The point spread function (PSF) of the scanning electron microscope (SEM) can be determined using a recently developed nanoparticle calibration method. Many parameters are involved in PSF determination and introduce a previously unstudied amount of uncertainty into the PSF size and shape. Signal type, support material thickness, reference particle size, PSF smoothing (K), and background correction were investigated regarding their effect on the PSF. Experimental data were complemented by CASINO simulations. Differences in detector position between the observed particles and the method's simulated reference particles caused shifting between secondary electron PSFs and backscattered electron PSFs. Support material thickness did not have a practical effect on the PSF at the tested voltages. Uncertainty in reference particle size varied the PSF full width at half maximum (FWHM) within ±0.7 nm at 2σ, with virtually no uncertainty in some cases. K and background correction within a reasonable range of values resulted in PSF FWHM differences within ±0.9 nm, except at 2 kV for K with an upper bound of ±1.9 nm due to increased noise. Tailoring K and background correction case-by-case would result in smaller differences. The interconnection of these parameters may help in future efforts to calculate their best selection.

This paper is devoted to the study of formation mechanism of metal solid solutions during the thermolysis of single-source precursors in Co–Pt systems with a wide range of superstructural ordering. It is shown that the thermal decomposition of [Pt(NH3)4][Co(C2O4)2(H2O)2]·2H2O salt in helium is critically different from that under hydrogen atmospheres. Thermal degradation under the helium atmosphere is followed by a gradual reduction of platinum and cobalt, and at each thermolysis temperature only one phase is present. At 380 °C an equiatomic Co0.50Pt0.50 solid solution is formed (a = 3.749 (4) Å, Fm−3m space group, V/Z = 13.17 Å3, crystallite size: 5–7 nm). When the precursor is decomposed under a hydrogen atmosphere, the process proceeds mainly through the simultaneous reduction of the platinum and cobalt atoms, and at each temperature section two metal phases are present. The formation of the close to equiatomic Co0.50Pt0.50 solid solution (a = 3.782 (4) Å, Fm−3m space group, V/Z = 13.52 Å3, crystallite size: 7–9 nm) occurs at 450 °C. The calculations of crystallite sizes are confirmed by transmission electron microscopy data.

The shape- and structure-directing ability of capping agents, namely, acetic acid (AA) and folic acid (FA), has been analyzed in the synthesis of hollow plasmonic nanostructures via the nanoscale Kirkendall effect. FA was found to possess both shape-directing and structure-directing abilities when spherical solid Ag2O nanoparticles were transformed into hollow silver nanocubes (HAgNCs). In contrast, AA acted only as a structure-directing agent in the transformation from solid Ag2O nanospheres to hollow Ag nanospheres (HAgNSs). FA capping leads to enhanced plasmon tunability range from 535 to 640 nm in the hollow silver nanostructures. The size and shape of nanostructures were analyzed by high-resolution transmission electron microscopy (HRTEM). HRTEM revealed that the outer diameter of AA-capped HAgNSs is 50 ± 10 nm while edge-length for FA-capped HAgNCs is 100 ± 15 nm. The diameter of inner void space was found to be 30 ± 5 and 43 ± 5 nm for HAgNSs and HAgNCs, respectively. The phase purity of the hollow nanostructures was confirmed by X-ray diffraction and energy dispersive X-ray measurements. Due to unique structural and plasmonic features, FA-capped HAgNCs are well-suited for biomedical applications.

The recent observation of spectacular photocatalytic activity enhancements generated tremendous interest in the synthesis, properties, and potential applications of black titania. Most black titania are core–shell structures consisting of a perfect crystalline core surrounded by a defective surface shell. Because the properties are attributed to the defective shell, it is particularly important, but very challenging, to obtain atomic structure information of the core, the shell, and the core–shell relationship on a single particle level. While the role of various synthesis approaches for producing black titania with different properties has been extensively reviewed, this review focuses on understanding the structure–functionality relationship in black titania on a single particle level. We start by introducing the crystal and electronic band structure of different TiO2 phases, followed by the discussion of particle size effects, the origin of lattice distortions, and phase control by synthesis, and concluding with the discussion of crystalline order formation and evolution creating the defective shell.

We report the first synthesis of highly homogenous Ce-doped YAG/ZnO core/shell nanoparticles (YAG:Ce/ZnO CSN) based on the hydrolysis/condensation of Zn(OAc)2 on the surface of YAG:Ce nanoparticles (NPs). Results show that YAG:Ce NPs of about 100 nm diameter are homogenously surrounded by a multilayer of highly crystallized ZnO nanocrystals (ZnO NCs) of 10–15 nm diameter with a core/shell structure. The as-prepared nanostructures have been used in the photocatalytic degradation of sulfathiazole (STZ), which is a molecule widely used as antibiotic, under UV-vis and visible light. The effect of YAG:Ce/ZnO weight ratio and YAG:Ce particle size on the photocatalytic efficiency of YAG:Ce/ZnO core/shell structures has been studied. The YAG:Ce/ZnO weight ratio of 1/1 was found to yield the optimal photocatalytic activity. Results also showed that YAG:Ce/ZnO CSN with 100 nm core size exhibited much higher photocatalytic activity compared to YAG:Ce/ZnO CSN with micro-sized YAG;Ce core. The recyclability of YAG:Ce/ZnO CSN photocatalyst was also demonstrated over at least 10 photocatalytic degradation cycles.

We propose a new method for preparing atom probe tomography specimens from nanoparticles using a fusible bismuth–indium–tin alloy as an embedding medium. Iron nanoparticles synthesized by the sodium borohydride reduction method were chosen as a model system. The as-synthesized iron nanoparticles were embedded within the fusible alloy using focused ion beam milling and ion-milled to needle-shaped atom probe specimens under cryogenic conditions. An atom probe analysis revealed boron atoms in a detected iron nanoparticle, indicating that boron from the sodium borohydride reductant was incorporated into the nanoparticle during its synthesis.

For thixoforming, it is necessary to have a good microstructure of fine, uniform, and globular grains in a semisolid range. In this study, the nano-Al2O3(Al2O3np)/Al7075 composites with a high solid fraction were fabricated by specially made Al2O3np containing Mg powders and semisolid ultrasonic vibration (SSUV) process. The influence of SSUV technology on primary α-Al grain and second phase in the composites was investigated. Microstructural studies revealed that a good semisolid slurry with an average grain size of 73 μm, a shape factor of 0.84, and a solid fraction of 0.715 could be obtained. Also, it could be shown that SSUV affected largely the size and type of the second phase as well as growth and nucleation of the primary α-Al grain. TEM analysis revealed that there are well-defined crystallographic orientation relationships between the second phases and α-Al, suggesting enhanced heterogeneous nucleation in Al7075 alloys. Moreover, mechanisms involved in the development of microstructure were discussed.

The influence of the concentration of carbon black nanoparticles on the mechanical behavior of a structural adhesive was studied to evaluate and understand the stiffness, strength, and deformation behavior of a reinforced epoxy adhesive. Two carbon black nanoparticles with different dielectric properties and sizes (Monarch® 120 and Vulcan® XC72R) were studied. A bi-component structural epoxy adhesive was selected. Specimens with different concentrations of carbon black were manufactured (0, 5, 10, and 20% on volume of resin) for each type of nanoparticle. The specimens were cured in a hydraulic hot-plates press machine. The mechanical behavior of the adhesives was found not to vary significantly as a function of carbon black nanoparticles amount. A scanning electron microscopy analysis was performed to evaluate the fracture surface. The fracture surfaces of specimens were correlated with the mechanical response obtained through tensile tests.

Birds have evolved in direct contact with natural nanoparticles (NPs) that are identical to artificial trace-element NPs. This relationship, the high action potential and their ability to reduce environmental pollution make NPs a promising component of bird diets. However, from available published studies there is no unity in justifying the applied dosages of NPs and their calculations. NPs are used in the studies in various doses, for example: Cu 0.5-50 mg/kg, Ag 10-1000 mg/kg, Se 0.2-5 mg/kg, Cr 500-1500 ppb. Therefore, universal approaches and criteria of NP investigations are necessary for the establishment of their use in feed.

The mechanisms of action of the trace elements in artificial NPs in birds vary from the those of ionic forms of trace elements, which determine the differences in the productive effect. According to data from different authors, chickens receiving NPs in feed have higher chickens body weight by 13-24%. Such benefits have increased interest in sources of trace-element NPs significantly over the past two decades. The design of trace-element NPs has led to promising developments in the safe use of NPs for poultry nutrition, such as coating NPs with inert substances and adjusting their size. However, constraining circumstances determined by the difficulty of predicting the toxic properties of nanostructures exist, even though artificial trace-element NPs are a relatively safe class of nanostructures due to their production requirements, and metal NPs are already used in human food and medicine. The following review discusses the benefits and potential hazardous effects of NPs and the possibility of using them as feed supplements for poultry.

Chagas disease is a public health problem, affecting about 7 million people worldwide. Benznidazole (BZN) is the main treatment option, but it has limited effectiveness and can cause severe adverse effects. Drug delivery through nanoparticles has attracted the interest of the scientific community aiming to improve therapeutic options. The aim of this study was to evaluate the cytotoxicity of benznidazole-loaded calcium carbonate nanoparticles (BZN@CaCO3) on Trypanosoma cruzi strain Y. It was observed that BZN@CaCO3 was able to reduce the viability of epimastigote, trypomastigote and amastigote forms of T. cruzi with greater potency when compared with BZN. The amount of BZN necessary to obtain the same effect was up to 25 times smaller when loaded with CaCO3 nanoparticles. Also, it was observed that BZN@CaCO3 enhanced the selectivity index. Furthermore, the cell-death mechanism induced by both BZN and BZN@CaCO3 was evaluated, indicating that both substances caused necrosis and changed mitochondrial membrane potential.

Electron tomography has become a valuable and widely used tool for studying the three-dimensional nanostructure of materials and biological specimens. However, the incomplete tilt range provided by conventional sample holders limits the fidelity and quantitative interpretability of tomographic images by leaving a “missing wedge” of unknown information in Fourier space. Imaging over a complete range of angles eliminates missing wedge artifacts and dramatically improves tomogram quality. Full-range tomography is usually accomplished using needle-shaped samples milled from bulk material with focused ion beams, but versatile specimen preparation methods for nanoparticles and other fine powders are lacking. In this work, we present a new preparation technique in which powder specimens are supported on carbon nanofibers that extend beyond the end of a tungsten needle. Using this approach, we produced tomograms of platinum fuel cell catalysts and gold-decorated strontium titanate photocatalyst specimens. Without the missing wedge, these tomograms are free from elongation artifacts, supporting straightforward automatic segmentation and quantitative analysis of key materials properties such as void size and connectivity, and surface area and curvature. This approach may be generalized to other samples that can be dispersed in liquids, such as biological structures, creating new opportunities for high-quality electron tomography across disciplines.

In this present study, different volume percentages of titanium dioxide nanoparticles were added as dispersions in commercially pure magnesium using the blend-press-sinter powder metallurgy process followed by hot extrusion. The physically blended titanium dioxide nanoparticles dispersoid induced a significant grain refinement in the extruded magnesium matrix. Characterization of the mechanical properties revealed that the increasing volume percentage of titanium oxide nanoparticles dispersion was effective in enhancing the ductility of magnesium without disturbing the strength under tensile loading and enhancing the strength of magnesium without disturbing the ductility under compressive loading. The dominating deformation mechanism in pure magnesium was the dislocation slip, which was subdued by the tensile twinning deformation mechanism due to the increasing presence of titanium dioxide dispersion. The effect of shift in the dominating deformation mechanism was displayed by the elimination of tensile-compressive asymmetry in magnesium when dispersed with 1 vol% of titanium dioxide nanoparticles.

In pursuit of design and characterisation of Cu adsorbing in thin films, we present data from a large variety of Cu-K edge X-ray Absorption Near Edge Spectroscopy (XANES) spectra obtained from organic and inorganic standards. Additionally, we have explored the impact of beam damage inducing redox alterations. Polymer nanoparticles were tested against films to produce higher concentration samples while maintaining high surface area to bulk effects. Spectra from nanoparticles were highly comparable to thin films of ~8 nm thickness, implying comparable contributions by surface effects on copper association. Finally, we observed no impact on Cu XANES spectra from vitrification with dimethyl sulfoxide to produce amorphous frozen, hydrated samples. The spectra should act as a valuable resource in assisting the design of experiments and identification of copper associations.

Ichthyophthirius multifiliis is a widespread, ciliated protozoan ectoparasite of fish. In the present study, we investigated the effects of metal nanoparticles on the reproduction and infectivity of free-living stages of I. multifiliis. We determined that ~50% of theronts could be killed within 30 min of exposure to either 20 ng mL−1 gold, 10 ng mL−1 silver or 5 ng mL−1 zinc oxide nanoparticles. Silver and zinc oxide nanoparticles at concentration of 10 and 5 ng mL−1 killed 100 and 97% of theronts, respectively and inhibited reproduction of tomonts after 2 h exposure. Gold nanoparticles at 20 ng mL killed 80 and 78% of tomonts and theronts 2 h post exposure, respectively. In vivo exposure studies using rainbow trout (Oncoryhnchus mykiss) demonstrated that theronts, which survived zinc oxide nanoparticles exposure, showed reduced infectivity compared with control theronts. No mortalities were recorded in the fish groups cohabited with theronts exposed to either nanoparticles compared with 100% mortality in the control group. On the basis of the results obtained from this study, metal nanoparticles particularly silver nanoparticles hold the best promise for the development of effective antiprotozoal agents useful in the management of ichthyophthiriosis in aquaculture.

X-ray diffraction (XRD) pattern of nanosized equimolar solid solution CoIr prepared by thermolysis of [Co(NH3)6][Ir(C2O4)3] contains peaks characteristic of both face-centered cubic (fcc) and hexagonal close-packed (hcp) structure. Moreover, 101 peak of hcp modification is substantially wider than 100 and 002 peaks, 102 and 103 are very broad and almost invisible. Peak 200 of fcc structure is wider than the other peaks of this modification and slightly shifted toward lower angles. It was shown by simulation of XRD patterns that particles of CoIr alloy are nanoheterogeneous and consist of lamellar domains having fcc and hcp structures. The best fit was obtained for the following model parameters: an average crystallites size is about 10 nm, average thicknesses of the fcc and hcp domains are 1.7 and 1.1 respectively. The presence of domain structure was confirmed by transmission electron microscopy data.

This study investigates the morphology changes in thin diblock copolymer (DiBCP) films occurring in the interaction with modified nanoparticles (NPs). Magnetite (Fe3O4) and silica (SiO x ) were prepared and used. Poly(pentyl methacrylate-b-methyl methacrylate) (PPMA-b-PMMA) (70/30 mol mol−1, hcp cylinders of the PMMA phase) DiBCP were employed to prepare thin films having thicknesses to realize standing cylinders in pure DiBCP films. The investigations aimed at two topics: (1) morphology after controlled incorporation of organo-modified NP (gold, silver, Fe3O4, SiO x ) and (2) additional solvent vapour annealing (SVA) with tetrahydrofuran (and chloroform for comparison). The laterally ordered morphology in thin films was examined by GISAXS and atomic force microscopy. Keeping the same type of morphology in nanocomposites, the dimensions of the periodic nanostructure altered depending on type and amount of incorporated NP. It was found that SiO x clusters enlarge the lateral distance of the PMMA cylinders, whereas metallic NPs reduce this parameter. Applying SVA improves the phase separation slightly, whereas lateral distances were kept constant or were reduced a little. Switching of domain orientation upon SVA could not be detected in the presence of NPs located at the polymer/substrate interface.

Aluminum (Al) nanoparticles are synthesized by wire explosion process (WEP) in an inert ambience of argon. Thermodynamic analysis and structural characterization of nano Al particles are made in the present work. Transmission electron microscopy (TEM) characterization has shown that the Al nanoparticles produced are spherical in shape and it follows a lognormal distribution. A unimodal size dependent thermodynamic model is formulated to understand the size dependent thermal behavior of aluminum nanoparticles. Three different melting modes such as, homogeneous melting mode (HMM), liquid skin melting (LSM) and liquid nucleation and growth (LNG) are assumed to understand the melting behavior of aluminum nanoparticles synthesized by the WEP process. The effect of saturation ratio on the nucleation rate and the impingement factor is also discussed. The size dependent melting and enthalpy of fusion of Al nanoparticles predicted by thermodynamic model are in tandem with the DSC results.

The potential of electrospray deposition, for the controlled preparation of particles for imaging in electron microscopes, is evaluated on various materials: from mono-modal suspensions of spherical particles to multimodal suspensions and to real-world industrial materials. It is shown that agglomeration is reduced substantially on the sample carrier, compared with conventional sample preparation techniques. For the first time, it is possible to assess the number concentration of a tri-modal polystyrene suspension by electron microscopy, due to the high deposition efficiency of the electrospray. We discovered that some suspension stabilizing surfactants form artifact particles during electrospraying. These can be avoided by optimizing the sprayed suspension.

In the present work, we report the development of phase pure and highly crystalline stibnite Sb2S3 nanostructures by a surfactant-mediated hydrothermal method. Polyvinylpyrrolidone (PVP) as the surfactant has a striking effect on the assembly of nanorods into dumbbell shaped nanorod-bundles. While nanorods with high aspect ratio were formed in absence of the surfactant, dumbbell shaped nanorod bundles were obtained using the surfactant. The structural, morphological, and optical properties were examined by X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy (XPS), and UV–visible spectrophotometer. Both XRD and Raman spectroscopy confirmed the formation of orthorhombic phase pure stibnite (Sb2S3). The ratio of Sb to S is found to be close to 2:3, corresponding to Sb2S3. The optical band gap varied in the range of 1.65–1.68 eV depending on the concentration of the surfactant.

The effect of heavy metal in fish has been the focus of extensive research for many years. However, the combined effect of heavy metals and nanomaterials is still a new subject that needs to be studied. The aim of this study was to examine histopathologic alterations in the gills of Nile tilapia (Oreochromis niloticus) to determine possible effects of lead (Pb), carbon nanotubes, and Pb+carbon nanotubes on their histological integrity, and if this biological system can be used as a tool for evaluating water quality in monitoring programs. For this, tilapia were exposed to Pb, carbon nanotubes and Pb+carbon nanotubes for 4 days. The main alterations observed were epithelial structure, hyperplasia and displacement of epithelial cells, and alterations of the structure and occurrence of aneurysms in the secondary lamella. The most severe alterations were related to the Pb+carbon nanotubes. We conclude that the oxidized multi-walled carbon nanotubes enhanced the acute lead toxicity in Nile tilapias. This work draws attention to the implications of carbon nanomaterials released in the aquatic environment and their interaction with classical pollutants.