Observations of specimen morphology effects on near-zone-axis convergent-beam electron diffraction patterns.

This work presents observations of symmetry breakages in the intensity distributions of near-zone-axis convergent-beam electron diffraction (CBED) patterns that can only be explained by the symmetry of the specimen and not the symmetry of the unit cell describing the atomic structure of the material. The specimen is an aluminium-copper-tin alloy containing voids many tens of nanometres in size within continuous single crystals of the aluminium host matrix. Several CBED patterns where the incident beam enters and exits parallel void facets without the incident beam being perpendicular to these facets are examined.

Combination of Chemotherapy and Mild Hyperthermia Using Targeted Nanoparticles: A Potential Treatment Modality for Breast Cancer.

Despite the clinical benefits that chemotherapeutics has had on the treatment of breast cancer, drug resistance remains one of the main obstacles to curative cancer therapy. Nanomedicines allow therapeutics to be more targeted and effective, resulting in enhanced treatment success, reduced side effects, and the possibility of minimising drug resistance by the co-delivery of therapeutic agents. Porous silicon nanoparticles (pSiNPs) have been established as efficient vectors for drug delivery.

From nanoparticles to crystals: one-pot programmable biosynthesis of photothermal gold structures and their use for biomedical applications.

Inspired by nature, green chemistry uses various biomolecules, such as proteins, as reducing agents to synthesize metallic nanostructures. This methodology provides an alternative route to conventional harsh synthetic processes, which include polluting chemicals. Tuning the resulting nanostructure properties, such as their size and shape, is challenging as the exact mechanism involved in their formation is still not well understood.

Stoichiometry-grain size-specific capacitance interrelationships in nickel oxide.

Nickel oxide exhibits almost the highest theoretical specific capacitance ( ), which includes contributions from non-faradaic double layer charging and faradaic OH adsorption. However, the realistic and tangible is due to the faradaic process, which can be influenced by chemical ( stoichiometry) and structural ( grain size) changes. Hence, it is necessary to investigate the interrelationships among chemical and structural features and charge storage capacity.

Chemical Fingerprinting of Polymers Using Electron Energy-Loss Spectroscopy.

Electron energy-loss spectroscopy (EELS) is becoming an important tool in the characterization of polymeric materials. The sensitivity of EELS to changes in the chemical structure of polymeric materials dictates its applicability. In particular, it is important for compositional analysis to have reference spectra of pure components.

Transforming solid-state precipitates via excess vacancies.

Many phase transformations associated with solid-state precipitation look structurally simple, yet, inexplicably, take place with great difficulty. A classic case of difficult phase transformations is the nucleation of strengthening precipitates in high-strength lightweight aluminium alloys. Here, using a combination of atomic-scale imaging, simulations and classical nucleation theory calculations, we investigate the nucleation of the strengthening phase θ' onto a template structure in the aluminium-copper alloy system.

Mechanical, Electrical, and Crystallographic Property Dynamics of Bent and Strained Ge/Si Core-Shell Nanowires As Revealed by in situ Transmission Electron Microscopy.

Research on electromechanical properties of semiconducting nanowires, including plastic behavior of Si nanowires and superb carrier mobility of Ge and Ge/Si core-shell nanowires, has attracted increasing attention. However, to date, there have been no direct experimental studies on crystallography dynamics and its relation to electrical and mechanical properties of Ge/Si core-shell nanowires. In this Letter, we in parallel investigated the crystallography changes and electrical and mechanical behaviors of Ge/Si core-shell nanowires under their deformation in a transmission electron microscope (TEM).

Photocatalysis with Pt-Au-ZnO and Au-ZnO Hybrids: Effect of Charge Accumulation and Discharge Properties of Metal Nanoparticles.

Metal-semiconductor hybrid nanomaterials are becoming increasingly popular for photocatalytic degradation of organic pollutants. Herein, a seed-assisted photodeposition approach is put forward for the site-specific growth of Pt on Au-ZnO particles (Pt-Au-ZnO). A similar approach was also utilized to enlarge the Au nanoparticles at epitaxial Au-ZnO particles (Au@Au-ZnO).

Topologically Enclosed Aluminum Voids as Plasmonic Nanostructures.

Recent advances in the ability to synthesize metallic nanoparticles with tailored geometries have led to a revolution in the field of plasmonics. However, studies of the important complementary system, an inverted nanostructure, have so far been limited to two-dimensional sphere-segment voids or holes. Here we reveal the localized surface plasmon resonances (LSPRs) of nanovoids that are topologically enclosed in three-dimensions: an "anti-nanoparticle".

Nanostructured photoelectrochemical solar cell for nitrogen reduction using plasmon-enhanced black silicon.

Ammonia (NH3) is one of the most widely produced chemicals worldwide. It has application in the production of many important chemicals, particularly fertilizers. It is also, potentially, an important energy storage intermediate and clean energy carrier.

Direct mapping of Li-enabled octahedral tilt ordering and associated strain in nanostructured perovskites.

Self-assembled nanostructures with periodic phase separation hold great promise for creating two- and three-dimensional superlattices with extraordinary physical properties. Understanding the mechanism(s) driving the formation of such superlattices demands an understanding of their underlying atomic structure. However, the nanoscale structural fluctuations intrinsic to these superlattices pose a new challenge for structure determination methods.

Interpretation of angular symmetries in electron nanodiffraction patterns from thin amorphous specimens.

The interpretation of angular symmetries in electron nanodiffraction patterns from thin amorphous specimens is examined. It is found that in general there are odd symmetries in experimental electron nanodiffraction patterns. Using simulation, it is demonstrated that this effect can be attributed to dynamical scattering, rather than other divergences from the ideal experimental conditions such as probe-forming lens aberrations and camera noise.

A multi-responsive intrinsically disordered protein (IDP)-directed green synthesis of fluorescent gold nanoclusters.

Herein we demonstrate the green synthesis of fluorescent gold nanoclusters (AuNCs) using a multi-responsive intrinsically disordered protein (IDP) polymer, Rec1-resilin, as a multi-functional template. In a controlled environment, Rec1-resilin acts simultaneously as the directing agent and the reducer, and performs the role of a highly efficient stabilizer once AuNCs are formed. The evolution of the photophysical properties and the chemical states of AuNCs formed are measured using UV-Vis, fluorescence and X-ray photoelectron spectroscopy.

Plasmonic Ge-doped ZnO nanocrystals.

We present the first colloidal synthesis of Ge-doped ZnO nanocrystals, which are produced by a scalable method that uses only air and moisture stable precursors. The incorporation of tetravalent Ge ions within ZnO nanocrystals generates a surface plasmon resonance in the near-mid infrared, and induces a change in morphology, from isotropic spheroidal nanocrystals to rod-like, elongated structures with a distinctive c-axis orientation.

Nanofabrication of highly ordered, tunable metallic mesostructures via quasi-hard-templating of lyotropic liquid crystals.

The synthesis of metal frameworks perforated with nanotunnels is a challenge because metals have high surface energies that favor low surface area structures; traditional liquid-crystal templating techniques cannot achieve the synthetic control required. We report a synthetic strategy to fabricate metal nanomaterials with highly ordered, tunable mesostructures in confined systems based on a new quasi-hard-templating liquid-crystals mechanism. The resulting platinum nanowires exhibit long range two-dimensional hexagonally ordered mesopore structures.

Ending aging in super glassy polymer membranes.

Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position.

Efficient atomic-scale kinetics through a complex heterophase interface.

Atomic-scale imaging and first-principles modeling are applied to the heterophase interface between the Al-Cu solid solution (αCu) and θ' (Al2Cu) phases. Contrary to recent studies, our observations reveal a diffuse interface of complex but well-defined structure that enables the progression from αCu to θ' over a distance of ≈1  nm. We demonstrate that, surprisingly, the observed interfacial structure is not preferred on energetic grounds.

Compositional uniformity, domain patterning and the mechanism underlying nano-chessboard arrays.

We propose that systems exhibiting compositional patterning at the nanoscale, so far assumed to be due to some kind of ordered phase segregation, can be understood instead in terms of coherent, single phase ordering of minority motifs, caused by some constrained drive for uniformity. The essential features of this type of arrangement can be reproduced using a superspace construction typical of uniformity-driven orderings, which only requires the knowledge of the modulation vectors observed in the diffraction patterns. The idea is discussed in terms of a simple two-dimensional lattice-gas model that simulates a binary system in which the dilution of the minority component is favoured.

Gold nanothorns-macroporous silicon hybrid structure: a simple and ultrasensitive platform for SERS.

We synthesised a novel gold-on-porous silicon hybrid material that exhibits a highly sensitive and reproducible surface-enhanced Raman spectroscopy (SERS) response. The material was fabricated simply by reducing gold chloride with hydrofluoric acid on the surface of macro-porous silicon (macro-PSi). The material consists of thorn-shaped gold nanocrystals with characteristic shapes and sizes on the surface of macro-PSi.

A simple route to full structural analysis of biophosphates and their application to materials discovery.

An integrated suite of synthesis and characterisation techniques that includes synchrotron-based single crystal, powder X-ray diffraction, nuclear magnetic resonance and electron diffraction have been employed to uncover two new distinct structures in the Ca(x)Ba(2-x)P(2)O(7) polymorphic phosphate system. These materials have particular relevance for their application as both biomaterials and phosphors. Calcium barium pyrophosphate, CaBaP(2)O(7), was shown by a combination of spectroscopic and diffraction techniques to have two polymorphs distinct in structure from all of the five previously reported polymorphs of Ca, Sr and Ba pyrophosphate.

Atom-scale ptychographic electron diffractive imaging of boron nitride cones.

Ptychographic coherent diffractive imaging (CDI) has been extensively applied using both x rays and electrons. The extension to atomic resolution has been elusive. This Letter demonstrates ptychographic electron diffractive imaging at atomic resolution, permitting identification of structure in a boron nitride helical cone at a resolution of order 1 Å, beyond that of comparative Z-contrast images.

Periodic mesoporous Li(x)(Mn(1/3)Ni(1/3)Co(1/3))O2 spinel.

A monoclinic periodic mesoporous Li(x)(Mn(1/3)Ni(1/3)Co(1/3))O(2) spinel has been successfully prepared for the first time using a 'two solvents' pore infiltration methodology on hard silica templates. More commonly used synthetic techniques are not applicable to this complex material. This important battery cathode has a surface area of over 180 m(2)g(-1) and a pore size of 5.

Direct electrodeposition of porous gold nanowire arrays for biosensing applications.

Nanochannel alumina templates are used as templates for fabrication of porous gold nanowire arrays by a direct electrodeposition method. After modification with glucose oxidase, a porous gold nanowire-array electrode is shown to be an excellent electrochemical biosensor for the detection of glucose. The picture shows an SEM image of a nanowire array after removal of the alumina template by acid dissolution.