching of the magnetic nanopoint contact structure may provide a future high-performance device for non-von Neumann computing architectures.

Catalyst development is needed to enable the use of renewable electricity to chemically convert carbon dioxide (CO2) and water into fuels and chemicals, a more sustainable, lower-carbon alternative to conventional processes that produce fuels and chemicals based on fossil resources. In this study, the catalytic activity and selectivity of polycrystalline platinum (Pt) is thoroughly characterized for the CO2 reduction reaction, based on an electrochemical cell design that offers high sensitivity for product detection. Thin polyaniline films are then electrodeposited onto polycrystalline Pt foils to form hybrid organic–inorganic surfaces. The addition of the polymer is observed to have an impact on the catalytic chemistry, yielding up to a fivefold enhancement in formate and CO production over pure Pt foils. This work elucidates new strategies to perturb interfacial chemistry in a manner that could help steer CO2 electro-reduction catalysis in desired directions.

Low-voltage-driven organic thin-film transistors (organic TFTs) with spatially controlled threshold voltages (−1.2 and −0.36 V) were fabricated for the first time. Using the microcontact printing method, tetradecylphosphonic acid (HC14-PA) and pentadecylfluoro-octadecylphosphonic acid (FC18-PA) were transferred to form ultrathin layers in different regions on a substrate. Together with plasma-grown aluminum oxide (AlOx) layer, the stamped layers were shown to have equal insulating ability as the dipped method monolayer. The feasibility of the area-selective stamping method was displayed using locally controlled inverter circuits. The shift of turn-on voltage for those transistors was consistent with the threshold voltage shift of the transistors.