Investigating PEDOT:PSS Binder as an Energy Extender in Sulfur Cathodes for Li-S Batteries.

Although lithium-sulfur (Li-S) batteries offer a high theoretical energy density, shuttling of dissolved sulfur and polysulfides is a major factor limiting the specific capacity, energy density, and cyclability of Li-S batteries with a liquid electrolyte. Cathode host materials with a microstructure to restrict the migration of active material may not totally eliminate the shuttling effect or may create additional problems that limit the full dissolution and redox conversion of all active cathode materials. Selecting a cathode coating binder with a multifunctional role offers a universal solution suitable for various cathode hosts.

Advancements and challenges in strained group-IV-based optoelectronic materials stressed by ion beam treatment.

In this perspective article, we discuss the application of ion implantation to manipulate strain (by either neutralizing or inducing compressive or tensile states) in suspended thin films. Emphasizing the pressing need for a high-mobility silicon-compatible transistor or a direct bandgap group-IV semiconductor that is compatible with complementary metal-oxide-semiconductor technology, we underscore the distinctive features of different methods of ion beam-induced alteration of material morphology. The article examines the precautions needed during experimental procedures and data analysis and explores routes for potential scalable adoption by the semiconductor industry.

Benchmarking of X-Ray Fluorescence Microscopy with Ion Beam Implanted Samples Showing Detection Sensitivity of Hundreds of Atoms.

Single impurities in insulators are now often used for quantum sensors and single photon sources, while nanoscale semiconductor doping features are being constructed for electrical contacts in quantum technology devices, implying that new methods for sensitive, non-destructive imaging of single- or few-atom structures are needed. X-ray fluorescence (XRF) can provide nanoscale imaging with chemical specificity, and features comprising as few as 100 000 atoms have been detected without any need for specialized or destructive sample preparation. Presently, the ultimate limits of sensitivity of XRF are unknown - here, gallium dopants in silicon are investigated using a high brilliance, synchrotron source collimated to a small spot.

The role of surface stoichiometry in NO gas sensing using single and multiple nanobelts of tin oxide.

Typically used semiconducting metal oxides (SMOs) consist of several varying factors that affect gas sensor response, including film thickness, grain size, and notably the grain-grain junctions within the active device volume, which complicates the analysis and optimisation of sensor response. In comparison, devices containing a single nanostructured element do not present grain-grain junctions, and therefore present an excellent platform to comprehend the correlation between nanostructure surface stoichiometry and sensor response to the depletion layer (Debye length, LD) variation after the analyte gas adsorption/chemisorption. In this work, nanofabricated devices containing SnO2 and Sn3O4 individual nanobelts of different thicknesses were used to estimate their LD after NO2 exposure.

Complete Atomic Oxygen and UV Protection for Polymer and Composite Materials in a Low Earth Orbit.

With the realization of larger and more complex space installations, an increase in the surface area exposed to atomic oxygen (AO) and ultraviolet (UV) effects is expected, making structural integrity of space structures essential for future development. In a low Earth orbit (LEO), the effects of AO and UV degradation can have devastating consequences for polymer and composite structures in satellites and space installations. Composite materials such as carbon fiber-reinforced polymer (CFRP) or polymer materials such as polyetherimide and polystyrene are widely used in satellite construction for various applications including structural components, thermal insulation, and importantly radio frequency (RF) assemblies.

Electrical semiconduction modulated by light in a cobalt and naphthalene diimide metal-organic framework.

Metal-organic frameworks (MOFs) have emerged as an exciting class of porous materials that can be structurally designed by choosing particular components according to desired applications. Despite the wide interest in and many potential applications of MOFs, such as in gas storage, catalysis, sensing and drug delivery, electrical semiconductivity and its control is still rare. The use and fabrication of electronic devices with MOF-based components has not been widely explored, despite significant progress of these components made in recent years.

Prevalence of Lead Hazards and Soil Arsenic in U.S. Housing.

The American Healthy Homes Survey, June 2005-March 2006, measured levels of lead and arsenic in homes nationwide. Based on a three-stage cluster sample of 1,131 housing units, key statistically weighted estimates of the prevalence of lead-based paint (LBP) and LBP hazards associated with paint, dust, and soil, and arsenic in dust and soil, were as follows: 37.1 million homes (35%) had some LBP; 23.

3D mapping of intensity field about the focus of a micrometer-scale parabolic mirror.

We report on the fabrication and diffraction-limited characterization of parabolic focusing micromirrors. Sub-micron beam waists are measured for mirrors with 10-μm radius aperture and measured fixed focal lengths in the range from 24 μm to 36 μm. Optical characterization of the 3D intensity in the near-field produced when the device is illuminated with collimated light is performed using a modified confocal microscope.

Microscopic insight into the bilateral formation of carbon spirals from a symmetric iron core.

Mirrored carbon-spirals have been produced from pressured ferrocene via the bilateral extrusion of the spiral pairs from an iron core. A parametric plot of the surface geometry displays the fractal growth of the conical helix made with the logarithmic spiral. Electron microscopy studies show the core is a crystalline cementite which grows and transforms its shape from spherical to biconical as it extrudes two spiralling carbon arms.

Facile synthesis of titania nanowires via a hot filament method and conductometric measurement of their response to hydrogen sulfide gas.

Titania nanostructures are of increasing interest for a variety of applications, including photovoltaics, water splitting, and chemical sensing. Because of the photocatalytical properties of TiO₂, chemical processes that occur at its surface can be exploited for highly efficient nanodevices. A facile and fast synthesis route has been explored that is free of catalysts or templates.

Spontaneous emergence of long-range shape symmetry.

Self-organization of matter is essential for natural pattern formation, chemical synthesis, as well as modern material science. Here we show that isovolumetric reactions of a single organometallic precursor allow symmetry breaking events from iron nuclei to the creation of different symmetric carbon structures: microspheres, nanotubes, and mirrored spiraling microcones. A mathematical model, based on mass conservation and chemical composition, quantitatively explains the shape growth.

The route to single magnetic particle detection: a carbon nanotube decorated with a finite number of nanocubes.

We propose an experimental technique that allows us a straightforward and reliable fabrication of magnetic and electromechanical nanodevices for single particle detection and characterization. We demonstrate three different experimental methods for fabrication of nanoscale devices consisting of either single or multiwall carbon nanotubes bridging metallic electrodes and decorated with magnetic iron/iron oxide nanocubes with a size of 18 nm. Electrical characterization of the devices as well as structural and magnetic investigations of nanoparticles are reported.

American Healthy Homes Survey: a national study of residential pesticides measured from floor wipes.

The U.S. Department of Housing and Urban Development in collaboration with the United States Environmental Protection Agency conducted a survey measuring lead, allergens, and insecticides in a randomly selected nationally representative sample of residential homes.

On the importance of the electrostatic environment for the transport properties of freestanding multiwall carbon nanotubes.

Electrical measurements of freestanding multiwall carbon nanotubes using high resistance tunnelling contacts reveal a power law behaviour, I alpha V alpha + 1, with alpha as high as 5.2, followed by a transition to an offset ohmic behaviour. The freestanding electrode geometry allows for a distinction between the predictions from Luttinger liquid and environmental quantum fluctuation (EQF) theories to be made.

RF response of single-walled carbon nanotubes.

We present for the first time an in-depth study of the RF response of a single-walled carbon nanotube (SWCNT) rope. Our novel electrode design, based on a tapered coplanar approach, allows for single tube measurements well into the GHz regime, minimizing substrate-related parasitics. From the analysis of the S-parameters, the ac transport mechanism in the range 30 kHz to 6 GHz is established.