Synthesis of Inorganic Nanoparticles Via a Plasma/gas-phase Process

Synthesis of Inorganic Nanoparticles Via a Plasma/gas-phase Process PDF Author: Alicia T. F. Ng
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :

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Synthesis of Inorganic Nanoparticles Via a Plasma/gas-phase Process

Synthesis of Inorganic Nanoparticles Via a Plasma/gas-phase Process PDF Author: Alicia T. F. Ng
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :

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Synthesis and Morphological Evolution of Inorganic Nanoparticles in Gas Phase Flames

Synthesis and Morphological Evolution of Inorganic Nanoparticles in Gas Phase Flames PDF Author: Yangchuan Xing
Publisher:
ISBN:
Category :
Languages : en
Pages : 426

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Gas-Phase Synthesis of Nanoparticles

Gas-Phase Synthesis of Nanoparticles PDF Author: Yves Huttel
Publisher: John Wiley & Sons
ISBN: 3527340602
Category : Technology & Engineering
Languages : en
Pages : 416

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Book Description
The first overview of this topic begins with some historical aspects and a survey of the principles of the gas aggregation method. The second part covers modifications of this method resulting in different specialized techniques, while the third discusses the post-growth treatment that can be applied to the nanoparticles. The whole is rounded off by a review of future perspectives and the challenges facing the scientific and industrial communities. An excellent resource for anyone working with the synthesis of nanoparticles, both in academia and industry.

Gas-Phase Synthesis of Nanoparticles

Gas-Phase Synthesis of Nanoparticles PDF Author: Yves Huttel
Publisher: John Wiley & Sons
ISBN: 352769840X
Category : Technology & Engineering
Languages : en
Pages : 420

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Book Description
The first overview of this topic begins with some historical aspects and a survey of the principles of the gas aggregation method. The second part covers modifications of this method resulting in different specialized techniques, while the third discusses the post-growth treatment that can be applied to the nanoparticles. The whole is rounded off by a review of future perspectives and the challenges facing the scientific and industrial communities. An excellent resource for anyone working with the synthesis of nanoparticles, both in academia and industry.

Metal Oxide Nanoparticles, 2 Volume Set

Metal Oxide Nanoparticles, 2 Volume Set PDF Author: Oliver Diwald
Publisher: John Wiley & Sons
ISBN: 1119436745
Category : Technology & Engineering
Languages : de
Pages : 903

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Book Description
Metal Oxide Nanoparticles A complete nanoparticle resource for chemists and industry professionals Metal oxide nanoparticles are integral to a wide range of natural and technological processes—from mineral transformation to electronics. Additionally, the fields of engineering, electronics, energy technology, and electronics all utilize metal oxide nanoparticle powders. Metal Oxide Nanoparticles: Formation, Functional Properties, and Interfaces presents readers with the most relevant synthesis and formulation approaches for using metal oxide nanoparticles as functional materials. It covers common processing routes and the assessment of physical and chemical particle properties through comprehensive and complementary characterization methods. This book will serve as an introduction to nanoparticle formulation, their interface chemistry and functional properties at the nanoscale. It will also act as an in-depth resource, sharing detailed information on advanced approaches to the physical, chemical, surface, and interface characterization of metal oxide nanoparticle powders and dispersions. Addresses the application of metal oxide nanoparticles and its economic impact Examines particle synthesis, including the principles of selected bottom-up strategies Explores nanoparticle formulation—a selection of processing and application routes Discusses the significance of particle surfaces and interfaces on structure formation, stability and functional materials properties Covers metal oxide nanoparticle characterization at different length scales With this valuable resource, academic researchers, industrial chemists, and PhD students can all gain insight into the synthesis, properties, and applications of metal oxide nanoparticles.

Process Design for Plasma-Based Gas-Phase Nucleation of Carbon Nanoparticles

Process Design for Plasma-Based Gas-Phase Nucleation of Carbon Nanoparticles PDF Author: Jonathan Cole
Publisher:
ISBN:
Category : Carbon
Languages : en
Pages : 146

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Book Description
This thesis project is focused on designing plasma processes for the controlled synthesis of nanoscale forms of crystalline carbon. The general mechanism for all the plasma systems is homogeneous nucleation, which describes the formation of nanoparticles in the gas-phase from vapor precursors. Nucleation from a preexisting seed particle is also explored, which is similar to heterogeneous nucleation on a substrate except that in some cases nucleation of the seed itself occurs within a gas flow.The first type of plasma system that was studied is a direct-current (DC), atmospheric-pressure microplasma that effectively limits particle growth so that nanosized (

Controlling the growth of nanoparticles produced in a high power pulsed plasma

Controlling the growth of nanoparticles produced in a high power pulsed plasma PDF Author: Rickard Gunnarsson
Publisher: Linköping University Electronic Press
ISBN: 9176854663
Category :
Languages : en
Pages : 69

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Book Description
Nanotechnology can profoundly benefit our health, environment and everyday life. In order to make this a reality, both technological and theoretical advancements of the nanomaterial synthesis methods are needed. A nanoparticle is one of the fundamental building blocks in nanotechnology and this thesis describes the control of the nucleation, growth and oxidation of titanium particles produced in a pulsed plasma. It will be shown that by controlling the process conditions both the composition (oxidationstate) and size of the particles can be varied. The experimental results are supported by theoretical modeling. If processing conditions are chosen which give a high temperature in the nanoparticle growth environment, oxygen was found to be necessary in order to nucleate the nanoparticles. The two reasons for this are 1: the lower vapor pressure of a titanium oxide cluster compared to a titanium cluster, meaning a lower probability of evaporation, and 2: the ability of a cluster to cool down by ejecting an oxygen atom when an oxygen molecule condenses on its surface. When the oxygen gas flow was slightly increased, the nanoparticle yield and oxidation state increased. A further increase caused a decrease in particle yield which is attributed to a slight oxidation ofthe cathode. By varying the oxygen flow, it was possible to control the oxidation state of the nanoparticles without fully oxidizing the cathode. Pure titanium nanoparticles could not be produced in a high vacuum system because oxygen containing gases such as residual water vapour have a profound influence on nanoparticle yield and composition. In an ultrahigh vacuum system titanium nanoparticles without significantoxygen contamination were produced by reducing the temperature of the growth environment and increasing the pressure of an argon-helium gas mixture within whichthe nanoparticles grew. The dimer formation rate necessary for this is only achievable at higher pressures. After a dimer has formed, it needs to grow by colliding with a titanium atom followed by cooling by collisions with multiple buffer gas atoms. The condensation event heats up the cluster to a temperature much higher than the gas temperature, where it is during a short time susceptible to evaporation. When the clusters’ internal energy has decreased by collisions with the gas to less than the energy required to evaporate a titanium atom, it is temporarily stable until the next condensation event occurs. The temperature difference by which the cluster has to cool down before it is temporarily stable is exactly as many kelvins as the gas temperature.The addition of helium was found to decrease the temperature of the gas, making it possible for nanoparticles of pure titanium to grow. The process window where this is possible was determined and the results presented opens up new possibilities to synthesize particles with a controlled contamination level and deposition rate.The size of the nanoparticles has been controlled by three means. The first is to change the electrical potential around the growth zone, which allows for size (diameter) control in the order of 25 to 75 nm without influencing the oxygen content of the particles. The second means is by increasing the pressure which decreases the ambipolar diffusion rate of the ions resulting in a higher growth material density. By doing this, the particle size can be increased from 50 to 250 nm, however the oxygen content also increases with increasing pressure when this is done in a high vacuum system. The last means of size control was by adding a helium flow to the process where higher flows resulted in smaller nanoparticle sizes. When changing the pressure in high vacuum, the morphology of the nanoparticles could be controlled. At low pressures, highly faceted near spherical particles were produced. Increasing the pressure caused the formation of cubic particles which appear to ‘fracture’ at higher pressures. At the highest pressure investigated, the particles became poly-crystalline with a cauliflower shape and this morphology was attributed to a lowad atom mobility. The ability to control the size, morphology and composition of the nanoparticles determines the success of applying the process to manufacture devices. In related work presented in this thesis it is shown that 150-200 nm molybdenum particles with cauliflower morphology were found to scatter light in which made them useful in photovoltaic applications, and the size of titanium dioxide nanoparticles were found to influence the selectivity of graphene based gas sensors.

Inorganic Particle Synthesis via Macro and Microemulsions

Inorganic Particle Synthesis via Macro and Microemulsions PDF Author: Dibyendu Ganguli
Publisher: Springer Science & Business Media
ISBN: 1461500478
Category : Science
Languages : en
Pages : 214

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Book Description
"Nanotechnology" is now very well known as one of the most important key technologies in science and industry. In the field of material science and engineering, nanoparticles should be unit materials, as well as atoms and molecules, to build ceramics, devices, catalysts, and machines, and the "nanoparticle technology" is thus attracting. This novel technology includes various methodologies for nanoparticles: preparation, surface-modification via chemical and/or physical treatments, immobilization and arrangement on supports or substrates, to achieve high performance for luminescence properties in light emitting devices, and high efficiency for catalytic and photocatalytic reactions in chemical synthesis, chemical decomposition, and artificial photosynthesis, etc. It should be needless to say that the preparation of nanoparticles, having precisely controlled particle size, size distribution, chemical composition, and surface properties, is essentially important to realize "true nanoparticle technology". This book, written by Dr. Dibyendu Ganguli and Dr. Munia Ganguli, deals with the preparation methodologies for inorganic nanoparticles using macro- and microemulsions as "microreactor". There are several differences between these two emulsions, in addition to water droplet size: thermodynamic stability, and fusion-redispersion dynamics of the droplets. The properties of the nanoparticles prepared in these emulsion systems are seriously influenced and controlled by the selection of dynamic and static conditions.

Plasma based Synthesis and Modification of Nanomaterials

Plasma based Synthesis and Modification of Nanomaterials PDF Author: Pawel Pohl
Publisher: MDPI
ISBN: 3039213954
Category : Medical
Languages : en
Pages : 160

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Book Description
This book, entitled “Plasma-Based Synthesis and Modification of Nanomaterials” is a collection of nine original research articles devoted to the application of different atmospheric pressure (APPs) and low-pressure (LPPs) plasmas for the synthesis or modification of various nanomaterials (NMs) of exceptional properties. These articles also show the structural and morphological characterization of the synthesized NMs and their further interesting and unique applications in different areas of science and technology. The readers interested in the capabilities of plasma-based treatments will quickly be convinced that APPs and LPPs enable one to efficiently synthesize or modify differentiated NMs using a minimal number of operations. Indeed, the presented procedures are eco-friendly and usually involve single-step processes, thus considerably lowering labor investment and costs. As a result, the production of new NMs and their functionalization is more straightforward and can be carried out on a much larger scale compared to other methods and procedures involving complex chemical treatments and processes. The size and morphology, as well as the structural and optical properties of the resulting NMs are tunable and tailorable. In addition to the desirable and reproducible physical dimensions, crystallinity, functionality, and spectral properties of the resultant NMs, the NMs fabricated and/or modified with the aid of APPs are commonly ready-to-use prior to their specific applications, without any initial pre-treatments.

Supersonic Thermal Plasma Expansion Process for Nanoparticle Synthesis

Supersonic Thermal Plasma Expansion Process for Nanoparticle Synthesis PDF Author: Biswajit Bora
Publisher: LAP Lambert Academic Publishing
ISBN: 9783848444762
Category :
Languages : en
Pages : 184

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Book Description
Thermal arc plasma is one of the most preferred processing medium for synthesis of nanocrystalline materials in bulk quantities. The extremely high temperature, good crystallinity, sharp heating/cooling rates, relatively compact reactor size, appearance of non equilibrium phases in extremely fine particles are the highlights of this method. In this experiment, a segmented plasma torch, a special variety of non-transferred plasma torch is used, which produces highly stable plasma and constricts the flame better to produce higher ion density ensuring good reaction kinetics. A novel thermal plasma assisted technique i.e. supersonic thermal plasma expansion process is used for synthesis ceramic materials, in the form of crystalline nanoparticles. The reactants in gas phase are injected into plasma jet, which then expands to supersonic velocity, while moving through a converging nozzle, into a sample collection chamber maintained at lower pressure. The expansion produces a one-dimensional temperature gradient along the flow and negligible boundary layer irregularities, ensuring particle condensation in gas phase with narrow size dispersion.