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Building up and an investigating the efficiency of the cost-effective modified graphite for hybrid supercapacitor application is fascinating due to an extraordinary performance of graphite in battery application in day-to-day life about past decades. The metal oxides (Fe, Co, Ni) embedded in graphite was synthesized through the facile ultrasonication-assisted technique. Fe–Co–Ni deposited on graphite (Fe–Co–Ni-G) was studied structurally and morphologically by fourier transform infrared spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, and high resolution transmission electron microscopy analyses. The electrochemical studies such as cyclic voltammetry, Galvanostatic charge–discharge analysis, and electrochemical impedance spectroscopy (EIS) analysis were revealed the supercapacitor performance of Fe–Co–Ni-G composite. The superior calculated areal capacitance of Fe–Co–Ni-G was 1355 mF cm−2 at 2 mA cm−2 which was higher than single metal deposited graphite (Fe-G 490 mF cm−2 at 2 mA cm−2) composite. EIS study supported the higher diffusion process of Fe–Co–Ni-G directed to higher supercapacitor performance that is possible for day-to-day life applications. [ABSTRACT FROM AUTHOR]

In this research work, nickel dioxide (NiO2) with a fixed quantity of graphitic carbon nitride (g-C3N4) and various concentrations of yttrium (Y) (2, 4 wt%) were synthesized via the coprecipitation method. The main objective is to degrade hazardous dyes such as Rhodamine B (RhB) with synthetic material and to assess antibacterial and catalytic activity with molecular docking analysis of the synthesized Y/g-C3N4-doped NiO2 nanostructures (NSs). A series of characterizations for optical, morphological, structural, and compositional analysis of prepared NSs were monitored to better understand the obtained samples. X-ray diffraction pattern evaluated the hexagonal structure of NiO2. Fourier transform infrared spectra demonstrated the prescence of bending and stretching vibration modes. Upon the incorporation of Y and g-C3N4, no visible transmittance shift was observed. The high resolution transmission electron microscopy micrographs affirmed the formation of agglomerated NiO2 NSs with few rod-like shapes, also assured by EDS elemental configuration. The UV–vis spectra revealed a redshift upon including Y and g-C3N4 into NiO2, leading the band gap energy to decrease from 3.6 to 3.4 eV. The catalytic efficacy of prepared samples was examined against Rhodamine B (RhB) dye in the prescence of reducing agent. In an acidic medium, the highest catalytic degradation rate of 99.85% was achieved by 4% Y/g-C3N4–NiO2, ascribed to increased production of H+ ions absorbed over the NSs surface. Moreover, the antimicrobial efficacy of synthesized NSs was evaluated against Escherichia coli (E.coli) bacteria and was observed as 3.15 mm. In silico docking studies of g-C3N4/NiO2 and Y/g-C3N4–NiO2 NSs for dihydrofolatereductase (DHFR) and dihydropteroate synthase (DHPS) of E.coli postulated inhibition of the enzymes above as a possible mechanism in addition to their microbicidal activity. [ABSTRACT FROM AUTHOR]

NiMoS/TiMg and NiWS/TiMg nanocatalysts were synthesized, characterized by various techniques and tested in the hydrodesulphurization (HDS) of dibenzothiophene (DBT). TiMg mixed oxides containing 5, 10 or 15 wt% of MgO were prepared by sol–gel and then used as catalyst supports. A constant atomic ratio of Ni/(Ni + M) = 0.5 was kept for all the catalysts (M = Mo or W). The catalysts were first prepared by sequential-wet impregnation. Then, after an ex-situ sulfidation process, they were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and physisorption of N2 following the BET method. The presence of MgO in the NiMoS/TiMg and NiWS/TiMg catalysts resulted in an enhancement in the HDS activity of DBT. In addition, their HDS activities were higher than those observed in the NiMoS/Ti and NiWS/Ti catalysts. Furthermore, higher HDS activity was found for the NiMoS/TiMg compared with their NiWS/TiMg catalysts counterpart. [ABSTRACT FROM AUTHOR]

In this study, mixed phase (tetragonal and monoclinic) Zirconia nanoparticles (ZrO2 NPs) namely, ZS3, ZS7 and ZS10 were synthesized via hydrothermal method at different pH values of (3, 7, 10) respectively. A combination of Powder X-ray diffraction (PXRD), High Resolution Transmission Electron Microscopy (HRTEM), and Selected Area Electron Diffraction (SAED) characterization techniques confirmed the formation of mixed phase ZrO2 nanoparticles. The photocatalytic behavior of synthesized ZrO2 NPs was examined for the degradation of anionic Congo Red (CR) Dye under visible light irradiation. A systematic study of the efficiency of the prepared ZS3, ZS7 and ZS10 nanoparticles was compared and it was found that ZS7 outperformed the ZS3 and ZS10 materials, having removal efficiency of up to 98.9% with 0.1 g of the prepared ZS7 nanoparticles for 75 ppm of Congo Red (CR) dye. Furthermore, the surface area analysis revealed that among the prepared materials, ZS7 exhibited the highest surface area, thereby corroborating the finding of its superior catalytic efficiency. Under the optimized experimental conditions, the degradation of dye followed first-order kinetics. ZS7 showed the highest removal efficiency in just 60 min of contact time for all the CR dye concentrations ranging from 50 to 100 ppm, making it a superior catalyst for the efficient removal of the targeted Congo Red dye. [ABSTRACT FROM AUTHOR]

This paper reports synthesis by wet chemical route for neodymium doped lanthanum arsenates nanoparticles with chemical formula NdxLa1−xAsO4 (x = 0.0, 0.05, 0.10 and 0.15) and its characterization. Powder X-ray diffraction (PXRD) confirms monoclinic structure of the prepared nanomaterials. Crystallite size decreases with increasing concentration of Nd3+ ions. PXRD results are further validated by Rietveld refinement with low values of goodness factor (χ2). Morphology has been investigated by high resolution transmission electron microscopy (HRTEM) equipped with selected area electron diffraction (SAED) which shows the crystalline nature of nanomaterials. Various functional groups present have been studied by FTIR spectroscopy. The optical band gap calculated using UV–Vis diffuse reflectance spectroscopy is found to decrease with increasing dopant concentration. The emission spectrum studied by applying photoluminescence (PL) spectroscopy. At 315 nm excitation, the NdxLa1−xAsO4 exhibits a bright red emission with emission peaks in the range of 610–630 nm. Chromaticity plot shows that chromaticity coordinates are located in the red region. The dielectric analysis carried out to study variation of dielectric constant with frequency over range of 1–25 kHz and temperature range of 20–200 °C. The conductivity measurements are carried out and activation energy has been calculated. The variation of electrical modulus with frequency has also been observed. [ABSTRACT FROM AUTHOR]

The present study aimed at developing an exopolysaccharide based nanoemulsion with increased kinetic stability, solubility, and availability. The nanoformulation was fabricated employing ultrasonication, a high energy fabrication method and constituted of flaxseed oil, tween 80, ethanol, and exopolysaccharide (extracted from Ganoderma gibbosum). The resultant formulation was found to have an average droplet size of 101.5 nm, with a PDI of 0.189, and a zeta potential of -8.2 mV. The particle size was further confirmed via the high resolution transmission electron microscopy which reported the nanoemulsion droplets to be round, uniform in size, with particle size ranging between 10 to 115 nm. In terms of the thermodynamic and storage stability the formulation was found to be highly stable and resistant to creaming, phase separation, and changes in pH. Further, the results in-vivo antioxidant assay revealed an increase in the activity of serum superoxide dismutase and catalase and a decrease in the serum level of thiobarbituric acid reactive substances suggesting that the formulation is capable of ameliorating the effect of reactive oxygen species in biological system. [ABSTRACT FROM AUTHOR]

The microstructure of nanostructured bainite formed by austempering in high-carbon silicon steel is characterized by high resolution electron microscopy. The results show that the bainitic sheaves consist of nanoscale subunits. The found kinds of crystal lattice distortions of each subunit in one bainite lath show clear difference. The latest generated subunit has most distortions. As the subunit grows up, the lattice distortion gradually gets relaxed. This indicates that the subunits form with high phase transformation strain energy, which causes severe lattice distortion. The results provide new experimental evidence on subjects relevant to the understanding of the mechanism of formation of bainitic ferrite. [ABSTRACT FROM AUTHOR]

The heating characteristics of citrate-coated magnetite nanoclusters in a magnetic inductive system were analyzed with several methods, such as the numerical initial slope method, a fourth-degree polynomial, a single Box-Lucas equation, a sum of two and three Box-Lucas equations, the corrected slope method and its extension. The Box-Lucas equation was modified by considering a half-rate heating constant (λ1/2) rather than the traditional heating-rate constant (λ), which is usually presented in the literature. The nanoclusters, produced by the precipitation method were characterized with high resolution transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, thermogravimetric analysis and Fourier transform infrared spectrometry. High resolution transmission electron microscopy showed the nanoclusters of the synthesized magnetic particles. According to the X-ray diffraction data, these nanoclusters had average particle sizes ranging from 20 to 31 nm and comprised magnetite. Mössbauer spectroscopy showed the characteristic double magnetic pattern associated with the iron ions located at the A and B sites of the inverse spinel crystal structure for magnetite. Infrared peaks such as those at 1629 cm−1 and 564 cm−1 for the citrate-coated magnetite nanoclusters, suggested that citrate ions were indeed attached to the particle surfaces. Additionally, a thermogravimetric analysis showed that from 4.6 to 10.9 wt% citrate ions were attached to the particle surfaces. Both the modified Box-Lucas equation and the extension of the corrected slope method provided consistent results and greatly simplified estimation of the specific absorption rate of the magnetite nanoclusters used in the magnetic fluid hyperthermia studies. [ABSTRACT FROM AUTHOR]

Cu–Ni/SiO2 catalysts were prepared by coprecipitation method and used in the dehydrogenation reaction of secondary butyl alcohol to methyl ethyl ketone (MEK). The crystal structure, reduction characteristics, element valence state and dispersibility of the catalysts were investigated using X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H2-TPR), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectroscopy (XPS), X-ray Auger electron spectroscopy (XAES) and high resolution transmission electron microscopy (HRTEM). The role of Ni component in the dehydrogenation reaction of secondary butyl alcohol was analyzed. The results showed that the conversion of secondary butyl alcohol increased to over 99% when using the Cu–Ni/SiO2 catalyst. The addition of nickel component to Cu/SiO2 inhibited the agglomeration of copper nanoparticles. The interaction between copper and nickel was strengthened due to the formation of the Cu–Ni compound. This resulted in change to the valence state and improved the dispersion of copper species on the catalyst surface. The Cu+/(Cu+ + Cu0) ratio increased with the addition of nickel component to Cu/SiO2, which may be responsible for the enhancement of the secondary butyl alcohol conversion. However, the addition of the nickel component increased the reduction temperature of the catalysts and deteriorated their reduction characteristics, which leads to insufficient reduction, resulting in a high content of Cu+ species remaining in the catalyst. Therefore, side reactions can occur, which are detrimental to the selectivity and yield of MEK. The selectivity to MEK can reach 98% with the Cu/SiO2 catalyst, whereas that for the Cu–Ni/SiO2 catalyst was 97%. [ABSTRACT FROM AUTHOR]

Microstructural defects play a critical role in flourishing various properties of materials. Here in this article, the effect of Ag substitution on the various properties of CdS quantum dots (QDs) is studied. Ag doped CdS QDs are synthesized using chemical co-precipitation, a simple, cost-effective method suitable for mass-production. High resolution transmission electron microscopy (HRTEM) images show dopant induced change in density and types of microstructural defects. The development of multiple nanotwinning at the cost of stacking faults as well as single twin boundary via the substitution of Ag in CdS lattice is noticed. In present study, a strong quantum confinement is observed and confirmed by the crystallite sizes estimated via X-ray diffraction (XRD) and TEM studies. A systematic enhancement in the bandgap and reduction in crystallite size are observed with increasing concentration of dopant. The atomic concentration of element and chemical bonding in CdS QDs are studied using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) respectively. Unlike other elemental dopants, QDs when doped with Ag with the varying concentration exhibit a non-systematic emission behaviour with increasing concentration which is correlated to the microstructural defects and confinement strength. [ABSTRACT FROM AUTHOR]

In this report, we synthesized the neodymium-doped yttrium hydroxide nanobelts (Nd:Y(OH)3) using a facile route. The characterization methods, such as UV-Visible and photoluminescence spectroscopy, Raman, X-ray photoemission, Fourier transform infrared (FTIR) spectroscopy, and high resolution transmission electron microscopy (HRTEM), were applied to clarify the properties of the prepared colloidal sample. The structural characteristics of the prepared sample were analyzed via X-ray diffraction (XRD) and HRTEM. The average size of the hexagonal crystal is about 25 nm, which shows the compatibility of XRD and HRTEM spectroscopy results. Absorbance and emission spectra of the synthesized sample have demonstrated that the intensity of light emission by the colloidal sample is affected by the concentration of Nd3+ ions. In this research, it has been shown that the excitation of the samples with the wavelengths of 355 and 360 nm almost does not change the blue emission spectra because the wavelengths are related to the nature of the Nd+ 3, but with the excitation of 300 nm, the intensity of the emission spectra increases with the increase in the concentration up to 0.05 g (sample 2). [ABSTRACT FROM AUTHOR]

In this study, Boron Nitride Quantum Dots (BNQDs) are successfully synthesized via the hydrothermal method. Additionally, the hydrothermal method is employed to synthesize BNQDs decorated TiO2 nanograss (BNQDs/TiO2 NG) from BNQDs decorated TiO2 (BNQDs/TiO2). To validate the synthesis of different BNQDs samples, fluorescence spectroscopy (FL) is performed, revealing a strong quantum confinement effect resulting from variations in the precursor ratio. The bandgap energies of TiO2, BNQDs/TiO2, and BNQDs/TiO2 NG are determined using UV–Vis diffuse reflectance spectroscopy (UV-DRS), demonstrating a reduction in the band gap. A smaller band gap corresponds to a higher thermal conductivity, as there is a negative correlation between thermal conductivity and band gap energy. The study suggests that BNQDs/TiO2 NG exhibit higher thermal conductivity compared to TiO2 and BNQDs/TiO2. X-ray photoelectron spectroscopy (XPS) reveals the elemental composition of both BNQDs and TiO2, including Ti–O, B–N and B–O bonds. High Resolution Transmission Electron Microscopy (HR-TEM) is utilized to examine the morphological attributes of BNQDs/TiO2 NG. The crystalline structure of the synthesized composites is ascertained using X-ray diffraction (XRD). The photocatalytic degradation of methylene blue (MB) by TiO2, BNQDs/TiO2, and BNQDs/TiO2 NG under visible light is also compared. Based on the results, BNQDs/TiO2 NG is determined to be an effective material for treating wastewater containing organic dyes. [ABSTRACT FROM AUTHOR]

In the present work, zinc sulphide (ZnS) nanoparticles are synthesized via solvothermal route using different capping agents. The sphalerite phase is detected by X-ray diffraction (XRD) analysis. The morphology of the nanoparticles is confirmed by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The average particle size is found between 5 and 7 nm as calculated by HRTEM analysis. Energy dispersive X-ray spectroscopy (EDX) specified the desired elemental composition. Bandgap studies are done by UV–visible absorption and the photoluminescence spectroscopy (PL) gives the emission peaks centered at 452 nm and 460 nm. Fourier transform infra-red spectroscopy (FTIR) of ZnS nanoparticles confirmed the presence of various functional groups and showed the encapsulation of capping agents. The cylindrical non-woven network of PAN-ZnS nanofibers synthesized by electrospinning technique as confirmed by SEM and the distribution of nanoparticles in the polymer matrix is confirmed by HRTEM analysis. EDX and FTIR showed the incorporation of ZnS nanoparticles in polymer matrix. The objective of the present work is to synthesize the PAN-ZnS composite nanofibers for antibacterial applications. To the best of our knowledge this type of studies using polyacrylonitrile (PAN) as a polymer are not found in the literature showing the novelty of our work. [ABSTRACT FROM AUTHOR]

Glass matrices of Li2B4O7 doped with Dy3+, Yb3+ and Cu were synthesized using copper concentration as the control parameter by melt quenching technique. The amorphous phase of lithium borate was corroborated by X-Ray diffraction (XRD) while size distribution of Nanoparticles was obtained by transmittance electron microscopy (TEM) and crystal phase of Cu nanoparticles was obtained by high resolution transmittance electron microscopy (HRTEM). For photoluminescence, characterizations used were absorbance, photoluminescence emission (PL) and experimental decay times (τexp); from the data obtained we performed Judd–Ofelt analysis where we calculated Judd–Ofelt parameters ( Ω i ), transition probabilities (A), branching ratios (β ) and decay times (τcalc). With absorbance and PL characterizations in conjunction with CIE 1931, efficiency and shift to white light emission were evaluated. The insights gained from this study have significant implications for future research focused on enhancing the photoluminescence properties of rare earth-doped systems. A comprehensive understanding of the underlying mechanisms behind these phenomena enables us to leverage plasmon effects in similar systems, leading to diverse applications such as color tuning emission. [ABSTRACT FROM AUTHOR]

A hydrothermal method was employed for green synthesis of fluorescent carbon dots (GCDs) from Annona squamosa leaves. The synthesized GCDs were confirmed by microscopic and spectroscopic techniques such as: High Resolution Transmission Electron Microscopy (HR-TEM), Atomic Force Microscopy (AFM), UV–Vis spectrometry, Fluorescence spectrometry, X-Photoelectron Spectroscopy (XPS), X-ray Diffraction spectroscopy (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). The produced GCDs had shown multiple properties, including massive antibacterial activity at concentration 200 μg/ml. The stabilization of human red blood cells served as a method to assess the anti-inflammatory activity. We also looked at how GCDs affected the angiogenesis process. The density of blood vessels was significantly decreased after treatment with GCDs, according to the results of the Chorio-Allantoic Membrane assay (p < 0.05). As per the study prepared GCDs from fallen leaves of Annona squamosa have multifunctional applications. [ABSTRACT FROM AUTHOR]

The missing-linker defects of UiO-66 were exploited to covalently anchor Cu nanoclusters (Cu/UiO-66). The molecular interactions between the metals and oxides as copper-zirconia interfaces in Cu/UiO-66 are essential for heterogeneous catalysis, leading to remarkable synergistic impacts on activity and selectivity. Homogeneously distributed carbonaceous mixed metal oxides (CuO/ZrO2@C) nanocomposite was prepared via carbonization of the Cu/UiO-66 at 600 °C for 3 h in air. To enhance the acidity properties of the CuO/ZrO2@C nanocomposite, a small amount of sulfuric acid was added and heated at 150 °C under an N2 atmosphere (CuO/ZrO2-SO3H@C). The synthesised Cu/UiO-66 and CuO/ZrO2-SO3H@C catalysts were used as novel catalysts in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The Cu/UiO-66 and CuO/ZrO2-SO3H@C catalysts displayed complete conversion of the 4-NP solution during (4 and 2 min) stirring at room temperature, respectively. These two catalysts exhibited a high reduction rate of 8.61 × 10–3 s−1, and 18.3 × 10–3 s−1, respectively. The X-ray photoelectron spectroscopic (XPS) analysis showed the charge of copper atoms in the Cu/UiO-66 catalyst was Cu0/CuII and in the CuO/ZrO2-SO3H@C catalyst was CuI/CuII with nearly the same ratio (65/35). The particle size and the elemental composition of the CuO/ZrO2-SO3H@C catalyst were analysed by using high resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS), and elemental mapping, respectively. The key point beyond the high catalytic activity and selectivity of the CuO/ZrO2-SO3H@C catalyst is both the carbon–metal oxides heterojunction structure that leads to good dispersion of the CuO and ZrO2 over the carbon sheets, and the high acidity properties that come from the combination between the Brønsted acid sites from sulfuric acid and Lewis acid sites from the UiO-66. The catalysts exhibited good recyclability efficiency without significant loss in activity, indicating their good potential for industrial applications. [ABSTRACT FROM AUTHOR]

Bismuth ferrite with manganese doping (BiFe0.95Mn0.05O3 or BFMO) and bismuth ferrite with cobalt and manganese doping (Bi0.95Co0.05Fe0.95Mn0.05O3 or BCoFMO) were both synthesized as nanocrystalline powders by the sol–gel autocombustion technique. X-ray diffraction examination of the powders indicates a rhombohedral distortion in the perovskite phase in both samples. The calcined powders were examined for their microstructure and elemental composition with high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDAX), respectively. Scanning electron microscopy (SEM) was used to examine the microstructures of sintered BMFO and BCoFMO specimens at room temperature. Dielectric characteristics were studied at various frequencies and temperatures and found to follow space charge polarization. At ambient temperature, a vibrating sample magnetometer was used to analyse the materials' magnetic behaviour (M–H loops). Saturation magnetization is significantly increased with increased coercivity in the BCoFMO sample compared to the other sample. Improved structural, dielectric, and magnetic values in these doped systems, however, suggest they'd be an excellent fit for spintronic, multifunctional memories, sensors, and actuators. [ABSTRACT FROM AUTHOR]

The structural properties of (x)CuO/(1-x)CdFe2O4 nanocomposites for x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 1.0 were studied. The X-ray diffraction (XRD) patterns confirmed the existence of both phases with a secondary phase of α-Fe2O3. The Fourier-transform infrared spectroscopy (FTIR) characterization showed the vibrational bands of the synthesized samples. The high resolution transmission electron microscopy (HRTEM) micrographs revealed the presence of CuO, CdFe2O4, and α-Fe2O3 phases and showed the polycrystalline nature of the prepared nanocomposites. The scanning electron microscope (SEM) study exhibited the morphology of the prepared nanostructures and indicated the agglomeration between them. The energy-dispersive X-ray spectroscopy (EDX) results revealed the presence of all chemical elements within the synthesized nanocomposites. Emission peaks of the samples were analyzed via Photoluminescence (PL) deconvolutions which approved the interface defects. The Mössbauer study showed the presence of hematite impurity and the results were coherent with XRD findings. The obtained M-H loops from the vibrating-sample magnetometer (VSM) analysis depicted a paramagnetic nature of CuO and showed the ferromagnetic behavior of the nanocomposites. [ABSTRACT FROM AUTHOR]

In this research work, carbon dots (CDs) were synthesized from the renewable leaves of an indigenous medicinal plant by the one-pot sand bath method, Azadirachta indica. The synthesized CDs were characterized for its optical properties using UV–Vis, Fluorescence and Fourier transform infrared (FT-IR) spectrophotometry and for structural properties using dynamic light scattering (DLS), X-ray Diffraction (XRD) and high resolution Transmission electron microscopy (HR-TEM). The synthesized CDs exhibited concentration dependent biocompatibility when tested in mouse fibroblast L929 cell line. The EC50 values of biomedical studies, free radical scavenging activity (13.87 μgmL−1), and total antioxidant capacity (38 μgmL−1) proved CDs were exceptionally good. These CDs showed an appreciable zone of inhibition when examined on four bacterial (two gram-positive and gram-negative) and two fungal strains at minimum concentrations. Cellular internalisation studies performed on human breast cancer cells (MCF 7- bioimaging) revealed the applicability of CDs in bioimaging, wherein the inherent fluorescence of CDs were utilised. Thus, the CDs developed are potential as bioimaging, antioxidants and antimicrobial agents. [ABSTRACT FROM AUTHOR]

The objective of the study was carboxyl functionalization of Fe3O4 coated multiwalled carbon nanotubes (MWCNTs), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) / N-hydroxysuccinimide (NHS) mediated immobilization of Candida rugosa lipase on MWCNTs through rigid base of dopamine, flexible spacer ethyl methacrylate with adipic acid for improved enzyme characteristics including enhanced dispersion and separation; and use in production of flavour esters ethyl butyrate and butyl butyrate. The immobilized enzyme nanoparticles were characterised by using high resolution transmission electron microscopy (HRTEM), Fourier transmission infrared spectroscopy (FTIR), x-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), zeta potential analysis. Maximum protein loading of 133.83 mg g−1 support and immobilized enzyme activity 4,889.2 U g−1 support was obtained at the optimal time, pH, temperature, protein to support ratio. Immobilized enzyme was tested for pH, thermal, and storage stability. The esterification yields of ethyl butyrate 89.69% and butyl butyrate 91.07% were obtained under optimal conditions. The immobilized enzyme was separated from reaction mixture using the superparamagnetic property and reused for 11 cycles of esterification. Study showed the immobilized enzyme could be used for production of various fruit flavour esters. [ABSTRACT FROM AUTHOR]

The present work is performed on Pb2+ detection via electrochemical sensor. The novel aptasensor was developed by modification of glassy carbon electrode (GCE) with reduced graphene oxide (rGO) and gold nanoparticles (AuNPs) modified with ssDNA. The synthesized nanoparticles were characterized by HRTEM (high resolution transmission electron microscopy), SAED (selected area electron diffraction), UV–Vis spectrophotometer, FTIR, and XPS. The rGO was prepared by electrochemical reduction and thickness of rGO sheet was 0.5 to 1 nm. The average AuNPs size was 20–25 nm. The Pb2+ ion binds with specific ssDNA, and it will induce conformational changes of the aptamer and corresponding modulation of electrochemical signals. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for Pb2+ detection and optimization of sensor. The proposed aptasensor exhibits high sensitivity toward detection of Pb2+ ions with a detection limit of 1.52 nM and linear range of 5–50 nM at a signal-to-noise ratio of 3. Moreover, this aptasensor produces satisfactory results in environmental water samples analysis. The results of the newly developed aptasensor show better sensitivity and selectivity than the previously described electrochemical sensor. [ABSTRACT FROM AUTHOR]

Poly(vinyl chloride) (PVC) is one of the most used polymers, but the mechanical and esthetic properties can deteriorate for use outdoors because of ultraviolet (UV) light or heat. The addition of stabilizers is indispensable method for improving the stability of PVC. In this work, a facile synthetic method of CeO2 quantum dots (QDs) was used, for achieving the best dispersion and improvement of anti-UV properties, the surface of CeO2 QDs was modified by ethyl 3,4-dihydroxybenzoate (EDHB), which was dispersed within the PVC matrix using the casting method to investigate the anti-UV and thermal properties. X-ray powder diffraction spectra (XRD), infrared spectroscopy (FT-IR), high resolution transmission electron microscopy (HRTEM), UV spectrophotometry and thermogravimetric analysis (TGA) were applied to characterize the structures, morphologies, and properties. The results highlighted that EDHB/CeO2 can help reduce damages of PVC upon exposure to ultraviolet (UV) light and heat. [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]

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]

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 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]

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]

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]

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]

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]

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]

An effort has been made to develop and synthesize novel CoCr2O4@GeO2@ZnO core–shell nanostructure gas sensor via sol–gel method. The products obtained were analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDAX), and Brunaure–Emmet–Teller (BET) analysis. In the present study gas sensing properties of CoCr2O4, CoCr2O4@GeO2, and CoCr2O4@GeO2@ZnO were studied. The thick films of cobalt chromite and core–shell CoCr2O4@GeO2, and CoCr2O4@GeO2@ZnO were prepared by screen printing technique. The sensing efficiency of these films was checked for various gases including CO, CO2, Cl2, H2, NH3, and H2S. Among these metal oxide-based sensing materials, CoCr2O4@GeO2@ZnO shows highest response at 200 °C for H2S is 627.01, as compared CoCr2O4@GeO2 is 524.01. The pure chromite (CoCr2O4) shows NH3 gas response is 513.21 at 250 °C. The gas response, selectivity, thermal stability and recovery time of sensor is also studied. The humidity dependence of the sensor response for CoCr2O4@GeO2@ZnO was investigated within the test chamber at 100 °C. The statistical analysis data for gas detection is also predicted. [ABSTRACT FROM AUTHOR]

Flexural behavior of red deer's (Cervus Elaphus) antler is managed by not only orientation of osteons but also age, number density of fully fledged Cross-Linking Fibers (CLFs) and mineralization. Although crack propagation is affected by all these factors, a possible role of CLFs during the deformation remains rather disguised. The aim of this study was to enlighten the effect of dimensions, micro skeleton and mineral content of CLFs on plastic deformation. Therefore, mechanical properties, microarchitecture and mineralization of fracture sites of deer antlers were investigated using three-point bending tests in 32 specimens followed by high resolution scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The bending tests show that maximum bending strength is in the range of 150–177 MPa, and elastic modulus approximates to 5–6 GPa. Furthermore, fracture toughness of the test specimens examined for all branching groups of antlers was 8–9 MPa · m 1 / 2 . Age and the number of branching albeit are main reasons for differentiating microarchitecture and varying mechanical properties. SEM analyses show that a hierarchical architecture from bottom to up exists, in which some feathers and nano-sized fibrils are attached to larger fibrils that brings CLFs altogether. Antlers of adolescent deers are supposed to have shorter and thinner cross-linking fibers than elder ones. Some feathered micro-fibrils were identified across the CLFs connecting osteons. The thickness (270.0–320.0 nm) and length (700 nm) of feathers were strictly proportional to the microfibrils' size (10.0 µm in length and 1.0 µm in thickness). Furthermore, weight percentages of minerals varies along the CLFs that taking root on osteons by a bundle of many smaller fibrils whereas Pb, Cd and Hg have the highest values at the tip of broken CLFs. Such high values of these brittle elements lead to cracked ligament bridging as well. [ABSTRACT FROM AUTHOR]

Endovascular treatment with stent retriever thrombectomy is a major advancement in the standard of care in acute ischemic stroke (AIS). The modalities through which thrombi embed along stent retriever following mechanical thrombectomy (MTB) have not yet been elucidated. Using scanning electron microscopy (SEM), we analyzed the appearance of thrombi retrieved by MTB from AIS patients, when embedded into the stent retriever. We observed that the organization and structural compactness vary for compositionally different thrombi. The modalities of attachment onto the stent vary according to thrombus composition and organization. [ABSTRACT FROM AUTHOR]

Owing to their autocatalytic properties, gold nanoparticles (AuNPs) are used in biomedical applications. While their usage in neurodegenerative disease control, diabetes, etc. has been documented, their function is mostly untapped in cardiovascular disease treatment. Hence, in this work is the leading to combine, classify and test cardiomyoblast hypertrophy efficiency of AuNPs. In the case of AuNPs, the Imperata cylindrica extracts (IPC) and gold solution (HAuCl4) were fabricated with 1:5 volume ratios and were distinguished by specific processes, such as ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The radical scavenging of superoxide and hydroxylic AuNPs has been shown to be stronger relative to bulk gold and extracts. In cell line tests, rat cardiomyoblasts H9c2 and 3T3 fluorescence were used in this work. The generation of intracellular superoxide anion was less due to the incubation of greater AuNPs levels. In addition, preliminary findings gave an insight into the role of AuNPs in attenuating cardiomyoblastic induced isoproterenol hypertrophy. [ABSTRACT FROM AUTHOR]

Conversion of methanol to dimethyl ether (MTD) has known to be one of the main routes for the production of a clean bio-fuel, i.e., dimethyl ether (DME). However, efficient, selective, and stable catalyst is highly required for production of DME especially at relatively low temperature. Herein, aluminum phosphate nanocatalysts were fabricated by a co-precipitation method in the presence of triethylamine (TEA) as a surfactant. Thermal, structural, spectroscopic, morphological and texture properties of the catalysts were characterized by thermal analyses (TG–DTA), X-Ray diffraction (XRD), Fourier transform infrared (FTIR), high resolution transmission electron microscopy (HR-TEM) and N2-sorption analyses. In addition, the acidity of these catalysts was evaluated by isopropyl alcohol dehydration and chemisorption of basic probes. Results of acidity and pyridine-TPD indicated that these catalysts possessed Brϕnsted acidic sites of weak and intermediate strengths. The results of catalytic activity demonstrated that aluminum phosphate nanocatalyst (AP1T1) calcined at 400 °C exhibited the best catalytic performance for methanol dehydration into DME with a conversion of 100% and a 100% selectivity at 250 °C. In addition, this catalyst (AP1T1) exhibits a unique behavior where its catalytic performance only decreases by 10% upon increasing the % of methanol in the reacting feed to 35%. Moreover, it possessed excellent long-term stability with almost the same efficiency after a period of 120 h. The observable catalytic activity of these catalysts was well linked to the catalyst acidity and the activation energy. [ABSTRACT FROM AUTHOR]

In this paper, Reduced Graphene Oxide (rGO)/ZnFe2O4 (rZnF) nanocomposite is synthesized by a simple hydrothermal method and employed as a counter electrode (CE) material for tri-iodide redox reactions in Dye sensitized solar cells (DSSC) to replace the traditional high cost platinum (Pt) CE. X-ray diffraction analysis and High resolution Transmission electron microscopy, clearly indicated the formation of rZnF nanocomposite and also amorphous rGO sheets were smoothly distributed on the surface of ZnFe2O4 (ZnF) nanostructure. The rZnF-50 CE shows excellent electro catalytic activity toward I3− reduction, which has simultaneously been confirmed by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization measurements. A DSSC developed by rZnF-50 CE (η = 8.71%) obtained quite higher than the Pt (η = 8.53%) based CE under the same condition. The superior performances of rZnF-50 CE due to addition of graphene in to Spinel (ZnF) nanostructure results in creation of highly active electrochemical sites, fast electron transport linkage between CE and electrolyte. Thus it's a promising low cost CE material for DSSCs. [ABSTRACT FROM AUTHOR]

The current work focusses on the silver nanoparticles (Ag-NPs) that are conveniently green synthesized by Mangifera indica gum powder extract. The absorbance is measured by UV–Vis spectrophotometer at a wavelength of 455 nm that represents the Surface Plasmon Resonance of Ag-NPs. Fourier Transform-Infra Red (FT-IR) spectroscopy confirms the functional groups and reaction mechanisms involved in the green synthesis of Ag-NPs. The elemental analysis of Ag-NPs is carried out by Energy dispersive X-ray (EDAX) spectrum and its surface morphology was studied by High resolution transmission electron microscopy (HR-TEM). The average size of Ag-NPs is found to be around 19 nm in diameter. The crystalline nature of the Ag-NPs is investigated by X-ray diffraction (XRD) and Selected area diffraction (SAED). The Ag-NPs shows better antioxidant activity against free radicals such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide anion. Ag-NPs effect on reduction mild steel corrosion is examined using non electrochemical methods. It is proved from experimental tests that the inhibition efficiency increases with increased concentrations of Ag-NPs. The photocatalytic activity of the prepared Ag-NPs under visible light irradiation is assessed by the degradation of methylene blue (MB) dye. [ABSTRACT FROM AUTHOR]

In this study, the influence of incorporation of gadolinium ions in CdTe quantum dots lattice on the biodistribution of [68Ga] Ga@Gd-CdTe QDs nanoparticles was investigated. [68Ga] Ga@Gd-CdTe QDs nanoparticles were prepared using high purity [68Ga] GaCl3 and thioglycolic acid (TGA) capped Gd-CdTe QDs. TGA capped Gd-CdTe QDs were characterized with high resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), infrared spectroscopy (FTIR), UV–Vis spectroscopy, photoluminescence spectroscopy and vibrating sample magnetometry (VSM). The radiochemical purity and stability of the [68Ga] Ga@Gd-CdTe QDs were performed using conventional instant thin layer chromatography. In-vivo biodistribution studies in rats bearing fibrosarcoma tumors were performed by intravenously injection of [68Ga] Ga@Gd-CdTe QDs nanocomposite followed by positron emission tomography (PET) imaging. High (8.8%) and rapid (after 24 min) tumor uptake of [68Ga] Ga@Gd-CdTe QDs were observed. [ABSTRACT FROM AUTHOR]

Some of ultrafine-grained (UFG) metals including UFG twinning induced plasticity (TWIP) steels have been found to overcome the paradox of strength and ductility in metals benefiting from their unique deformation modes. Here, this study provides insights into the atomistic process of deformation twin nucleation at Σ3{111} twin boundaries, the dominant type of grain boundary in this UFG high manganese TWIP steel. In response to the applied tensile stresses, grain boundary sliding takes place which changes the structure of coherent Σ3{111} twin boundary from atomistically smooth to partly defective. High resolution transmission electron microscopy demonstrates that the formation of disconnection on Σ3{111} twin boundaries is associated with the motion of Shockley partial dislocations on the boundaries. The twin boundary disconnections act as preferential nucleation sites for deformation twin that is a characteristic difference from the coarse-grained counterpart, and is likely correlated with the lethargy of grain interior dislocation activities, frequently seen in UFG metals. The deformation twin nucleation behavior will be discussed based on in-situ TEM deformation experiments and nanoscale strain distribution analyses results. [ABSTRACT FROM AUTHOR]

Poly(methacrylic acid)/organoclay nanocomposites were prepared and characterized. Natural clay was chemically modified to form organoclay using the organo-modifier tributylhexadecylphosphonium bromide. The obtained organoclay was characterized by Fourier transform infrared (FTIR) spectroscopy, wide angle X-ray diffraction (WAXRD), and high resolution transmission electron microscopy (HRTEM). The results display that the organomodifier was intercalated between the clay layers. Methacrylic acid was then polymerized through in-situ solution polymerization technique in presence of different proportions of organoclay; 1, 3, 5, and 7wt.% and triethyleneglycol dimethacrylate as a crosslinker. Crosslinked poly(methacrylic acid)/organoclay nanocomposites were characterized by WAXRD, HRTEM, thermogravimetric analysis (TGA). The results showed that the structure of the prepared nanocomposites is intercalated structure. The prepared nanocomposites were evaluated for their methylene blue dye removal from aqueous systems. The results showed that the nanocomposite containing 3 wt.% organoclay has high dye adsorption capacity reached to 160 mg/g. The adsorption isotherms and kinetic models were performed and the results indicated that the adsorption was fit with Langmuir isotherm and belongs to second order kinetics. Regeneration of the nanocomposite was performed and involved in another adsorption cycles which displayed stable efficiency after 5 cycles. [ABSTRACT FROM AUTHOR]

The study of nanocomposites formed by doping of graphene oxide with a metal and polymer is presented in this paper. The graphene oxide contains oxygenated functional groups, like epoxy, hydroxyl and carboxyl, as shown by Fourier transform infrared spectroscopy (FTIR) studies. The existence of these functional groups on the surface of graphene oxide disperses the polymer chain and leads to a good interaction with the metal. The characterization of the prepared nanocomposite was done by X-ray diffraction, energy dispersive X-ray analysis, FTIR, Raman spectroscopy, scanning electron microscopy and high resolution transmission electron microscopy. The results showed that the obtained nanocomposite comprises nano-shaped thin stacked flakes with a well-defined multilayered edge structure. It was also seen that the metal particles were uniformly dispersed on the graphene surface with an average particle size of 1–25 nm. The synthesized nanocomposites can be used for adsorption and degradation of dyes. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been widely used in antibacterial fields due to their excellent antibacterial effects. Here, by using a dietary flavonoid found in edible plants, kaempferol (Kae), as reducing and capping agent, a facile and eco-friendly method was developed to synthesize the uniform and long-term stable silver nanoparticle/kaempferol composites (Kae-AgNPs). Kae-AgNPs were characterized by ultraviolet visible (UV–Vis) spectroscopy, Fourier transform infrared spectrum (FT-IR) spectroscopy, dynamic light scattering (DLS), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Kae-AgNPs with a size about 10 nm were synthesized by 0.1 mmol/L Kae. Lower concentration of Kae was shown with smaller Kae-AgNPs due to a few of Kae molecules expected to reduce a small number of Ag+ ions to metallic silver. Aqueous Kae-AgNPs were very stable and could be stably dispersed in water for about two months as evidenced by DLS detection, and the stability was further confirmed by XPS. Antibacterial analysis against Escherichia coli (ATCC 8099) and Staphylococcus aureus (ATCC 6538) strains showed that Kae-AgNPs displayed superior antibacterial effects than AgNPs or Kae alone, and interestingly, much better than that of the analogous nano-silver composites in the previous studies. Moreover, Kae-AgNPs with a low concentration of 2 μg/mL demonstrated highly effective antibacterial activity against E. coli (1 × 106 CFU/mL). The antibacterial mechanisms of Kae-AgNPs included the destruction of the membrane structure of bacteria, leakage of the cell contents, inducing the production of reactive oxygen species (ROS), and eventually resulting in bacteria death. The results suggest that Kae-AgNPs have high efficiency against bacteria, and have the potential to be further developed as promising antibacterial nanocomposites. [ABSTRACT FROM AUTHOR]

Citrate sol–gel method has been employed for synthesis of Zn1˗x˗yMnxCryO nanomaterials. Binary Zn0.9Mn0.1O and Zn0.9Cr0.1O nanomaterials were prepared and their optical and magnetic properties were investigated as reference compositions for the individual behavior of both of Mn- and Cr doping, respectively. The synthesized nanoparticles were analyzed using X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), ultraviolet–visible (UV–Vis) spectroscopy and vibrating sample magnetometer. For low Mn–Cr-codoping contents, i.e., 2 and 4%, XRD revealed formation of single-phase ZnO nanoparticles in the wurtzite type hexagonal lattice, whereas 10% doping concentration, either Mn- or Cr-single doping or codoping, resulted in formation of wurtzite ZnO as a major phase with ZnMnO3 or/and ZnCr2O4 secondary phases. From XRD and HRTEM, the produced nanomaterials have average crystallite sizes ranged from 15 to 35 nm. Applying Kubelka–Munk function, optical band gap energy (Eopt) was determined. Eopt of single Mn- and Cr-doped ZnO increased than that of bulk ZnO mainly due to Burstein–Moss effect, whereas it decreased in the codoped Zn1−x−yMnxCryO because of the negative and positive corrections in the conduction and valence band, respectively, brought about by alteration of the sp–d exchange interactions between the band electrons and the localized d-electrons of the Mn2+ and Cr3+ ions. Magnetization measurements indicated that Cr induced the paramagnetism, while Mn induced the RT ferromagnetism in the synthesized Zn1−x−yMnxCryO nanoparticles. The ferromagnetic Zn1−x−yMnxCryO compositions could be potential candidates for Mn–Cr-codoped ZnO-based DMS nanoparticles. [ABSTRACT FROM AUTHOR]

The present study was reported with synthesize of copper oxide nanoparticles by ethno botanical species. Bio convivial and compatible approaches were made to utilize the renewable source of leaves extract of Achyranthes aspera Linn as efficient capping and stabilizing agent as well. Also, natural A. aspera was functioned as reductant in the formation of CuO NPs. The phytosynthesized CuO nanoparticles were extensively characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, Scanning electron microscopy, Energy dispersive X-ray diffraction, High resolution tunnelling electron microscopy and also comprehensively examined their biological applications like antibacterial and antifungal susceptibility against E. lenta, E. aerogenes and C. albicans strains. An XRD result of prepared CuO nanoparticles reveals the monoclinic crystalline structure and average crystallite size of 11–16 nm. The morphology variations for different concentrations of precursor material were noticed by SEM image. Furthermore, the crystalline planes found in SAED pattern of synthesized CuO NPs were coincide to the analysed XRD spectra. In the present study, a novel green approach was used to synthesize of CuO NPs for the antibacterial activity of poorly characterized and emerging pathogens of E. lenta and E. aerogenes. Further, the physicochemical, morphological and biological properties of CuO NPs are discussed. [ABSTRACT FROM AUTHOR]

In this paper, we report a clean and green synthetic route of copper nanoparticles from copper salt using extract of basil (Ocimum tenuiflorum) flowers along with the study of their ability for selective amino acid detection. Using ultraviolet visible spectroscopy, the formation of biogenic copper nanoparticles in the medium was monitored at periodic intervals. Standard characterization techniques like high resolution transmission electron microscopy and X-ray diffraction were performed to reveal the microstructure and different phases of these extract-derived nanoparticles. Fourier transform infra-red curve detected the functional organic moieties involved in the capping and surface stabilization of the copper nanoparticles. Most significantly, we demonstrated the selective amino acid sensing ability of these bioengineered copper nanoparticles and discussed the possible mechanism behind this instant visual detection. [ABSTRACT FROM AUTHOR]

Immunofluorescence microscopy is routinely used in the diagnosis of and research on renal impairments. However, this highly specific technique is restricted in its maximum resolution to about 250 nm in the lateral and 700 nm in the axial directions and thus not sufficient to investigate the fine subcellular structure of the kidney's glomerular filtration barrier. In contrast, electron microscopy offers high resolution, but this comes at the cost of poor preservation of immunogenic epitopes and antibody penetration alongside a low throughput. Many of these drawbacks were overcome with the advent of super-resolution microscopy methods. So far, four different super-resolution approaches have been used to study the kidney: single-molecule localization microscopy (SMLM), stimulated emission depletion (STED) microscopy, structured illumination microscopy (SIM), and expansion microscopy (ExM), however, using different preservation methods and widely varying labelling strategies. In this work, all four methods were applied and critically compared on kidney slices obtained from samples treated with the most commonly used preservation technique: fixation by formalin and embedding in paraffin (FFPE). Strengths and weaknesses, as well as the practicalities of each method, are discussed to enable users of super-resolution microscopy in renal research make an informed decision on the best choice of technique. The methods discussed enable the efficient investigation of biopsies stored in kidney banks around the world. [ABSTRACT FROM AUTHOR]

In this report, the Polypyrrole, PPy/Sn and PPy/SnO2 nanocomposites have been prepared through a facile chemical oxidation polymerization (COP) techniques. The resulting nanocomposites were characterized by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and UV–Visible spectroscopy (UV–Vis). FTIR analysis confirms the presence of nano tin and SnO2 particles in the molecular structure. XRD patterns revealed that the sample is crystallite nature with tetragonal structure. The average crystallite size for the PPy/SnO2 and PPy/Sn nanocomposites are 27 and 56 nm. In addition to this, the surface morphologies and elemental compositions were investigated by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and Energy-dispersive X-ray spectroscopy (EDX). We obtained the aggregate, hollow nanosphere for PPy/Sn nanocomposites. The results indicate that the hollow sphere of the nanocomposites effectively enhances the electrical conductivity. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiO) nanosheets (NSs) deposited on different amounts (0.025, 0.05, 0.1, and 0.2 wt%) of reduced graphene oxide (rGO) are synthesized through hydrothermal method. The NiO NSs on rGO (rGO-NiO) are characterized by using X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) analyses, and electrochemical analysis. Electrocatalytic activity of rGO-NiO nanocomposite modified glassy carbon (GC/rGO-NiO) electrode is examined towards electrocatalytic oxidation of urea in 0.1 M NaOH using cyclic voltammetry and amperometry techniques. The GC/rGO0.1-NiO nanocomposite modified electrode shows enhanced electrocatalytic oxidation of urea than that of other modified electrodes due to the incorporation of NiO NSs on an optimum amount of rGO. The GC/rGO0.1-NiO modified electrode is used for designing electrochemical sensor for urea, and the detection limit is estimated as 0.47 μM using the amperometry technique. The sensitivity of GC/rGO0.1-NiO modified electrode is found to be 2450 μA mM−1 cm−2. In addition to good electroanalytical performance, the present urea sensor displayed good stability and acceptable anti-interference ability in the presence of 20-fold excess concentration of relevant interferents. The GC/rGO0.1-NiO nanocomposite modified electrode is successfully used for the determination of urea in water sample. [ABSTRACT FROM AUTHOR]

Green synthesis of cadmium oxide nanoparticles (CdO NPs) using leaves extract of Phoenix roebelenii as a novel natural reducing/stabilizing agent was reported for the first time. The structure, morphology and optical properties of the synthesized CdO NPs were studied by various physical techniques. X-rays diffraction (XRD) analysis provided evidence of single face centered cubic Monteponite phase of the CdO NPs. Selected area electron diffraction analysis (SAED) confirmed the crystalline structure of the synthesized sample. High resolution transmission electron microscopy (HRTEM) results showed spherical nanoparticles with an average diameter of 34.9 ± 0.4 nm. The isothermal behavior of CdO NPs was investigated by differential thermal analysis/thermogravimetric analysis (DTA/TGA) and the results confirmed the stability of the CdO NPs after calcination at 500 °C. The diffuse reflectance spectroscopy (DRS) indicated the presence of direct and indirect band gap with energy 2.39 and 1.91 eV respectively. Fourier Transform Infrared analysis (FTIR) showed the functional groups of bioactive compounds of Phoenix roebelenii leaves extract. Possible mechanism of interaction between these bioactive compounds and Cd precursor was proposed based on the FTIR results. [ABSTRACT FROM AUTHOR]