Solid-State Combustion of Metallic Nanoparticles: New Possibilities for an Alternative Energy Carrier

2006 ◽  
Vol 129 (1) ◽  
pp. 29-32 ◽  
Author(s):  
D. B. Beach ◽  
A. J. Rondinone ◽  
B. G. Sumpter ◽  
S. D. Labinov ◽  
R. K. Richards
Keyword(s):  
Solid State ◽  
Metallic Nanoparticles ◽  
Alternative Energy ◽  
High Surface ◽  
Combustion Process ◽  
Volume Ratio ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Regeneration Cycle ◽  
Good Agreement

As an alternative to conventional methods of conveying and delivering energy in mobile applications or to remote locations, we have examined the combustion of nanostructured metal particles assembled into metal clusters. Clusters containing iron nanoparticles (∼50nm in diameter) were found to combust entirely in the solid state due to the high surface-to-volume ratio typical of nanoparticles. Optical temperature measurements indicated that combustion was rapid (∼500ms), and occurred at relatively low peak combustion temperatures (1000-1200K). Combustion produces a mixture of Fe(III) oxides. X-ray diffraction and gravimetric analysis indicated that combustion was nearly complete (93–95% oxidation). Oxide nanoparticles could be readily reduced at temperatures between 673K and 773K using hydrogen at 1atm pressure, and then passivated by the growth of a thin oxide layer. The nanostructuring of the particles is retained throughout the combustion–regeneration cycle. Modeling of the combustion process is in good agreement with observed combustion characteristics.

Structural and Optical Studies of CdS Nanocomposites Synthesized by Various Routes

2008 ◽  
Vol 8 (8) ◽  
pp. 4188-4192 ◽  
Author(s):  
Gouri Sankar Paul ◽  
Pratima Agarwal
Keyword(s):  
Quantum Confinement Effect ◽  
High Surface ◽  
Aqueous Media ◽  
Thermo Gravimetric Analysis ◽  
Volume Ratio ◽  
Stoichiometric Ratio ◽  
Particle Sizes ◽  
Gravimetric Analysis ◽  
Phonon Modes ◽  
Cds Nanocomposites

Structural and optical properties of CdS nanocomposites prepared by two different routes are presented in this paper. While CdS prepared by aqueous media results in the formation of nanoparticles of particle sizes 8–9 nm; the solvothermal process results in the formation of nanorods of diameter 40–50 nm and length 450–750 nm where particle sizes were confirmed by SEM and TEM. XRD studies confirm that the structure of these nanocomposites is wurzite. EDAX give the stoichiometric ratio. UV-Vis and photoluminescence (PL) measurements show a blue shift compared to bulk CdS, supporting quantum confinement effect. Nanocomposites are found to be stable up to 650 °C was observed by thermo gravimetric analysis (TGA). The Raman scattering studies show that in addition to LO and TO phonon modes, peak corresponding to surface phonon modes are present in both cases, which are due to high surface to volume ratio. The CdS nanocomposites can therefore be used for various stable optoelectronic devices.

Physical and Thermal Properties of Chitosan

2014 ◽  
Vol 979 ◽  
pp. 315-318 ◽  
Author(s):  
W. Siriprom ◽  
K. Chantarasunthon ◽  
K. Teanchai
Keyword(s):  
Physical Properties ◽  
Thermo Gravimetric Analysis ◽  
Raw Material ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Biodegradable Films ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Good Agreement

This work aims at characterizing the thermal and physical properties of chitosan. The samples were evaluated for potentiality to use as raw material for biodegradable films raw material. Their thermal and physical properties have been also discussed in detail which Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA), Energy Dispersive X-Ray Fluorescence (EDXRF) and X-Ray Diffraction (XRD), respectively. The result of the XRD pattern indicated the sample has amorphous-crystalline structure and FTIR results confirmed the formation of intermolecular hydrogen bonding between the amino and hydroxyl groups of the sample. In good agreement between the EDXRF and TGA results, noticed that the removal of moisture and volatile material.

Solid-state and solution 117Sn NMR study of C2O4(SnPh3)2: a revision

2011 ◽  
Vol 34 (5-6) ◽  
pp. 153-153
Author(s):  
Libasse Diop
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Magnetic Resonance ◽  
State Structure ◽  
X Ray Diffraction ◽  
Magnetic Resonance Studies ◽  
X Ray ◽  
Nmr Study ◽  
Tetrahedral Environment ◽  
Good Agreement

Abstract Solid-state and solution 117Sn nuclear magnetic resonance studies of C2O4(SnPh3)2 have been carried out and found to be in good agreement with the tetrahedral environment of the tin (IV) atom as found from the solid state structure, previously determined by a single crystal X-ray diffraction analysis.

Solid state properties of poly-β-hydroxybutyrate and of its oligomers

1981 ◽  
Vol 59 (1) ◽  
pp. 38-44 ◽  
Author(s):  
R. H. Marchessault ◽  
Suzanne Coulombe ◽  
Hiromichi Morikawa ◽  
Keizo Okamura ◽  
J. F. Revol
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Single Crystals ◽  
Small Angle ◽  
X Ray Diffraction ◽  
Melting Points ◽  
X Ray ◽  
Structure Factors ◽  
Electron Diffractograms ◽  
Good Agreement

The solid state properties of poly-β-hydroxybutyrate (PHB) were investigated for samples with degrees of polymerization [Formula: see text] from 4 to 994. The observed melting points ranged from 47 °C to 180 °C. Electron diffractograms on carefully prepared single crystals of a high molecular weight sample provided data which confirmed the reported a and b parameters from X-ray fiber diffraction and provided clear justification for the P212121 space group. The observed intensities in the electron diffractogram, corresponding to (hk0) reflections, were compared with the predicted intensities for two proposed structures in the literature. The observed and calculated structure factors for both structures were in good agreement. Small angle X-ray diffraction of the meridional maximum for annealed "cold drawn" and "hot drawn" fibers showed a distinctly different dependence on temperature than the maximum for stacks of lamellar single crystals. For oligomers a long spacing was observed which was about twice the length of the sample [Formula: see text] multiplied by the crystalline advance per monomer.

scholarly journals Preparation of Zirconium Oxide Powder Using Zirconium Carboxylate Precursors

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammed H. Al-Hazmi ◽  
YongMan Choi ◽  
Allen W. Apblett
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Dissociative Adsorption ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Experimental Findings ◽  
Periodic Dft Calculations ◽  
Good Agreement

Zirconia was prepared at low temperatures (<450°C) using single several source precursors based on zirconium carboxylates where the R groups were systematically varied. The combination of density functional theory (DFT) calculations and extensive characterization of the precursors (i.e., X-ray diffraction, thermal gravimetric analysis, infrared spectroscopy, and scanning electron microscopy) indicated that the carboxylic acid complexes may link the zirconium metal with a cis bidentate configuration. Periodic DFT calculations were performed to examine the interaction between monoclinic ZrO2 and propanoic acid. Dissociative adsorption takes place through the cis bidentate structure with an adsorption energy of −1.43 eV. Calculated vibrational frequencies using the optimized structure are in good agreement with experimental findings.

Charge induced Variation of the Magnetization in Nanoporous Ni-Pd

2005 ◽  
Vol 876 ◽  
Author(s):  
Christian Lemier ◽  
Sadhan Ghosh ◽  
R. N. Viswanath ◽  
Guang-Tao Fei ◽  
Jörg Weissmüller
Keyword(s):  
Space Charge ◽  
High Surface ◽  
Volume Ratio ◽  
X Ray Diffraction ◽  
Noticeable Effect ◽  
Surface Charging ◽  
Nanoporous Metal ◽  
Nanoporous Metals ◽  
Effect Of Surface ◽  
Considerable Strain

AbstractChanges in the electronic structure in superficial space-charge regions may substantially affect the properties of metals near their surface. In materials with a nanoscale porosity and with a high surface to volume ratio, changes in the properties of even a thin surface layer may have a noticeable effect on the properties of the entire material. In nanoporous metals immersed in an electrolyte, the space charge can be induced as a part of the electric double layer at the metal-electrolyte interface. Here we present first experiments on the effect of surface charging in a nanoporous metal on the magnetism. We report reversible changes in the magnetic moment in Ni-Pd alloys. As possible origins of the dependency of the magnetization on the surface charge density we discuss band filling and, alternatively, magnetostriction. X-ray diffraction and dilatometry reveal a considerable strain amplitude, about of 6×10-4, resulting from surface charging; this corresponds to a surface-induced pressure in the crystal lattice, in the order of 0.3 GPa.

Doping of Palladium in Silica Nanofibers via Electrospinning and Sol-Gel Synthesize as Hydrogen Storage Material

2011 ◽  
Vol 471-472 ◽  
pp. 1040-1045 ◽  
Author(s):  
Samaneh Shahgaldi ◽  
Zahira Yaakob ◽  
Dariush Jafar Khadem ◽  
Wan Ramli Wan Daud ◽  
Edy Herianto Majlan
Keyword(s):  
Hydrogen Storage ◽  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
High Surface Area ◽  
Chemical Vapour ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Silica Nanofibers

In recent years, one dimensional nanostructure, nanowires, nanofibers with unique properties have been a subject of intense research due to reduction of devise dimension, potential properties from the re-arrangement at the molecular level and high surface area. There are many methods for synthesize such as laser ablation, chemical vapour deposition, solution method micro pulling down method but all these method faced to the major disadvantages of being complicated with long wasting time and relatively high expense . The electrospinning recently used for producing ceramic, metal, and carbon nanofibers. In this report, we incorporate palladium into silica nanofibers for the first time, and the effect of doping of palladium into the silica nanofibers is investigated. The different ratio of palladium to silica and comparing with silica nanofibers is also reported. The composition, morphology, structure and surface area of silica, and silica palladium nanofibers were investigated by thermo gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FT-IR), and Micromeriics. To the best of our knowledge, investigation on characteristic on Silica palladium nanofibers has not been reported up to now. The result reveal that the silica nanofibers compare to silica doped with palladium have lower diameter, and also by increasing the temperature above 600 °C, the reduction in length of nanofibers happened. High surface area of silica palladium nanofibers can be one of the promising materials for hydrogen storage.

scholarly journals Synthesis of Wollastonite Powders by Combustion Method: Role of Amount of Fuel

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Imarally V. de S. R. Nascimento ◽  
Willams T. Barbosa ◽  
Raúl G. Carrodeguas ◽  
Marcus V. L. Fook ◽  
Miguel A. Rodríguez
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Combustion Process ◽  
Calcium Nitrate ◽  
Combustion Method ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Solution Combustion

The objective of this work has been the synthesis of wollastonite by solution combustion method. The novelty of this work has been obtaining the crystalline phase without the need of thermal treatments after the synthesis. For this purpose, urea was used as fuel. Calcium nitrate was selected as a source of calcium and colloidal silica served as a source of silicon. The effect of the amount of fuel on the combustion process was investigated. Temperature of the combustion reaction was followed by digital pyrometry. The obtained products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and specific surface area. The results showed that the combustion synthesis provides nanostructured powders characterized by a high surface area. When excess of urea was used, wollastonite-2M was obtained with a submicronic structure.

scholarly journals Synthesis and structural analysis of polynuclear silver(I) complexes with 4,7-phenanthroline

2019 ◽  
Vol 84 (7) ◽  
pp. 689-699 ◽  
Author(s):  
Ivana Stanojevic ◽  
Nada Savic ◽  
Aurélien Crochet ◽  
Katharina Fromm ◽  
Milos Djuran ◽  
...  
Keyword(s):  
Solid State ◽  
Room Temperature ◽  
Volume Ratio ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bridging Ligand ◽  
Coordination Sites ◽  
Hydrolysis Of

New polynuclear silver(I) complexes, [Ag(CF3SO3)(4,7-phen)(CH3CN)]n (1) and [Ag(PO2F2)(4,7-phen)]n (2), were synthesized by the reaction of 4,7-phenanthroline (4,7-phen) and the corresponding AgX salt (X = CF3SO3 - and PF6 -) in 1:2 mole ratio, respectively, in methanol/acetone (1:1 volume ratio) at room temperature. The characterization of the complexes was established on the basis of elemental microanalysis, IR and NMR (1H and 13C) spectroscopic techniques, while their crystal structures were determined by single-crystal X-ray diffraction analysis. The results of spectroscopic and crystallographic analyses revealed that in these complexes, 4,7-phen behaves as a bridging ligand between two metal ions, while the remaining coordination sites of the Ag(I) ions are occupied by the oxygen atom of CF3SO3 - and an acetonitrile nitrogen atom in 1 or by two oxygen atoms from two PO2F2 -, formed after hydrolysis of PF6 -, in 2. In the solid state, both complexes are coordination polymers in which the geometry around the Ag(I) ions is distorted tetrahedral.

Connected Electrodes by the Growth of Germanium Dioxide Nanowires

2006 ◽  
Vol 951 ◽  
Author(s):  
Chun-I Wu ◽  
Tim P. Hogan
Keyword(s):  
High Surface ◽  
Electronic Devices ◽  
Volume Ratio ◽  
Germanium Dioxide ◽  
Index Of Refraction ◽  
Lateral Growth ◽  
X Ray Diffraction ◽  
Catalyst Metal ◽  
Thermal Annealing Process ◽  
Metal Catalyzed

ABSTRACTGermanium dioxide nanowires have gained significant interest lately due to the the bandgap of 2.44 eV, and high index of refraction, n=1.63. In this paper we aim at investigating the lateral growth of high density metal-catalyzed germanium dioxide nanowires between electrodes. The gaps between two electrodes varied. The catalyst metal was placed on the electrodes, followed by a thermal annealing process, resulting in lateral growth of germanium dioxide whiskers with several microns length and eventually the formation of bridge-like nanostructures. These whiskers have certain unique properties, such as a high surface-to-volume ratio and the capability of connecting two electrodes. Because of these properties, the growth of whiskers from the electrodes has the potential to be developed as electronic devices such as nanosensors. These products are characterized by scanning electron microscopy (SEM), as well as X-Ray diffraction (XRD).

Sign in / Sign up

Export Citation Format

Share Document