Synthesis and Characterization of Silica Nanoparticles

2007 ◽  
Vol 121-123 ◽  
pp. 49-52 ◽  
Author(s):  
R. Aghababazadeh ◽  
S. Tabatabae ◽  
Ali Shokuhfar ◽  
A.R. Mirhabibi
Keyword(s):  
Electron Microscopy ◽  
Silica Nanoparticles ◽  
Silica Particles ◽  
Alcoholic Solution ◽  
Chemical System ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Monodisperse Colloidal Silica

Currently there are several models discussed to describe the formation of monodispersed silica particles. Monodisperse colloidal silica was prepared from tetraethoxysilane in mixture of ammonia, water and ethanol. Chemical system reaction permits the controlled growth of silica nanoparticles and subsequent condition of silicic acid in alcoholic solution. The molar ratio of NH4OH, C2H5OH and H2O has a significant effect on particle size and specific surface area of silica particles. The nature of particles was evaluated using X-ray diffraction, energy dispersive spectroscopy (EDS) and BET. The morphology of particles were determined by scanning electron microscopy (SEM) and transmission electron microscopy(TEM).

Detonation Synthesis of Nano-Size Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Detonation Synthesis ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

scholarly journals Preparation and Characterization of Polyhydroxybutyrate/Polycaprolactone Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Cha Ping Liau ◽  
Mansor Bin Ahmad ◽  
Kamyar Shameli ◽  
Wan Md Zin Wan Yunus ◽  
Nor Azowa Ibrahim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Basal Spacing ◽  
Cooh Group ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Ion Exchange Reaction ◽  
Transmission Electron ◽  
Matrix Enhancement ◽  
Double Hydroxide

Polyhydroxybutyrate (PHB)/polycaprolactone (PCL)/stearate Mg-Al layered double hydroxide (LDH) nanocomposites were prepared via solution casting intercalation method. Coprecipitation method was used to prepare the anionic clay Mg-Al LDH from nitrate salt solution. Modification of nitrate anions by stearate anions between the LDH layers via ion exchange reaction. FTIR spectra showed the presence of carboxylic acid (COOH) group which indicates that stearate anions were successfully intercalated into the Mg-Al LDH. The formation of nanocomposites only involves physical interaction as there are no new functional groups or new bonding formed. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that the mixtures of nanocomposites are intercalated and exfoliated types. XRD results showed increasing of basal spacing from 8.66 to 32.97 Å in modified stearate Mg-Al LDH, and TEM results revealed that the stearate Mg-Al LDH layers are homogeneously distributed in the PHB/PCL polymer blends matrix. Enhancement in 300% elongation at break and 66% tensile strength in the presence of 1.0 wt % of the stearate Mg-Al LDH as compare with PHB/PCL blends. Scanning electron microscopy (SEM) proved that clay improves compatibility between polymer matrix and the best ratio 80PHB/20PCL/1stearate Mg-Al LDH surface is well dispersed and stretched before it breaks.

Synthesis and characterization of homogeneous lead-substituted tin oxide with the (110) face of rutile structure

2000 ◽  
Vol 15 (10) ◽  
pp. 2076-2079
Author(s):  
Chika Nozaki ◽  
Takashi Yamada ◽  
Kenji Tabata ◽  
Eiji Suzuki
Keyword(s):  
Electron Microscopy ◽  
Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Rutile Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Synthesis of a rutile-type lead-substituted tin oxide with (110) face was investigated. The characterization was performed by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, infrared spectroscopy, x-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller surface area measurements. The homogeneous rutile-type lead-substituted tin oxide was obtained until 4.1 mol% of tin was substituted with lead. The surface of obtained oxide had a homogeneously lead-substituted (110) face.

scholarly journals An Efficient and Novel Ammonia Sensor Based on Polypyrrole/Tin Oxide/MWCNT Nanocomposite

2020 ◽  
Vol 32 (6) ◽  
pp. 1505-1510
Author(s):  
Ahmad Husain ◽  
Mohd Urooj Shariq ◽  
Anees Ahmad
Keyword(s):  
Electron Microscopy ◽  
Tin Oxide ◽  
Charge Carriers ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Ammonia Sensing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

In present study, the synthesis and characterization of a novel polypyrrole (PPy)/tin oxide (SnO2)/MWCNT nanocomposite along with pristine polypyrrole is reported. These materials have been studied for their structural and morphological properties by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. PPy/SnO2/MWCNT nanocomposite has been converted into a pellet-shaped sensor, and its ammonia sensing studies were carried out by calculating the variation in the DC electrical conductivity at different concentration of ammonia ranging from 10 to 1500 ppm. The sensing response of the sensor was determined at 1500, 1000, 500, 200, 100 and 10 ppm and found to be 70.4, 66.1, 62.2, 55.4, 50.8 and 39.7%, respectively The sensor showed a complete reversibility at lower concentrations along with excellent selectivity and stability. Finally, a sensing mechanism was also proposed involving polarons (charge carriers) of polypyrrole and lone pairs of ammonia molecules

Characterization of Fe–Ni(C) nanocapsules synthesized by arc discharge in methane

1999 ◽  
Vol 14 (5) ◽  
pp. 1782-1790 ◽  
Author(s):  
X. L. Dong ◽  
Z. D. Zhang ◽  
S. R. Jin ◽  
W. M. Sun ◽  
X. G. Zhao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Arc Discharge ◽  
Carbon Layer ◽  
Magnetization Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Energy Disperse Spectroscopy

Ultrafine Fe–Ni(C) particles of various compositions were prepared by arc discharge synthesis in a methane atmosphere. The particles were characterized by x-ray diffraction, transmission electron microscopy, energy disperse spectroscopy, chemical analysis, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and magnetization measurement. The carbon atoms solubilizing at interstitial sites in γ–(Fe, Ni, C) solution particles have the effects of forming austenite structure and changing microstructures as well as magnetic properties. A carbon layer covers the surface of Fe–Ni(C) particles to form the nanocapsules and protect them from oxidization. The mechanism of forming Fe–Ni(C) nanocapsules in the methane atmosphere was analyzed.

Microstructural Characterization of Pt/Ti and RuO2 Electrodes on SiO2/Si Annealed in the Oxygen Ambient

1996 ◽  
Vol 433 ◽  
Author(s):  
Jeong Soo Lee ◽  
Hyun JA Kwon ◽  
Young Woo Jeong ◽  
Hyun HA Kim ◽  
Kyu HO Park ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Film Surface ◽  
Microstructural Characterization ◽  
Silicide Phase ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Degree Of Oxidation ◽  
Thin Interlayer ◽  
Increasing Temperature

AbstractMicrostructures and interdiffusions of Pt/Ti/SiO2/Si and RuO2/SiO2/Si during annealing in O2 were investigated using x-ray diffraction, Auger electron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The degree of oxidation and the interdiffusion of elements have remarkably increased with increasing temperature above 500 °C for the Pt/Ti/SiO2/Si case. The generation of Pt hillocks commenced at 500 °C. The Pt-silicide phase was also observed near the TiOx/SiO2 interface. The microstructural variations occurred to only a small amount for the RuO2/SiO2/Si case over the temperature range 300 – 700 °C. While there was no hillock formation, the RuO2 film surface was roughened by the thermal grooving phenomenon. A thin interlayer phase was found at the RuO2/SiO2 interface.

scholarly journals Structural characterization of Yba2Cu3O7–δ/Y2O3 composite films

1998 ◽  
Vol 13 (4) ◽  
pp. 954-958 ◽  
Author(s):  
P. R. Broussard ◽  
M. A. Wall ◽  
J. Talvacchio
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Coincidence Site Lattice ◽  
Composite Films ◽  
X Ray Diffraction ◽  
Plane Orientation ◽  
Transmission Electron ◽  
Two Phases ◽  
High Degree

Using 4-circle x-ray diffraction and transmission electron microscopy, we have studied the microstructure and in-plane orientation of the phases present in thin film composite mixtures of Yba2Cu3O7–δ and Y2O3. We see a high degree of in-plane orientation and have verified a previous prediction for the in-plane order of Y2BaCuO5 on (110) MgO. Transmission electron microscopy shows the composite films to be a mixture of two phases, with YBCO grain sizes of ≈1 μm. We have also compared our observations of the in-plane order to the predictions of a modified near coincidence site lattice model.

scholarly journals Preparation and Characterization of Nanostructured Hollow MgO Spheres

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 537
Author(s):  
Jishuo Han ◽  
Guohua Li ◽  
Lin Yuan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Shell Thickness ◽  
Template Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Microsphere ◽  
Transmission Electron ◽  
Scanning Electron

Nanostructured hollow MgO microspheres were prepared by the template method. First, D-Anhydrous glucose was polymerized by the hydrothermal method to form a template. Second, a colorless solution was obtained by mixing magnesite with hydrochloric acid in a 1:2 proportion and heating in an 80 °C water bath for 2 h. Finally, the template from the first step was placed in the colorless solution, and the resulting precipitate was calcined at 550 °C for 2 h. The phase composition and microstructure of the calcined samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD results indicated that the main crystal is periclase. The SEM results indicates that the template carbon microsphere surface is smooth, and the its size is uniform and concentrated in the range of 100–200 nm. The diameters of the samples range from 60 to 90 nm, which is smaller than the size of the carbon microsphere. The TEM results indicates that the sample is hollow with a shell thickness of about 6–10 nm. The specific surface area of the calcined hollow sphere is 59.5 m²·g−1.

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