Search

Photocatalysts based on g-C3N4 have been investigated in the CO2 reduction reaction under visible light irradiation (λ = 397, 427, 452 nm). Photocatalysts were prepared by melamine calcination at 500–600 °C with further platinum deposition (0.1–1.0 wt.%). The effect of the preparation conditions of g-C3N4 and the method of platinum deposition on the physicochemical properties and activity of photocatalysts was studied. The photocatalysts were investigated by X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, X-ray diffraction, high resolution transmission electron microscopy, UV-Vis spectroscopy, and low temperature nitrogen adsorption techniques. It has been found that the efficiency of CO2 reduction is governed by the surface area of g-C3N4 and the presence of platinum in the metallic state, while the optimal content of platinum is 0.5 wt. %. The highest rate of CO2 reduction achieved over Pt/g-C3N4 photocatalyst is 13.2 µmol h−1 g−1 (397 nm), which exceeds the activity of pristine g-C3N4 by 7 times. The most active photocatalysts was prepared by calcining melamine in air at 600 °C, followed by modification with platinum (0.5 wt.%). [ABSTRACT FROM AUTHOR]

Different long-chain primary alkylamines such as octylamine, dodecylamine, tetradecylamine, hexadecylamine or octadecylamine were used to stabilize Ni-NiO nanoparticles (metal:stabilizer ratio of 1:10) by an organometallic method in organic medium to evaluate their effect on the microstructural and magnetic properties. The Ni-NiO stabilized nanoparticles were characterized by Fourier transformed infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), conventional transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and dynamic light scattering (DLS). The results indicated an adequate stabilization of Ni nanoparticles with the different primary alkylamines. The semi-quantitative analysis suggests that Ni surface composition is a combination of the metallic state with NiO, NiOOH and NiO, but the chain length modified the content and proportion of these compounds. The highest Ni metallic state (57.2 at. %) was obtained with tetradecylamine as stabilizer. The morphology of the samples is similar to a core–shell semi-spherical, but the particle size tends to reduce with the alkyl chain length of primary amines from 20 to 8 nm. The saturation magnetization (Ms) showed important variations depending on the surface composition, for which variable particle size and Ni metallic content were determining factors for the magnetic response. [ABSTRACT FROM AUTHOR]

Different concentrations (2 and 4 wt%) of graphite carbon nitride (g-C 3 N 4) was doped into fixed amount of chitosan (CS) and nickel oxide (NiO) nanoparticles (NPs) via a co-precipitation route. The aim of study is to remove the pollutants from wastewater through catalytic activity (CA) and determine the bactericidal activities of synthesized products. X-ray diffraction pattern confirmed the cubic structure of NiO NPs and peak shifted to higher angle upon g-C 3 N 4 doping. Fourier transform infrared spectroscopy revealed the existence of bending and stretching vibration mode. The absorption decreased gradually accompanied blue-shift and assessed bandgap energy increased upon doping. The high resolution transmission electron microscopy micrographs confirmed the formation of cubic-shaped NPs and elongated nanorods were seen for NiO and co-doped NiO. The catalytic efficiency of samples was examined using methylene blue (MB) in the presence of reducing agent. A remarkable dye de-colorization was confirmed with a g-C 3 N 4 and CS doping; moreover, the bactericidal efficacy compared to Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was observed as 3.15 and 13.8 mm, respectively. In silico, molecular docking investigations targeting against b-lactamase S. aureus and FabH E. coli enzymes assisted to elaborate the mechanism underlying microbicidal action of the NPs. [ABSTRACT FROM AUTHOR]

The Pt-containing commercial mordenite catalyst that was synthesized having different Si/Al molar ratios (SAR) = 32, 40, and 50, and it was applied in the epoxidation reaction of cyclohexene. The samples were analysed and confirmed by various physicochemical techniques in powder X-ray diffraction (XRD) for identifying phases and planes, Brunauer-Emmett-Teller (BET) for determining textural properties, Fourier-transform infrared spectroscopy (FT-IR) for distinguishing functional groups, high resolution scanning electron microscopy (HR-SEM) for finding morphology, temperature-programmed desorption (TPD) to determine stability, and transmission electron microscopy (TEM) to identify microstructural details. The catalysts were tested for cyclohexene epoxidation reaction in the presence of H 2 O 2 as oxidant and acetonitrile as solvent. In this work, cyclohexene maximum conversion and selectivity is obtained with Pt/mordenite (40%) catalyst among the catalysts investigated. The conversion of cyclohexene oxidation recyclability of the Pt/Mordenite (40%) reveals reasonably acceptable conversion efficiency after six cycles, and the catalyst is found to be most suitable for an industrial production application. [Display omitted] • The commercial mordenite zeolite was dealuminated successfully by acid leaching method. • The BET, SEM and TEM confirms the enhanced textural properties and suitable morphology of mordenite (40) support. • Highly effective Pt/mordenite catalyst for cyclohexene oxidation. • Higher conversion and selectivity were seen over Pt/mordenite (40) catalyst for the cyclohexene oxidation at 90 °C. [ABSTRACT FROM AUTHOR]

Nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) are widely used for drug delivery. One of the main challenges is to clarify their interaction with hypoxia-inducible factor 1 alpha (HIF-1α), the lack of which leads to oncological and cardiovascular diseases. In the presented study, N-MWCNTs were synthesized by catalytic chemical vapor deposition and irradiated with argon ions. Their chemical state, local structure, interfaces, Stone–Wales defects, and doping with nitrogen were analyzed by high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Using experimental data, supercells of functionalized N-MWCNTs with an oxygen content of 2.7, 4 and 6 at. % in carboxyl groups were built by quantum chemical methods. Our analysis by the self-consistent charge density functional tight-binding (SCC DFTB) method shows that a key role in the functionalization of CNTs with carboxyl groups belongs to Stone–Wales defects. The results of research in the decoration of CNTs with HIF-1α demonstrate the possibility of wave-diffusion drug delivery. The nature of hybridization and relaxation determines the mechanism of oxygen regulation with HIF-1α molecules, namely, by OH-(OH–C) and OH-(O=C) chemical bonds. The concentration dependence of drug release in the diffusion mode suggests that the best pattern for drug delivery is provided by the tube with a carboxylic oxygen content of 6 at. %. [ABSTRACT FROM AUTHOR]

Lanthanum doped magnesium-zinc spinel ferrite samples were synthesized by the simple co-precipitation method with composition M g 0.5 Z n 0.5 F e 2 − x L a x O 4 (x = 0,0.025,0.05,0.075 a n d 0.1). The synthesized ferrite samples were investigated using by powder X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM) coupled with energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HR-TEM), electron paramagnetic resonance spectroscopy (EPR) and vibrating sample magnetometer (VSM). The effect of the La3+ ion doping on the crystallite size and lattice parameter of the material has been discussed. The crystallite size for all the samples were found to be in the range of 7–12 nm. The percentage porosity and percentage crystallinity of all the samples were found to be in the range of 49–50% and 80–85% respectively. In the frequency region of 400–600 cm−1 two absorption bands attributed to the T d and O h sites of the spinel ferrite have been observed. FTIR band spectra shift from lower to higher region with La3+ ion doping. Agglomeration of the particles is observed in the FE-SEM and HR-TEM images. Additional impurities except carbon are not present in the sample which is confirmed by EDS analysis. EPR analysis shows a decrease in the g-value from 2.18 to 2.12 for the synthesized samples with La3+ ion doping. The resonance field for synthesized sample shifts to higher magnetic field which may be due to ferromagnetic interaction caused by La3+ ion doping. The maximum spin concentration (1.508 × 1021 spin/g) and the relaxation time (4.132 × 10−11 s−1) was observed for the MZL2 composition. Magnetization curve shows the typical superparamagnetic nature of synthesized samples. The calculated squareness value of the synthesized sample refers to the magnetostatic interaction among particles. The obtained coercive field value is low which makes these materials suitable for ferrofluids and hyperthermia treatment applications. [ABSTRACT FROM AUTHOR]

In this research, we have presented detailed studies of the effect of temperature-controlled hydrothermal fabrication techniques on the morphology and structural strain in magnetoelectric core-shell nanocomposite having magnetic CoFe2O4 core coated with a piezoelectric BaTiO3 shell. We have presented the effect of controlled cooling rate during annealing process of synthesis on the structural integrity and structural strain of the core-shell hetero-nanostructure. Using temperature controlled hydrothermal method, it has been observed that controlling the cooling rate to 20 °C/min while annealing process leads to low structural strain on the deposited BaTiO3 shell. This also leads to high structural integrity of the fabricated heterostructure nanocomposite. To measure the strain distribution in the coated shell, geometric phase analysis was performed on the high-resolution transmission electron microscopic image of the fabricated core-shell nanostructure. Semi quantitative Energy-dispersive X-ray spectroscopy line scan elemental mapping have confirmed the elemental distribution throughout the nanostructure and formation of the core–shell structure. Moreover, through the geometric phase analysis, the core and the shell can be distinctively visualized which confirms the homogeneity of the coating of single crystalline BaTiO3 shell on the CoFe2O4 core. [ABSTRACT FROM AUTHOR]

Recently, SnSe based thermoelectric materials attained much interest due to their environment friendly IV–VI semiconductor group. Herein, Al doped SnSe (Sn1−xAlxSe) specimens were prepared by combined ball milling and spark plasma sintering. High resolution transmission electron microscopy analysis of (Sn1−xAlxSe) nanostructure samples confirmed the existence of different crystal defects and dislocation induced by Al doping. Lower thermal conductivity (0.63 W/mK at 750 K) is observed for Sno.92Al0.08Se samples than pristine SnSe (1.14 W/mK at 750 K), which is mainly attributed to various crystal defects, such as lattice dislocation, stacking fault, grain boundary scattering, and excellent anharmonic bonding nature of SnSe. The maximum electrical conductivity is observed for the SAS-2 sample, which correlates well with the low activation energy of 0.20 eV. The minimal doping of Al (SAS-2) decoupled the strong interdependency of electrical and thermal transport properties, leading to a maximum ZT of 0.18 at 743 K. The Al doped SnSe (Sn1−xAlxSe) induced point defects in the sample, which provides a new strategy for waste heat recovery. [ABSTRACT FROM AUTHOR]

The microstructure evolution and precipitation behavior of Al-Mg-Si alloy during initial aging were studied using hardness testing, conductivity testing, differential scanning calorimetry (DSC), and high resolution transmission electron microscopy (HRTEM). The results show that the precipitation sequence of the Al-Mg-Si alloy during initial aging can be represented as: supersaturated solid solution → spherical Mg/Si clusters → needle-like Guinier Preston (GP) zone → β". Clusters are completely coherent with the Al matrix. The GP zone with relatively complete independent lattice parameters that differ slightly from the Al matrix parameters, is oriented along the direction of <111>Al and lying on {111}Al plane. The strength of the Al-Mg-Si alloy is greatly enhanced by the threedimensional strain field that exists between the β" phase and the two {200}Al planes. After aging at 170 °C for 6 h, the hardness reaches the peak of 127 HV and remains for a long time. At this stage, the electrical conductivity keeps relatively stable due to the formation of coherent precipitates (Mg/Si clusters/GP zones) and the reduction in solute atom concentration in the Al matrix. The severe coarsening and decreased number density of the β" phase during the over-aging stage result in a significant decrease in the hardness. [ABSTRACT FROM AUTHOR]

In this work, a magnetically separated photocatalyst with great efficiency CuCe-Ferrite/TiO2 composite was prepared and characterized by X-ray diffraction (XRD), UV–Vis spectrophotometry, Fourier transformer infra-red spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometer (VSM). Single-phase cubic spinel was formed by calcining the prepared sample at a temperature of 550 °C, according to the results. Different concentrations of reactive red 250 (RR250) dye photodegradation was evaluated using different doses of CuCe-ferrite/ TiO2 and TiO2 NPs. Higher efficiency of RR250 photodegradation up to 100% was obtained using CuCe-ferrite/ TiO2. The photodegradation efficiency was confirmed using chemical oxygen demand (COD) test of both treated and untreated samples. The oxidation process was mostly mediated by photogenerated .O2− according to scavenger test results. The catalyst possess higher photodegradation efficiency even after regeneration for ten times. [ABSTRACT FROM AUTHOR]

We report the synthesis of graphene oxide/nickel oxide/β-cyclodextrin (GO/NiO/β-CD) nanocomposite and the efficiency of the nanocomposite in decolourising two different dyes, methylene blue (MB) and methyl violet (MV). GO was prepared by modified Hummer's method while hydrothermal method was used for the preparation of GO/NiO/β-CD. The as-synthesised nanocomposites were characterised by X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and high resolution transmission electron microscopy (HR-TEM). Photocatalytic degradation was carried out under solar light by monitoring the concentration of MB and MV dyes. Degradation reaction followed Langmuir-Hinshelwood pseudo first-order kinetic model. The apparent reaction rate constant (k) for MB increased as compared to MV under solar light irradiation. The MB showed better photocatalytic degradation efficiency by GO/NiO/β-CD composites. GO/NiO/β-CD nanocomposite has been very favourable for photocatalytic application. [ABSTRACT FROM AUTHOR]

Membrane distillation (MD) is an emerging technology for water recovery from hypersaline wastewater. Membrane scaling and wetting are the drawbacks that prevent the widespread implementation of the MD process. In this study, coaxially electrospun polyvinylidene fluoride-co-hexafluoropropylene (PVDF-co-HFP) nanofibrous membranes were fabricated with re-entrant architecture and enhanced hydrophobicity/omniphobicity. The multiscale roughness was constructed by incorporating Al2O3 nanoparticles and 1H, 1H, 2H, 2H Perfluorodecyltriethoxysilane in the sheath solution. High resolution transmission electron microscopy (HR-TEM) could confirm the formation of the core-sheath nanofibrous membranes, which exhibited a water contact angle of ~142.5° and enhanced surface roughness. The membrane displayed a stable vapor flux of 12 L.m−2.h−1 (LMH) for a 7.0 wt.% NaCl feed solution and no loss in permeate quality or quantity. Long-term water recovery from 10.5 wt.% NaCl feed solution was determined to be 8–10 LMH with >99.9% NaCl rejection for up to 5 cycles of operation (60 h). The membranes exhibited excellent resistance to wetting even above the critical micelle concentration (CMC) for surfactants in the order sodium dodecyl sulphate (SDS) (16 mM) > cetyltrimethylammonium bromide (CTAB) (1.5 mM) > Tween 80 (0.10 mM). The presence of salts further deteriorated membrane performance for SDS (12 mM) and Tween-80 (0.05 mM). These coaxial electrospun nanofibrous membranes are robust and can be explored for long-term applications. [ABSTRACT FROM AUTHOR]

Ni nanoparticles (NiNPs) were prepared by thermal decomposition of nickel acetylacetonate in the presence of a third generation polypyridylphenylene dendrimer (G3) which acts both as a coordinating ligand due to presence of pyridine groups and as a stabilizing agent due to highly branched architecture. Transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), and X‐ray photoelectron spectroscopy (XPS) were used to extensively evaluate structure and morphology of the synthesized NiNPs@G3. The selected area electron diffraction (SAED) allowed us to conclude about fcc structure of NiNPs while STEM EDS analysis demonstrated a formation of core‐shell NiO@Ni NPs. Further, the catalyst was tested in selected Suzuki‐Miyaura cross‐coupling reactions at mild conditions and demonstrated a high efficiency at low Ni loading with negligible content of Ni0 on the NP surface. The functional hyperbranched dendrimer macromolecule provided an excellent stabilization for NiNPs@G3 while allowing an easy access for reactants to catalytic sites. The high activity of the catalyst in the recycling experiments was maintained by the absence of Ni leaching from the NiNPs@G3. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms that connect heat and electron transport with crystal structures and defect chemistry is fundamental to develop materials with thermoelectric properties. In this work, we synthesized a series of self‐doped compounds Cu2+xMn1−xGeS4 through Cu for Mn substitution. Using a combination of powder X‐ray diffraction, high resolution transmission electron microscopy and precession‐assisted electron diffraction tomography, we evidence that the materials are composed of interconnected enargite‐ and stannite‐type structures, via the formation of nanodomains with a high density of coherent interfaces. By combining experiments with ab initio electron and phonon calculations, we discuss the structure–thermoelectric properties relationships and clarify the interesting crystal chemistry in this system. We demonstrate that excess Cu+ substituted for Mn2+ dopes holes into the top of the valence band, leading to a remarkable enhancement of the power factor and figure of merit ZT. [ABSTRACT FROM AUTHOR]

Nanostructured MFe 2 O 4 (M = Co and Zn) ferrites have been successfully synthesized by hydrothermal method using cetyltrimethylammonium bromide (CTAB) as a surfactant and ammonium hydroxide (NH 4 OH) as a precipitating agent at a moderate temperature (∼160 °C) for 10 h and subsequent calcination of the precursors at 400 and 600 °C. These ferrite materials have been characterized by X-ray diffraction (XRD), BET surface area, scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), thermogravimetric analysis−differential scanning calorimetry (TGA−DSC), Fourier transformed infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The CoFe 2 O 4 is found to have both hexagonal and spherical surface morphologies and for ZnFe 2 O 4 a spherical morphology is obtained at 600 °C. Optical, dielectric, and magnetic properties of these ferrites have been investigated. CoFe 2 O 4 exhibits ferromagnetism at room temperature. In contrast, ZnFe 2 O 4 shows paramagnetism at room temperature. The M s and H c values are observed to increase, respectively, from 74.2 emu g−1 to 78.9 emu g−1 and 1221 Oe to 1411 Oe for CoFe 2 O 4 as the calcination temperature increases from 400 °C to 600 °C. This is related to better crystallinity because of calcination at higher temperature. Dielectric properties of the ferrite materials are also enhanced with the increase in the calcination temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • First report on C-dots derived from beetroot and Fabrication of 0D/0D C-dots@CdS heterostructured photocatalysts. • C-dots@CdS showed superior activity with H 2 evolution rates of 1582 µmolg−1 than the pristine CdS (849 µmolg−1). • Achieved 97.3 % degradation efficiency of CV dye under visible light for C-dots@CdS. • The presence of C-dots in heterojunction increases the charge carrier separation leading to highest photocatalytic activity. Carbon dots (C-dots) developed from beetroot is used for the rational design of cadmium sulphide based heterojunction photocatalysts (C-dots@CdS) using hydrothermal technique. The crystal structure, phase, morphology and optical characteristics of the synthesised materials are determined using X-ray diffraction (XRD), High resolution transmission electron microscopy (HR-TEM), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–Visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL spectroscopy), BET adsorption, X-ray photoelectron spectroscopy (XPS) and electrochemical studies. Using C-dots@CdS catalytic system, a superior photocatalytic activity relative to the undecorated CdS is observed. Among the C-dots@CdS samples, the CdS loaded with 6 wt% of C-dots exhibited enhanced hydrogen evolution rate compared with other samples considered for the study. CdS nanospheres modified with C-dots (6 wt%) resulted in the photocatalytic hydrogen evolution rate of 1582 µmolg−1 against 849 µmolg−1 evolution rate obtained for CdS nanospheres within 3 h. In spite of being 0D/0D type nano-heteroarchitecture, C-dots@CdS system obtained an apparent quantum yield of 6.37 % for the catalytic dosage of 20 mg under the irradiation of visible light. CdS in the C-dots@CdS system serves as the light harvester while C-dots with discernible edges can maintain the continuous supply of photo-excited charge carriers and hence can reduce the charge-carrier recombination. Further, the photodegradation of crystal violet dye using the optimised dosage of C-dots@CdS-6 exhibited an efficiency of 97.3 % in 120 min of visible light irradiation under neutral conditions. The detailed kinetic study reveals that the mechanism of photodegradation of crystal violet dye using C-dots@CdS system can be described using pseudo-second-order kinetics. The presence of oxygen rich hydrophilic surface functionalities of C-dots, the formation of near-surface heterojunction and the suitable band structure of C-dots@CdS system leading to the optimum charge carrier separation kinetics can be attributed to the enhanced photocatalytic performance. This work offers a promising strategy to develop bio-derived C-dots based heterojunction photocatalyst to address the burgeoning energy and environmental demands. [ABSTRACT FROM AUTHOR]

In order to prepare the heterogeneous catalyst, phosphotungstic acid (PTA, H3PW12O40) and K+ were supported over silica matrix for simultaneous transesterification as well as esterification of waste cooking oil (WCO). The catalyst structure was determined by powder X-ray diffraction (XRD) analysis. The composition and the elemental oxidation state were analyzed by X-ray photoelectron spectroscopy (XPS) study, while the surface morphology was recognized by the high resolution transmission electron microscopy (HR-TEM). The presence of acidic as well as basic sites over the catalyst surface was studied by the temperature programmed desorption (TPD) technique. PTA, being acidic, is expected to provide the esterification while potassium oxide is responsible for the transesterification activity of the catalyst. In order to optimize the biodiesel yield, the effect of various reaction parameters was studied. At a 10 wt % catalyst content relative to oil, 12 : 1 methanol to oil molar ratio and 65°C reaction temperature, 98% fatty acid methyl ester (FAME) yield was obtained within 3 h of reaction duration. The catalyst was recovered via centrifugation from the reaction mixture and recycled during 6 consecutive runs. The metal concentration in the reaction mixture was found to be less than 2 ppm to verify the catalyst stability. Moreover, the catalyst was found to be effective even in the presence of high free fatty acid (up to 8.8 wt %) and moisture (up to 4 wt %) contents to prove its usefulness for biodiesel production even from low-quality vegetable oils. The kinetic modeling analysis showed that the reaction of waste oil with the prepared catalyst followed a first-order kinetics and was temperature dependent. Using the Arrhenius equation, activation energy and frequency factor were found to be 33.7 kJ/mol and 26.0 s–1 respectively. The prepared biodiesel fuel fulfill the parameters stipulated as per EN 14214 standard. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The manufacturing of silver nanoparticles (AgNPs) is now safer, more economical, nontoxic, and environmentally benign thanks to the extraction of Cirsium japonicum. The extracts from C. japonicum worked as a stabiliser and reducer. AgNP synthesis was verified by UV/Vis spectroscopy. There have been studies done on the production of AgNP at various temperatures and concentrations. Their dispersion was validated by high resolution transmission electron microscopy (HRTEM), which also revealed their tiny (2-8nm) spherical form, lack of aggregation, and spherical shape. AgNPs were found to be crystalline using X-ray diffraction (XRD). Using EDX, it was possible to determine the substance's elemental makeup. FTIR spectroscopy was used to identify the chemical molecules that coat AgNPs. The photodegradation of bromo phenyl blue has been investigated in a variety of settings, including experimental setups and catalyst size and structure. In about 12 min, 98 percent of the bromo phenyl blue was destroyed using AgNPs as photo catalysts. Water purification and the transformation of organic hazardous substances into non-hazardous products are obvious uses for AgNPs due to their powerful reductive capabilities. Amazing electro-catalytic abilities for hydroquinone were shown by the electrode (Ag/GC) that was transformed to AgNPs. In an acetate buffer solution, the cyclic voltametric analysis of AgNPs was examined. The experiment findings for GC and modified AgNPs were contrasted. The conductivity of AgNPs was investigated in an acetate buffer solution with a 0.15 M concentration. The generated AgNPs are uniform in size and stability. The produced AgNPs' electrochemical potential was shown. [ABSTRACT FROM AUTHOR]

Reinforcement of aluminum and aluminum alloys with graphene has been intensively practiced by researchers in the past dozen years. The role of Al4C3, which could be produced unintentionally or purposefully during the composite production, was controversial until it was found that nano-sized carbides were beneficial for strengthening the composites. aluminum-graphene-nano-sized Al4C3 composites were produced by us using the powder metallurgical method and subsequent annealing. The microstructure was investigated using light microscopy (LM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and high resolution transmission electron microscopy HRTEM. Nano-sized carbides were found at the interface aluminum-graphene. The formation of a chemical bond between aluminum and graphene during annealing was proved. Lower values of the microhardness and strength characteristics of the composites after extrusion and subsequent annealing during which nano-sized carbides are formed were found in comparison with those obtained after extrusion. It could be supposed that the annealing processes contribute more to the reduction in microhardness and strength characteristics than nano-sized carbides contribute to its increase. The presence of a strong chemical bond between the graphene and the aluminum is manifested in the failure pattern, which is characterized by graphene nano-platelets and nano-sized carbides fracture and semi-pulled out or semi-slipped Al4C3 from the matrix. [ABSTRACT FROM AUTHOR]

Diagnosis and monitoring of glucose level in human blood has become a prime necessity to avoid health risk and to cater this, a sensor's performance with wide linearity range and high sensitivity is required. This work reports the use of ternary composite viz. MG–Cu2O (rGO supported MXene sheet with Cu2O) for non-enzymatic sensing of glucose. It has been prepared by co-precipitation method and characterized with X-ray powder diffraction, Ultraviolet–visible absorption spectroscopy (UV–Vis), Raman spectroscopy, Field emission scanning electron microscopy, High resolution transmission electron microscopy and Selected area diffraction. These analyses show a cubic structure with spherical shaped Cu2O grown on the MG sheet. Further, the electrocatalytic activity was carried out with MG–Cu2O sensing element by cyclic voltammetry and chronoamperometry technique and compared with M–Cu2O (MXene with Cu2O) composite without graphene oxide. Of these, MG–Cu2O composite was having the high defect density with lower crystalline size of Cu2O, which might enhance the conductivity thereby increasing the electrocatalytic activity towards the oxidation of glucose as compared to M–Cu2O. The prepared MG–Cu2O composite shows a sensitivity of 126.6 µAmM−1 cm−2 with a wide linear range of 0.01to 30 mM, good selectivity, good stability over 30 days and shows a low Relative Standard Deviation (RSD) of 1.7% value towards the sensing of glucose level in human serum. Thus, the aforementioned finding indicates that the prepared sensing electrode is a well suitable candidate for the sensing of glucose level for real time applications. [ABSTRACT FROM AUTHOR]

In the present work, Cu-doped ZnO nanostructures (Cu% = 0, 1, 5) have been prepared using microwave-assisted chemical route synthesis. The synthesized nanostructures were investigated through structural, morphological, optical, and magnetic characterizations. The results of the X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and selective area electron diffraction (SAED) patterns confirmed that all of the samples exhibit the single-phase polycrystalline hexagonal crystal structure. The XRD results infer a decrease in the lattice parameters (a/c) by increasing the Cu% doping into ZnO. The field emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray (EDX) spectroscopic measurements revealed the formation of nanostructures, showing the major elemental presence of Zn and O in the samples. The photoluminescence (PL) spectra exhibited photoemission in the UV and blue-green regions. With the increase in the Cu%, the photoemission in the UV region is reduced, while it is enhanced in the blue-green region. Raman spectra of the Cu-doped ZnO nanostructures displayed a blue shift of the E 2 High mode and an increase in the peak intensity of E1(LO), indicating the doping of Cu ion in the ZnO lattice. The dc magnetization measurements demonstrated the ferromagnetic behavior of all of the samples with an enhanced ferromagnetic character with increasing Cu%. [ABSTRACT FROM AUTHOR]

Herein, a series of 5NixHo/YZr (x = 1, 2, 3, 4, 5 wt%) materials, never reported before, were tested in DRM reaction and characterized using several techniques like Nitrogen physisorption, X-ray diffraction, UV–vis and RAMAN spectroscopies, High Resolution Transmission Electron Microscopy, H 2 -Temperature Programmed Reduction, CO 2 -Temperature Programmed De-adsorption and Thermogravimetry. The incorporation of Yttria in the structure modifies pore sizes and stabilizes cubic Zirconia phases, whereas the addition of Ho as a promotor brings stable cubic zirconia, stable cubic holmium zirconium oxide phase and a wide range of reducible NiO-interacted species. In particular, an optimum Ho loading of 4 wt%, characterized by a minimum bandgap, strong suppression of RWGS reaction and maximum amount of reducible NiO-interacted species allows to achieve 84.1% H 2 yield and 84.1% CO yield constantly over 420-min time on stream. The least basic sites availability over 5Ni5Ho/YZr results into inferior catalyst performance. [Display omitted] • 5NixHo/YZr (x = 0–5 wt%) materials is reported first time and found Highly affective in DRM. • 5Ni/YZr has rich basic profile but unstable monoclinic ZrO 2 phase which results into 44% H 2 -yield. • Ho presence nurtures stable cubic holmium zirconium oxide phase & wide range reducible NiO-species. • 5Ni4Ho/YZr catalyst is characterized by minimum bandgap & maximum reducible NiO-species. • 1 wt%Ho, 2 wt%Ho, 3 wt%Ho and 2 wt%Ho show 74.6%, 76%, 78.58% and 84.1% H 2 yield respectively. [ABSTRACT FROM AUTHOR]

Ion implantation induced phase transformation and the crystal structure of a series of ion implanted β-Ga2O3 samples were studied using electron diffraction, high resolution transmission electron microscopy, and scanning transmission electron microscopy. In contrast to previous reports suggesting an ion implantation induced transformation to the orthorhombic κ-phase, we show that for 28Si+, 58Ni+, and stoichiometric 69Ga+/16O+-implantations, the monoclinic β-phase transforms to the cubic γ-phase. The γ-phase was confirmed for implantations over a range of fluences from 1014 to 1016 ions/cm2, indicating that the transformation is a general phenomenon for β-Ga2O3 due to strain accumulation and/or γ-Ga2O3 being energetically preferred over highly defective β-Ga2O3. [ABSTRACT FROM AUTHOR]

The adsorption-enhancing TiO2-SBA-15 photocatalyst has been synthesized by an in situ etching displacement method, which possesses unique regular hexagonal pores and large specific surface area. The as-prepared TiO2-SBA-15 can effectively adsorb and increase the concentration of pollutants in the photocatalyst and collision likelihood with the photogenerated radicals, thus improving the efficiency of photocatalytic organic degradation. The structure and morphology have been characterized by N2 adsorption isotherms, X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and scanning electron microscopy (SEM). These characterizations confirm that TiF4 alcohol solution prefers to react with the internal surface of SBA-15 because of the Siphon effect. Fourier transform infrared (FTIR) spectra demonstrate that a Ti-O-Si bond formed after the reaction of TiF4 with SBA-15, which reveals a wonderful combination of TiO2 and SiO2 even at low temperatures. Through this function, the nanocomposite TiO2-SBA-15 could obviously improve the efficiency of photocatalytical removal of toluene in the gas phase. [ABSTRACT FROM AUTHOR]

This paper demonstrates a low-temperature solvothermal method of nitrogen-rich covalent organic framework (COF) onions. The atomic structure and the bonding features are revealed by high resolution transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS). The novel COF onion provides potential applications in photocatalysts considering its suitable bandgap value of 2.56 eV. [Display omitted] Achieving hierarchical nanomaterials from a bottom-up approach remains challenging. Here, we report a closed-cage, onion nanostructure of covalent organic framework (COF) obtained through a low-temperature solvothermal synthesis. Atomic resolution transmission electron microscopy revealed the atomic arrangement in this COF onion, in which rich nitrogen was uniformly embedded in the periodic porous graphitic framework. The COF onion structure displayed graphitic features at a 0.33 nm interlayer spacing with Van der Waals interactions predominated between the layers. The onion layers exhibited significant heterogeneity in layer stacking by adopting a combination of different stacking modes. Defects were also found, such as five- or seven-member rings deviating from the perfect hexagonal lattice. These geometrical defects resulted in curving the 2D layers, which may have promoted the formation of onion nanostructures through a layer-by-layer attachment. We constructed a corresponding model that predicts COF onion properties. This novel onion exhibited a bandgap value of 2.56 eV, resembling other carbon-based nanomaterials, suggesting potential applications in sensors, photocatalysts, and nanoelectronics. [ABSTRACT FROM AUTHOR]

Ceramic diffusion barrier coatings are inevitable in high temperature aerospace and nuclear applications to protect superalloys from oxidation and hot corrosion. Compositionally graded coating (CGC) of Ni-YSZ with five layers was deposited on an Inconel-690 substrate through electron beam physical vapor deposition (EBPVD) method. After heat treatment, the phase formation and crystallite determination in each layer of the CGC were studied by X-ray diffraction. Pulsed radio frequency glow discharge optical emission spectroscopy (RF-GDOES) showed outward diffusion of Ni towards the surface of the CGC. High resolution transmission electron microscopy (HRTEM) studies of the cross-sectional region of the heat-treated coating at 1273 K revealed no secondary phases within the coating as well as at substrate-coating interface. The corrosion behavior of Ni-YSZ coating under 3 M HNO 3 medium showed that the heat-treated CGC of Ni-YSZ exhibited better corrosion resistance due to the formation of NiO than as-deposited Ni-YSZ coating. [ABSTRACT FROM AUTHOR]

A novel 2‐D flakes like Al‐BPED ((N1,N2‐bis [pyridine‐2‐yl]methyl)ethane‐1,2‐diamine) metal–organic framework (MOF) have been explored for its catalytic potential in the N‐alkylation of amines with dialkyl carbonates. The Al‐BPED MOF catalyst has been synthesized by hydrothermal route. The X‐ray diffraction, Fourier Transform Infrared Spectroscope (FTIR), and High Resolution Transmission Electron Microscopy (HRTEM) images were used to analyze the morphology of the synthesized Al‐BPED MOF samples. With the use of Al‐BPED MOF, the primary and secondary aromatic amines were selectively and efficiently methylated with dimethyl carbonate. The effect of process conditions has been investigated toward N‐methylation, N‐ethylation, and N‐benzylation of aromatic amines. Under the optimal conditions with 10 mol% of the MOF catalyst, a maximum aniline conversion of 88% and a selectivity >90% toward N‐alkylation was achieved. The kinetic studies revealed the N‐alkylation reaction in presence of Al‐BPED MOF followed pseudo‐first order rate kinetics. [ABSTRACT FROM AUTHOR]

The carbon-based composite materials prepared through green synthetic approach are attracting greater interest in electrochemical applications due to their sustainable nature. Herein, we developed Fe 2 O 3 and Fe 2 O 3 @CNT composite materials via a green mechanochemical one-pot method. The as prepared composite materials were characterized by X-ray diffraction (XRD), energy dispersive X-Ray spectroscopy (EDS), field emission scanning microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS), respectively. Incorporating Fe 2 O 3 nanoparticles on CNT surface tunes its electronic structure as well increases active sites and thus enhance the oxygen evolution reaction (OER) performance. As a result, the fabricated Fe 2 O 3 @CNT is a highly effective and balanced electrocatalyst that delivers superior current density (j = 10 mA cm−2) at low overpotential (η = 270 mV) for OER compared with pristine Fe 2 O 3 (η = 290 mV) in 1 M KOH. Further, Fe 2 O 3 @CNT electrocatalyst shows high long-term durability in 1 M KOH for 100 h, fulfilling all the advantageous viable standards for OER. [ABSTRACT FROM AUTHOR]

In this research work, Ni–P–Bi 2 O 3 nanocomposite coatings are fabricated on mild steel via an effective galvanostatic electrodeposition method. The fabricated coating properties such as texture coefficient, morphology, composition, microhardness, and corrosion prevention characteristics are examined with X-ray diffraction, high resolution scanning electron microscopy, energy dispersive spectroscopy, Vicker's hardness method, and potentiodynamic polarization techniques, respectively. Mechanistic analysis denotes that the encapsulation of Bi 2 O 3 nanoparticles increases the microhardness value of the Ni–P–Bi 2 O 3 nanocomposite coatings. Potentiodynamic polarization and electrochemical impedance spectroscopy tests have been examined in 3.5 wt% NaCl solution and the results emphasize that the corrosion resistance of Ni–P–Bi 2 O 3 nanocomposite coatings is significantly enhanced when compared to electrodeposited Ni, Ni–P, and Ni–Bi 2 O 3 coatings. [ABSTRACT FROM AUTHOR]

The development of bimetallic and magnetic nanomaterials as a catalyst is highly desirable for organic transformations due to their recyclability for the sustainable future of chemical industries. Bimetallic CoNi nanoflowers were developed via the facile liquid‐phase reduction method and were employed for the hydrogenation of terminal alkynes. The structural and morphological studies were analyzed by X‐ray diffraction, Field‐Emission Scanning Electron Microscopy, and High Resolution Transmission Electron Microscopy. The bimetallic CoNi nanoflower exhibited 100 % conversion with ∼100 % selectivity towards alkane products with recyclability up to six cycles. The transfer hydrogenation mechanism was proposed via diimide formation with Co(0)/Ni(0) state, confirmed by X‐ray Photoemission Spectroscopy analysis. [ABSTRACT FROM AUTHOR]

Aluminum nitride (AlN) films with low defect concentration were fabricated on Si substrates via RF magnetron sputtering system based on Al-rich AlN (Al-AlN) targets. The effects of Al-rich content on structure, defects and photoelectric properties of AlN films were investigated by x-ray diffraction (XRD), high resolution transmission electron microscopy, x-ray photoelectron spectroscopy (XPS), low temperature photoluminescence (PL), ultraviolet-visible spectra, currentâ€"voltage (I â€" V) and capacitanceâ€"voltage (C â€" V) characteristics. In particular, the defects of AlN films were investigated by XPS and low-temperature PL analyses, indicating that Al-rich AlN targets can help to reduce the defects of Al vacancy and O impurity of AlN films with an optimal Al-rich content of 1.5 wt. % (A1.5). Schottky contact behavior between AlN films and Ti/Al/Ni/Au multi-layer electrodes were revealed from I â€" V curves of all samples based on parallel electrodes, and AlN metal-semiconductor-metal (MSM) devices prepared by A1.5 films exhibited the lowest leakage current of 2.43 Ă— 10âˆ'8 A at the bias of 5 V. C â€" V tests indicate the less defect density and lower carrier concentrations of vertical structure of A1.5 devices. This work offers a feasible approach to regulate the defects of AlN films for practical application. [ABSTRACT FROM AUTHOR]

Azithromycin is one of the most concentrated antibiotics in wastewater, as conventional wastewater treatment facilities cannot eliminate this antibiotic from the environment. In this study, we proposed using a graphene-based mesoporous electrochemical sensor to take simultaneous voltammetric measurements of azithromycin. Because of its homogeneous pore structure, large surface area, quick electron transfer rate, and superior biocompatibility, magnesium-containing mesoporous silica is a promising resource for the immobilization of biomolecule matrix. Ca2+-doped MgAl2O3-G-SiO2 was used to build an amperometric biosensor through a self-assembly process. At room temperature in a buffer solution with a pH of 7.0, the modified electrode under ideal circumstances displayed good azithromycin sensing activity, a linear range of 1 to 5 µmolL−1, a detection limit of 0.5 µmolL−1, and a reaction time of less than 2 sec. An array of morphological analysis methods—including X-ray diffraction methos, scanning electron microscopy, Brunauer-Emmett-Teller method, high resolution tunneling electron microscopy, Raman, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy—was used to examine the nanocomposite's crystalline structure. Cyclic voltammetry was used to determine the sensing effects in the mesoporous active nanomaterials. Finally, it was found that the electrochemical sensor performed as an ideal biosensor that was able to detect azithromycin in the presence of several interfering species with high stability, selectivity, and repeatability. [ABSTRACT FROM AUTHOR]

In spite of advanced research on functional colloidal inorganic nanoparticles and their reactivity, room temperature reactive interactions between two different colloids have remained challenging so far. Laser ablation of titanium monoxide and silicon monoxide in ethanol and water allows the generation of TiO-derived and SiO-derived colloidal nanoparticles which were characterized for their stability, size distribution and zeta potentials with dynamic light scattering and after evaporation of solvent examined for their morphology, chemical and phase composition by scanning electron microscopy, Raman spectroscopy, high resolution transmission electron microscopy and electron diffraction and small angle X-ray scattering. Aqueous and ethanolic TiO-derived colloids consist of anatase and monoclinic TiO, while ethanolic SiO-derived colloids are composed of crystalline and amorphous Si, nanocrystalline Si and SiO2 and aqueous SiO-derived colloids contain, in addition to these phases, a high pressure form of cristobalite. Simple room temperature mixing of ethanolic TiO- and SiO-derived colloids allows the formation of TiSi2, which is a case of so far unreported room temperature reactive interactions between two colloidal species. All colloids absorb solar light and act as photocatalysts for methylene blue degradation. These findings present a challenge for further search for feasible room-temperature reactions between distinct colloidal particles and open the potential for green synthesis of other desirable and hardly achievable phases. [ABSTRACT FROM AUTHOR]

The nanoparticles (NP), consisting of hydrazine grafted organo-silica with PdNPs embedded shell on the Fe 3 O 4 core, were prepared to study the adsorption and interactions of hydrogen in PdNPs and their support matrix. This material is expected to find the applications in the hydrogen technology including catalysis. The PdNPs were formed spontaneously in the organo-silica shell on magnetite nanoparticles by the reduction of Pd2+ ions with grafted hydrazine in the organo-silica shell. Thus formed NPs, termed as Fe 3 O 4 -GTEOS@PdNPs, were also thermally treated at 1033 K in Ar atmosphere to convert organic components to carbon. The chemical composition, physical structure, and magnetic properties were studied by high resolution transmission electron microscopy, X-rays diffraction, Mössbauer spectroscopy and X-ray photoelectron spectroscopy for the characterizations of physical, chemical and magnetic changes occurred in the Fe 3 O 4 -GTEOS@PdNPs after hydrogen adsorption-desorption at varying temperatures with respect to that in unused one. The hydrogen adsorption pressure-composition (PC) isotherms in Fe 3 O 4 -GTEOS@PdNPs followed the expected trend from 173 to 303 K as expected from PdNPs. However, thermally treated Fe 3 O 4 -GTEOS@PdNPs were found to adsorb lower amount of hydrogen due to oxidation of Pd0 to PdO and morphological changes during heating in Ar atmosphere. The comparison of n H /n Pd value (0.49) obtained for the PdNPs in Fe 3 O 4 -GTEOS@PdNPs with the values those reported in the literature for different Pd materials showed the decrease in n H /n Pd value with decrease in the size of Pd particles. This was attributed to stronger Pd–H bond in a nanoscale palladium, which prevented hydrogen transfer to interior matrix as compared to bigger Pd particles. The hydrogen adsorption PC isotherm at 373 K in Fe 3 O 4 -GTEOS@PdNPs could not be obtained as the unknown chemical reaction happened in the sample during the experiment. The considerably higher H 2 consumption in the Fe 3 O 4 -GTEOS@PdNPs occurred at 373 K than that expected from the hydrogen adsorption in the PdNPs alone. [Display omitted] • Hydrazine grafted organo-silica shell on magnetite NP was formed to host Pd NPs. • PC isotherms for the H 2 adsorption followed normal trend in 173–303 K temp. range. • H 2 adsorption decreased in nanoscaling of Pd particles due to stronger Pd–H bonds. • Hydrogen adsorption PC isotherm at 373 K was higher than expected from Pd NPs. • Pd NPs catalyzed hydrogenation of organo-silica shell on Fe 3 O 4 occurred at 373 K. [ABSTRACT FROM AUTHOR]

Tetragonal SmVO4 nanorods were prepared by simple solvothermal route with various temperatures. An optimised SmVO4 sample was characterised through X-ray diffraction spectrum (XRD) and Micro-Raman spectroscopy. These results confirm that high crystallinity and pure tetragonal phase of SmVO4 can be achieved. For morphology analysis, scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED) techniques were performed. These results confirmed the rod shape SmVO4 nanoparticles with no impurities. For optical properties, UV-visible spectroscopy and photoluminescence (PL) techniques were performed. A broad absorption (290 nm – 330 nm) occurred in UV-Vis spectrum leads to multiple excitations and emissions at 542.7 nm, 600.5 nm and 643.7 nm with 4G5/2→6H5/2 (green), 4G5/2→6H7/2 (orange) and 4G5/2→6H9/2 (red), respectively. Finally, Vibrating sample magnetometer (VSM) study showed that the prepared SmVO4 nanoparticles possessed paramagnetic nature with high retentivity of 366.06 emu. Electrochemical performance of SV1 electrode shows pseudocapacitance nature with high specific capacitance value of 310 F/g (1 A/g) from GCD. [ABSTRACT FROM AUTHOR]

A novel chemical vapor synthesis reactor design is used to control the pore-particle mesostructure and investigate the pore formation mechanism through the variation of residence time in oxygen. This enables the exploitation of the Kirkendall effect at the nanoscale to generate ultrasmall pores in small nanocrystalline iron oxide particles. Detailed structural characterization and quantitative data analysis of complementary high resolution transmission electron microscopy images, X-ray diffractograms, nitrogen sorption isotherms and X-ray absorption spectra provide a consistent comprehensive picture of the hollow nanoparticles from the local to the microstructure. The pore formation mechanism seems to play a key role for β-Fe2O3 polymorph formation. [ABSTRACT FROM AUTHOR]

Reoviridae virus family members, such as mammalian orthoreovirus (reovirus), encounter a unique challenge during replication. To hide the dsRNA from host recognition, the genome remains encapsidated in transcriptionally active proteinaceous core capsids that transcribe and release +RNA. De novo +RNAs and core proteins must repeatedly assemble into new progeny cores in order to logarithmically amplify replication. Reoviruses also produce outercapsid (OC) proteins μ1, σ3 and σ1 that assemble onto cores to create highly stable infectious full virions. Current models of reovirus replication position amplification of transcriptionally-active cores and assembly of infectious virions in shared factories, but we hypothesized that since assembly of OC proteins would halt core amplification, OC assembly is somehow regulated. Using kinetic analysis of virus +RNA, core and OC proteins, core assembly and whole virus assembly, assembly of OC proteins was found to be temporally delayed. All viral RNAs and proteins were made simultaneously, eliminating the possibility that delayed OC RNAs or proteins account for delayed OC assembly. High resolution fluorescence and electron microscopy revealed that core amplification occurred early during infection at peripheral core-only factories, while all OC proteins associated with lipid droplets (LDs) that coalesced near the nucleus in a μ1–dependent manner. Core-only factories transitioned towards the nucleus despite cycloheximide-mediated halting of new protein expression, while new core-only factories developed in the periphery. As infection progressed, OC assembly occurred at LD-and nuclear-proximal factories. Silencing of OC μ1 expression with siRNAs led to large factories that remained further from the nucleus, implicating μ1 in the transition to perinuclear factories. Moreover, late during infection, +RNA pools largely contributed to the production of de-novo viral proteins and fully-assembled infectious viruses. Altogether the results suggest an advanced model of reovirus replication with spatiotemporal segregation of core amplification, OC complexes and fully assembled virions. Author summary: It is important to understand how viruses replicate and assemble to discover antiviral therapies and to modify viruses for applications like gene therapy or cancer therapy. Reovirus is a harmless virus being tested as a cancer therapy. Reovirus has two coats of proteins, an inner coat and an outer coat. To replicate, reovirus particles need only the inner coat, but to become infectious they require the outer coat. Strangely, inner and outer coat proteins are all made by the virus at once, so it was unknown what determines whether newly made viruses will contain just the inner coat to continue to replicate, or both coats to transmit to new hosts. Our experiments reveal that the inner coat proteins are located in a different area of an infected cell versus the outer coat proteins. The location therefore determines if the newly made viruses contain just the inner coat versus both coats. Reoviruses have evolved extravagant mechanisms to be able to efficiently take on the best composition required for replication and transmission. [ABSTRACT FROM AUTHOR]

The present study reports a novel technique to synthesise silica nanoparticles through modified sol-gel, ultrasonication, and hydrothermal routes. Physio-chemical and structural characterization was carried out using X-ray diffraction, high resolution scanning electron microscopy, energy dispersive spectroscopy, dynamic light scattering, Fourier transform infrared spectroscopy, ultraviolet-visible, and photoluminescence spectroscopy. The particle size determination revealed the spherical structure of nanoparticles with an average diameter of 85 nm and between 90-170 nm through HRSEM and DLS respectively. Stretching and vibration bands confirming the presence of SiO2 were obtained in FTIR analysis. Spectra from UV-vis and PL spectroscopy were obtained at a maximum wavelength of 233 nm and 555 nm respectively. The anti-microbial effect of SiO2 nanoparticles against E. coli and S. aureus bacteria revealed the appreciable response which renders them for many biomedical applications like drug delivery. The cytotoxicity of SiO2 nanoparticles on human lung epithelial (A549) cell line revealed their non-toxic behavior. [ABSTRACT FROM AUTHOR]

The current investigation describes the synthesis of SiTiCNO ceramics derived from the mixture of a preceramic polymer (polyvinylsilazane) and tetrabutyl orthotitanate precursors by crosslinking at 300 °C and pyrolysis in the temperature range of 900–1400 °C in flowing nitrogen atmosphere. Crosslinked precursor was studied by thermogravimetry to estimate ceramization temperature as well as ceramic yield. Further, the evolution of phase and nanostructure with temperature in the composite SiTiCNO ceramics was analyzed by the help of different characterization techniques, such as XRD, Raman, and electron microscopy. The Ti-doped SiCN ceramic system appeared as single-phase SiTiCNO amorphous up to 1100 °C. The phase separation of SiTiCNO ceramics started at 1200 °C and exhibited TiO2 nanocrystals distributed in the amorphous SiCN matrix. Ti-doping was found to accelerate the separation of the free carbon phase from the SiCN matrix, and the said carbon had better graphitic order in the Ti-doped SiCN samples as compared to the undoped SiCN of equivalent thermal history. At 1400 °C, high temperature stable phases such as TiC and TiC0.3N0.7 were formed along with predominant rutile-TiO2 phase within the Si–Ti–O–C–N composite. A uniform distribution of these nanocrystals in the SiCN matrix at 1400 °C was observed by high resolution transmission electron microscopy. The current work exhibits the formation of a unique multiphase composite with the co-existence of nanocrystalline phases uniformly distributed within a polymer derived ceramic matrix. [ABSTRACT FROM AUTHOR]

This study illustrates the synthesis of functionalized carbon quantum dots (CQDs) by the one-pot pyrolysis method. The functionalization agent used in CQD synthesis was poly l- lysine (PLL). Various physicochemical techniques were employed to confirm the successful formation of PLLCQD including High resolution transmission electron microscopy (HR-TEM), UV-Vis spectroscopy, fluorescence spectroscopy; Atomic force microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The size of PLLCQD was confirmed by HRTEM and AFM. The synthesized PLLCQD shows bright blue fluorescence and has a quantum yield of 19.35%. The highest emission band was observed at 471nm when excited to 370nm. The prepared PLLCQD exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus with inhibition zone 7-20 mm. The concentrations of 0.9 to 0.1gmL-1 were studied to determine minimum inhibitory concentration (MIC) by the agar well diffusion assay method. MIC of 0.2gml -1 concentration of PLLCQD is achieved. The anti-angiogenic activity of PLLCQD was determined using (Chick Chorioallantoic Membrane) CAM assay. CAM assay is a reliable in -vivo model to study angiogenesis also; many stimulators and inhibitors have been examined by this method. This study proves higher antibacterial efficiency of PLLCQD over non functionalized CQD. PLLCQD was successfully employed in bio-imaging of the bacterial cell through fluorescence microscopy. Further, PLLCQD displayed cytotoxic effect on endothelial cells and inhibited blood vessel formation in the CAM model. [ABSTRACT FROM AUTHOR]

Controlling the reaction kinetics during the nucleation/growth of cupric oxide (CuO) nanostructures is very critical in order to achieve a specific and well-defined morphology. For this purpose, we have slowed down the reaction speed using a mixed solvent concept and successfully obtained a chain-like morphology of CuO nanostructures using hydrothermal method. The CuO chain-like morphology was synthesized using a 1:1 (v/v) ratio of ethylene glycol and water. The morphology and crystalline features of CuO were studied by scanning electron microscopy (SEM) and powder X-ray diffraction techniques. The high resolution transmission electron microscopy revealed 5 nm crystallite size for the CuO material prepared in the mixed solvents. The obtained results have shown that the prepared CuO chains had a monocline phase, containing only Cu and O as main elements as confirmed by energy dispersive spectroscopy. This unique morphology obtained from mixed solvent process has provided a better surface for the loading of urease enzyme, thus it enabled the development of sensitive and selective urea biosensor in phosphate buffer solution of pH 7.4. The physical adsorption method was used to immobilize urease enzyme onto the nano surface of CuO. The fabricated biosensor based on urease/CuO chains has shown a dynamic linear range from 0.0005 to15 mM with a low limit of detection 0.0001 mM. Additionally, a fast response time aroudn1s, h high selectivity, stability, repeatability, storage time, and reproducibility were observed. The effect of pH and temperature on the potentiometric signal of the developed biosensor was also examined. Importantly, the practical aspects of the fabricated urea biosensor were probed and the obtained percent recovery results revealed an outstanding performance. The strategy of using mixed solvent with equal volume ratio would be useful for the preparation of other metal oxides with improved catalytic properties for a wide range of clinical, biomedical and other related applications. [ABSTRACT FROM AUTHOR]

Ion implantation induced phase transformation and the crystal structure of a series of ion implanted β-Ga2O3 samples were studied using electron diffraction, high resolution transmission electron microscopy, and scanning transmission electron microscopy. In contrast to previous reports suggesting an ion implantation induced transformation to the orthorhombic κ-phase, we show that for 28Si+, 58Ni+, and stoichiometric 69Ga+/16O+-implantations, the monoclinic β-phase transforms to the cubic γ-phase. The γ-phase was confirmed for implantations over a range of fluences from 1014 to 1016 ions/cm2, indicating that the transformation is a general phenomenon for β-Ga2O3 due to strain accumulation and/or γ-Ga2O3 being energetically preferred over highly defective β-Ga2O3. [ABSTRACT FROM AUTHOR]

Glassy carbon is frequently used in electrochemical research due to its presumed robust electrochemical performance. Although it is widely utilized as a rotating disc electrode material, the modification of glassy carbon during electro‐catalytic process is rarely emphasized or characterized. In this report, we investigated the structural modification of glassy carbon imparted by electrochemical oxidation in acidic media and compared the behavior with graphite. The functional groups generated from electrochemical oxidation in both electrodes possess similar electrochemical properties. However, above an oxidation potential of 1.8 V (vs. reversibly hydrogen electrode), glassy carbon exhibits a lower electrochemical capacitance compared to graphite. We propose that the existence of electrochemically inactive species, originating from the non‐graphitic portion of glassy carbon is attributed to such deterioration. Additionally, high resolution scanning electron microscopy (HR‐SEM) and high‐resolution transmission electron microscopy (HR‐TEM) images corroborate how electrochemical oxidation prevails for glassy carbon electrodes at oxidative potentials. The overall analysis leads us to propose a corrosion mechanism for glassy carbon in acidic solution. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Submicron‐sized wear particles are generally accepted as a potential cause of aseptic loosening when produced in sufficient volumes. With the accelerating use of increasingly wear‐resistant biomaterials, identifying such particles and evaluating their biological response is becoming more challenging. Highly sensitive wear particle isolation methods have been developed but these methods cannot isolate the complete spectrum of particle types present in individual tissue samples. Two established techniques were modified to create one novel method to isolate both high‐ and low‐density materials from periprosthetic tissue samples. Ten total hip replacement and eight total knee replacement tissue samples were processed. All particle types were characterized using high resolution scanning electron microscopy. UHMWPE and a range of high‐density materials were isolated from all tissue samples, including: polymethylmethacrylate, zirconium dioxide, titanium alloy, cobalt chromium alloy and stainless steel. This feasibility study demonstrates the coexistence of mixed particle types in periprosthetic tissues and provides researchers with high‐resolution images of clinically relevant wear particles that could be used as a reference for future in vitro biological response studies. [ABSTRACT FROM AUTHOR]

Because of its weak durability at low temperatures and low strain rates, polypropylene's use as an engineering plastic is restricted. To make polypropylene more tougher, combine it with elastomeric particles in a cost‐effective manner is an excellent option. Internal melt blending was used to manufacture polypropylene (PP) and high‐molecular‐grade ethylene‐propylene‐diene rubber (EPDM) blends with varying constitutive ratios in this work. EPDM's lower portions have especially high impact strength ratings for PP/EPDM mixtures. (i.e., 2.5, 5, and 7.5 parts per hundred EPDM rubber). The mechanically generated cavitation behavior of impact cracked specimens is obvious from SEM morphology, showing to the strong impact resistance of PP/EPDM blends. Increased EPDM content reduces the amount of scattered EPDM rubber particles by increasing the average diameter of dispersed particles, as seen by HRTEM images of the samples. The tensile and flexural properties of PP/EPDM blends were analysed. The rheological tests demonstrate that as the frequency increases, the complex viscosity drops, indicating that the melt is in a pseudoplastic condition. Due to the destruction of polymer chain mobility at greater cooling rates, DSC analysis indicates that percentage crystallinity values decrease as the cooling rate of crystallization increases, resulting in an incomplete crystallization process. The fact that PP/EPDM mixes have two glass transition temperatures indicates that they are immiscible. An investigation using the TGA found that the maximum degradation temperature (Tmax) of the PP/EPDM rubber mixtures may be sustained for long periods of time at very high operating temperatures. [ABSTRACT FROM AUTHOR]

The aim of the research was to evaluate the effects of sulfonitric and CS (CS) treatment in multilayer carbon nanotubes (MWCNT) on their electrochemical and magnetic properties. Thermogravimetric analysis (TG) showed an increase in thermal properties for CS functionalized MWCNT when compared in sulfonitric medium. High resolution transmission electron microscopy (HRTEM) images revealed a reduction in the average diameter of functionalized MWCNT in the presence of CS in addition to decreasing their interlayer spaces. As evidenced by X-ray Diffraction (XRD) patterns. In addition, X-ray photoelectron spectroscopy (XPS) spectra proved the functional groups inclusion of CS and sulfonitric solution on the (carbon nanotubes) CNT matrix. Unlike pristine MWCNT solutions which are unstable in aqueous media, functionalization with acidic solutions and contributed to its potential stabilization. The results obtained by Raman Spectroscopy prove the functionalization through the insertion of functional groups in the walls of the nanotubes. The electroanalysis showed higher capacitance values by mass and by area for samples functionalized with acids and that the addition of CS during functionalization increases the resistance to current flow, causing an insulating effect. [ABSTRACT FROM AUTHOR]

The capabilities of the liquid assisted electrical discharge technique with additional laser irradiation of colloids for the synthesis of SiC nanocrystals (NCs) have been studied. For optimization of the conditions for the binary NCs formation, the characterization of inner structure, phase composition and morphology was performed by means of high resolution transmission electron microscopy, selected area electron diffraction, X-Ray photoelectron spectroscopy, Raman and Fourier-transform infrared spectroscopy. The results of the characterization proved the formation of near-spherical SiC NCs having two-peak size distribution with average diameter of 3.7 and 11.4 nm before and 2.3 nm after additional laser treatment. The possible mechanism of nanostructured SiC formation has been discussed. The developed technique is expected to be effective for fabrication of SiC NCs as a promising material for optoelectronic devices. [ABSTRACT FROM AUTHOR]