scholarly journals Photochemistry Aspects of the Laser Pyrolysis Addressing the Preparation of Oxide Semiconductor Photocatalysts

2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
R. Alexandrescu ◽  
I. Morjan ◽  
F. Dumitrache ◽  
M. Scarisoreanu ◽  
I. Soare ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Gas Phase ◽  
Anatase Phase ◽  
Iron Pentacarbonyl ◽  
Oxide Semiconductor ◽  
Iron Oxide Particles ◽  
Gamma Iron ◽  
Laser Pyrolysis ◽  
Synthesis Of Nanoparticles ◽  
Versatile Tool

The laser pyrolysis is a powerful and a versatile tool for the gas-phase synthesis of nanoparticles. In this paper, some fundamental and applicative characteristics of this technique are outlined and recent results obtained in the preparation of gamma iron oxide (γ-Fe2O3) and titania (TiO2) semiconductor nanostructures are illustrated. Nanosized iron oxide particles (4 to 9 nm diameter values) have been directly synthesized by the laser-induced pyrolysis of a mixture containing iron pentacarbonyl/air (as oxidizer)/ethylene (as sensitizer). Temperature-dependent Mossbauer spectroscopy shows that mainly maghemite is present in the sample obtained at higher laser power. The use of selectedFe2O3samples for the preparation of water-dispersed magnetic nanofluids is also discussed.TiO2nanoparticles comprising a mixture of anatase and rutile phases were synthesized via the laser pyrolysis ofTiCl4- (vapors) based gas-phase mixtures. High precursor concentration of the oxidizer was found to favor the prevalent anatase phase (about 90%) in the titania nanopowders.

Composition Influence on the Properties of Titanium-Doped Gamma Iron Oxide Nanoparticles Prepared by Laser Pyrolysis Method

2005 ◽  
Vol 872 ◽  
Author(s):  
Ion Morjan ◽  
Rodica Alexandrescu ◽  
Florian Dumitrache ◽  
Ion Sandu ◽  
Monica Scarisoreanu ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Titanium Tetrachloride ◽  
Analytical Techniques ◽  
Iron Pentacarbonyl ◽  
Powder Morphology ◽  
Gamma Iron ◽  
Laser Pyrolysis ◽  
Mean Grain Size ◽  
Compositional Characterization

AbstractThe aim of this work is the structural and sensing characterization of titanium-doped gamma iron oxide nanocomposites. These nanopowder materials were synthesized by the laser pyrolysis technique. It is based on the resonance between the emission of a CW CO2 laser line and the infrared absorption band of a gas (vapour) precursor. Basically, sensitised iron pentacarbonyl and titanium tetrachloride-based mixtures were used as gas-phase reactants. The compositional characterization of the synthesized nanostructures was performed by means of different analytical techniques. Introducing Ti in the Fe2O3 network in small quantities (< 1 %) seems to have little influence on titanium doped powder morphology (mean grain size ∼ 5nm) but increases the sensitivity of titanium doped iron oxide nanopowders with more then 20 % relatively to pure maghemite.

THE APPLICATION OF LASER IN THERMAL TREATMENT OF SOLID PARTICLES AND GAS-PHASE OF BIOMASS PROCESSING-A REVIEW

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Muhammad Mat Junoh ◽  
Farid Nasir Ani
Keyword(s):  
Renewable Energy ◽  
Gas Phase ◽  
Palm Oil ◽  
Elevated Temperatures ◽  
Solid Particles ◽  
Laser Technique ◽  
Synthesis Of Nanoparticles ◽  
Biomass Processing ◽  
Versatile Tool ◽  
The Government

Application of laser in heating technique of both organic gas-phase and solid particles for thermochemical decomposition at elevated temperatures in the absence of oxygen is presently a challenging area. Laser pyrolysis is a powerful and a versatile tool for the gas-phase synthesis of nanoparticles. Generally, the purpose of pyrolysis is not only for energy production but also for the production of chemical feedstocks. This paper reviews on the pyrolysis activities, generally in Malaysia and the utilization of laser in pyrolysis for renewable energy and materials application. Malaysia is a well-known for palm oil producer country in the world, generating significant wastes yearly from oil palm mills such as empty fruit brunch (EFB), shell, fiber and palm oil mill effluent (POME) has put the government to solve these wastes problem by doing research on the development of renewable energy and materials. This reviews concluded that there are new area of research for the utilization of waste material by using laser technique.

Production of Nanostructured Iron Oxide Particles via Aerosol Decomposition

1996 ◽  
Vol 457 ◽  
Author(s):  
J. Joutsensaari ◽  
E. I. Kauppinen
Keyword(s):  
Iron Oxide ◽  
Gas Phase ◽  
Phase Particle ◽  
Nitrate Solution ◽  
Processing Temperature ◽  
Iron Nitrate ◽  
Iron Oxide Particles ◽  
Oxide Particles ◽  
Electron Microscopes ◽  
Average Size

ABSTRACTNanostructured iron oxide particles with average size below 100 nm were produced by aerosol decomposition method starting from an aqueous iron nitrate solution. Air, nitrogen, or mixture of hydrogen (7 %) and nitrogen were used as the carrier gas. Gas-phase particle number size distributions were determined with a differential mobility analyzer. Particle morphology and crystallinity were studied with scanning (SEM) and transmission (TEM) electron microscopes. Crystalline phase composition of the particles was studied with X-ray diffraction (XRD). The average gas-phase diameter of particles produced in air or N2 reduced from 80 to 47 nm when temperature was increased from 500 to 1100 °C. In H2 rich environment, the reduction of average size was larger, from 80 nm at 500 °C to 45 nm already at 900 °C. SEM results showed that very small crystallites (5–10 nm) were formed on the surface of the particles produced in N2 at 500 °C. When the processing temperature was increased to 700, 900 and 1100 °C, the crystallites on the particle surfaces were grown to 15–30, 30–60 and 60–180 nm, respectively. TEM results show that very small particles (<50 nm) were single crystals and larger particles were polycrystalline with crystallite size of about 50 nm at 700 °C in H2/N2. Magnetite particles were produced from aqueous iron nitrate solution at 500 °C in H2/N2 and at 900 °C in N2 according to XRD results.

Advances in the laser pyrolysis synthesis of nanoparticles

2006 ◽  
Vol 31 (3) ◽  
pp. 295-315 ◽  
Author(s):  
Nathalie Herlin-Boime ◽  
Martine Mayne-L'Hermitte ◽  
Cécile Reynaud
Keyword(s):  
Laser Pyrolysis ◽  
Synthesis Of Nanoparticles ◽  
Pyrolysis Synthesis

scholarly journals Aqueous one-pot synthesis of well-defined zwitterionic diblock copolymers by RAFT polymerization: an efficient and environmentally-friendly route to a useful dispersant for aqueous pigments

2021 ◽  
Vol 23 (3) ◽  
pp. 1248-1258
Author(s):  
Shannon M. North ◽  
Steven P. Armes
Keyword(s):  
Iron Oxide ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Environmentally Friendly ◽  
Iron Oxide Particles ◽  
One Pot ◽  
One Pot Synthesis ◽  
Highly Effective ◽  
Oxide Particles

An atom-efficient, wholly aqueous one-pot synthesis of zwitterionic diblock copolymers has been devised. Such copolymers can serve as highly effective aqueous dispersants for nano-sized transparent yellow iron oxide particles.

Direct deposition of highly coercive gamma iron oxide thin films for magnetic recording

1993 ◽  
Vol 74 (11) ◽  
pp. 7019-7021 ◽  
Author(s):  
Sandip Dhara ◽  
A. C. Rastogi ◽  
B. K. Das
Keyword(s):  
Thin Films ◽  
Iron Oxide ◽  
Magnetic Recording ◽  
Oxide Thin Films ◽  
Gamma Iron ◽  
Direct Deposition
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