scholarly journals Studies on the phase transitions and properties of tungsten (VI) oxide nanoparticles by X-Ray diffraction (XRD) and thermal analysis

2017 ◽  
Vol 26 (1) ◽  
pp. 13-20 ◽  
Author(s):  
S.F. Abdullah ◽  
S. Radiman ◽  
M.A. Abdul Hamid ◽  
N.B, Ibrahim
Keyword(s):  
Thermal Analysis ◽  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Average Diameter ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Scherrer Formula

Tungsten (VI) oxide, WO3 nanoparticles were synthesized by colloidal gas aphrons (CGAs) technique.  The resultant WO3 nanoparticles were characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of the WO3 nanoparticles. As a comparison, transmission electron microscope (TEM) was used to investigate the size of the WO3 nanoparticles.  The result from XRD and DTA show that the formation of  polymorphs WO3 nanoparticles have the following sequence: orthorhombic (bWO3) ® monoclinic (g-WO3) ® triclinic (d-WO3) ® monoclinic (e-WO3) with respect to the calcination temperature of 400, 500, 600 and 700°C.  No diffraction  peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was  obtained at this temperature whereas the crystallinity had been obtained by the other samples of the WO3 nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C.  It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ± 5), (50 ± 5), (150 ± 10) and (200 ± 10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using  Debye-Scherrer formula.  The TG curve revealed that the WO3 nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 – 1.4) % from 30 until  600°C for the WO3 nanoparticles calcined at 400°C.  Finally, the composition and the purity of the WO3 nanoparticles have been examined by X-Ray photoelectron spectroscopy (XPS).  The results indicate no significant changes to the composition and the purity of the WO3 nanoparticles produced due to the  temperature variations.                                             

scholarly journals S tudies on the phase transitions and properties of tungsten (VI) oxide nanoparticles by X - Ray diffraction (XRD) and thermal analysis

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
S.F. Abdullah ◽  
S. Radiman ◽  
M.A. Abdul Hamid ◽  
N.B. Ibrahim
Keyword(s):  
Thermal Analysis ◽  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Average Diameter ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Scherrer Formula

Tungsten (VI) oxide, WO3nanoparticles were synthesized by colloidal gas aphrons(CGAs) technique.The resultant WO3nanoparticleswere characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of theWO3nanoparticles. As a comparison, transmission electron microscope (TEM) was used to investigate the size of the WO3nanoparticles. The result from XRD and DTA show that the formation of polymorphsWO3nanoparticles have the following sequence: orthorhombic (b-WO3)®monoclinic (g-WO3) ®triclinic (d-WO3) ®monoclinic (e-WO3) with respect to the calcination temperature of 400, 500, 600 and 700°C. No diffraction peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was obtained at this temperature whereas the crystallinity had been obtained by the other samples of theWO3nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C. It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ±5), (50 ±5), (150 ±10) and (200 ±10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using Debye-Scherrer formula. The TG curve revealed that the WO3nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 –1.4) % from 30 until 600°C for the WO3nanoparticles calcined at 400°C. Finally, the composition and the purity of the WO3nanoparticleshave been examined by X-Ray photoelectron spectroscopy (XPS). Theresults indicate no significant changes to the composition and the purity of the WO3nanoparticle produced due to the temperature variations 

Green preparation of carbon dots for Hg2+ detection and cell imaging

2020 ◽  
Vol 10 (11) ◽  
pp. 1777-1787
Author(s):  
Yadian Xie ◽  
Shanshan Wang ◽  
Ning Fu ◽  
Yan Yang ◽  
Xingliang Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
High Sensitivity ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon And Nitrogen ◽  
Transmission Electron ◽  
Sensitivity And Selectivity ◽  
Ft Ir

Carbon dots (CDs) also nitrogen-doped CDs (N-CDs) were produced by green hydrothermal synthesis using Pea and ethanediamine as the carbon and nitrogen source, separately. Transmission electron microscopy (TEM) images displayed that the prepared CDs and N-CDs were well dispersed, had a spherical morphology. X-ray diffraction (XRD) figures of CDs and N-CDs presented a graphitic amorphous structure. Fourier transform infrared spectroscopy (FT-IR) verified that CDs and N-CDs carried many different hydrophilic groups (for example hydroxyl, carboxyl/carbonyl, amide, amino groups) on the surface, X-ray photoelectron spectroscopy (XPS) together verified this result. However, the optical properties and fluorescence quantum yield for N-CDs were obviously superior to those of CDs. Furthermore, the prepared N-CDs displayed outstanding advantages including low toxicity, satisfactory biocompatibility, and excellent chemical stability. More prominently, the prepared N-CDs could detect Hg2+ ions with high sensitivity and selectivity in both water samples and HeLa cells.

scholarly journals Synthesis and Properties of Nanosized Stoichiometric Cobalt Ferrite Spinel

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1241 ◽  
Author(s):  
Vilém Bartůněk ◽  
David Sedmidubský ◽  
Štěpán Huber ◽  
Marie Švecová ◽  
Pavel Ulbrich ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Physical Property Measurement System ◽  
Physical Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Property Measurement ◽  
Scherrer Formula ◽  
Ferrite Spinel

Nanoparticles with controllable sizes of ferrite spinel CoFe2O4 were formed by thermal treatment of cobalt-iron glycerolate. Thermal behavior during the heating was studied by differential thermal analysis combined with thermogravimetry. The precursor, as well as the prepared nanoparticles, were analyzed by a broad spectrum of analytic techniques (X-Ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), Energy dispersive spectroscopy (EDS), Atomic absorption spectroscopy (AAS), Scanning electron microscopy (SEM), and Raman spectroscopy). The particle size of nanoparticles was obtained from Transmission electron microscopy and also calculated using Scherrer formula. A vibrating sample magnetometer (VSM) in a Physical Property Measurement System was used to analyze the magnetic properties of nanoparticles.

scholarly journals Physical Characteristics of Titania Nanofibers Synthesized by Sol-Gel and Electrospinning Techniques

2010 ◽  
Vol 5 (1) ◽  
pp. 155892501000500 ◽  
Author(s):  
Soo-Jin Park ◽  
Yong C. Kang ◽  
Ju Y. Park ◽  
Ed A. Evans ◽  
Rex D. Ramsier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ceramic Nanofibers ◽  
Titania Nanofibers

Titania nanofibers were successfully synthesized by sol-gel coating of electrospun polymer nanofibers followed by calcining to form either the pure anatase or rutile phases. Characterization of these materials was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis spectroscopy techniques. The average diameter of these ceramic nanofibers was observed to be around 200 nm for both the rutile and anatase forms. The valence band structure and optical absorption thresholds differ, however, indicating that nanofibrous mats of titania can be selectively developed for different applications in catalysis and photochemistry.

scholarly journals Synthesis of Thermally Spherical CuO Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Nittaya Tamaekong ◽  
Chaikarn Liewhiran ◽  
Sukon Phanichphant
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Nitrogen Adsorption ◽  
Average Diameter ◽  
Cuo Nanoparticles ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Copper oxide (CuO) nanoparticles were successfully synthesized by a thermal method. The CuO nanoparticles were further characterized by thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), and high resolution transmission electron microscopy (HRTEM), respectively. The specific surface area (SSABET) of CuO nanoparticles was determined by nitrogen adsorption. TheSSABETwas found to be 99.67 m2/g (dBETof 9.5 nm). The average diameter of the spherical CuO nanoparticles was approximately 6–9 nm.

Nanostructure and mechanical properties of WC–SiC thin films

2002 ◽  
Vol 17 (12) ◽  
pp. 3163-3167 ◽  
Author(s):  
Jose L. Endrino ◽  
James E. Krzanowski
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hardness Increase ◽  
Carbide Content

The mechanical properties of WC–SiC thin films deposited by dual radio frequency magnetron sputtering were investigated. The films were characterized by x-ray photoelectron spectroscopy, x-ray diffraction (XRD), and transmission electron microscopy (TEM) to evaluate the details of the microstructure and degree of amorphization. The results indicate that small additions of SiC (<25%) can significantly increase hardness compared to a pure WC film, but higher SiC contents do not strongly affect hardness. XRD studies show the SiC had a disordering effect. TEM results showed that WC films had coarse porous structure, but films with a low silicon carbide content (approximately 10 to 25 at%) had a denser nanocrystalline structure. Samples with greater than 25% SiC were amorphous. The initial hardness increase at lower SiC contents correlated well with the observed densification, but the transition to an amorphous structure did not strongly affect hardness.

scholarly journals Graphene Oxide/Ferrocene-Containing Polymer/Gold Nanoparticle Triple Nanocomposite

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 310 ◽  
Author(s):  
Wenhao Qian ◽  
Tao Song ◽  
Mao Ye ◽  
Haiyan Zhang ◽  
Chun Feng ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Colloidal Stability ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Methacrylate Monomer ◽  
Multifunctional Nanocomposites

A facile strategy to prepare GO-based nanocomposites with both gold nanoparticles (AuNPs) and ferrocene (Fc) moieties was developed. The surface of GO was modified with PFcMAss homopolymer by surface-initiated atom transfer radical polymerization of a new methacrylate monomer of 2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocene-carboxylate (FcMAss), consisting of disulfide as an anchoring group for stabilizing AuNPs and Fc group as an additional functionality. AuNPs with an average diameter of about 4.1 nm were formed in situ on the surface of PFcMAss-decorated GO (GO-PFcMAss) via Brust-Schiffrin method to give GO-PFcMAss-AuNPs multifunctional nanocomposites bearing GO, AuNPs and Fc groups. The obtained nanocomposites were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Since disulfide-containing polymers, rather than the commonly used thiol-containing compounds, were employed as ligands to stabilize AuNPs, much more stabilizing groups were attached onto the surface of GO, and thus more AuNPs were able to be introduced onto the surface of GO. Besides, polymeric chains on the surface of GO endowed GO-PFcMAss-AuNPs nanocomposites with excellent colloidal stability, and the usage of a disulfide group provides possibility to efficiently incorporate additional functionalities by easily modifying structure of disulfide-based monomer.

SYNTHESIS OF MONODISPERSE Mn3O4 NANOCRYSTALS

2009 ◽  
Vol 08 (03) ◽  
pp. 281-283 ◽  
Author(s):  
MASOUD SALAVATI-NIASARI ◽  
FATEMEH DAVAR
Keyword(s):  
Photoelectron Spectroscopy ◽  
Average Diameter ◽  
Binding Energies ◽  
X Ray Diffraction ◽  
Transmission Electron Microscopy Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
20 Nm

Mn3O4 nanocrystals have been prepared using [bis(2-hydroxyacetophenato)manganese(II)] as precursor. Transmission electron microscopy analysis demonstrated nanocrystals Mn3O4 with an average diameter of about 20 nm. The structural study by X-ray diffraction indicates that these nanocrystals have pure tetragonal phase. The phase pure samples were characterized using X-ray Photoelectron Spectroscopy for Mn 2p level. The values of binding energies are consistent with the relative values reported in the literature.

scholarly journals α-Cellulose Fibers of Paper-Waste Origin Surface-Modified with Fe3O4 and Thiolated-Chitosan for Efficacious Immobilization of Laccase

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 581
Author(s):  
Gajanan S. Ghodake ◽  
Surendra K. Shinde ◽  
Ganesh D. Saratale ◽  
Rijuta G. Saratale ◽  
Min Kim ◽  
...  
Keyword(s):  
Enzyme Immobilization ◽  
Photoelectron Spectroscopy ◽  
Cellulose Fibers ◽  
Relative Activity ◽  
Significant Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Laccase Immobilization ◽  
Surface Modified

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.

scholarly journals A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee
Keyword(s):  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
High Entropy Alloy ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Thin Film Resistors

Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR).

Sign in / Sign up

Export Citation Format

Share Document