Controlling nanostructure in thermal plasma processing: Moving from highly aggregated porous structure to spherical silica nanoparticles

Goortani, Behnam Mostajeran; Proulx, Pierre; Xue, Shaolin; Mendoza-Gonzalez, Norma Y.

doi:10.1016/j.powtec.2007.01.014

Cited by 32 publications

(23 citation statements)

References 18 publications

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“…The plasma processing conditions prevent then the formation of hard agglomerates. It has been already demonstrated that the adaptation of the quenching position and gas flow rate has an influence on the particle size [9,12,[15][16][17][18]. In this study, the quenching conditions used should additionally decrease the surface temperature of the nanoparticles below their sintering temperature as no sintering necks are formed; the PCS measurements are in agreement with the microscopic observations of the primary particles.…”

Section: Discussionsupporting

confidence: 81%

In Situ Treatment of Thermal RF Plasma Processed Nanopowders to Control their Agglomeration and Dispersability

Leparoux

Leconte

Wirth³

et al. 2010

Plasma Chem Plasma Process

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International audienceTitanium carbonitride nanoparticles have been produced in an inductively coupled thermal plasma and subsequently modified using a surfactant that has been deposited in situ on their surface in-flight. The surfactant was injected in the reactor while the nanoparticles are still dispersed in the gas phase, allowing the coating of primary particles instead of the corresponding agglomerates. In contrast to naked TiCN nanoparticles, the surfactant coated particles could be readily dispersed in water with a short ultrasonic treatment and built up no large agglomerates as proved by Photon Correlation Spectroscopy measurements. The investigated surfactants seem, however, to undergo a chemical modification and/or a thermal degradation at the surface of the TiCN nanoparticles

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Section: Discussionsupporting

confidence: 81%

In Situ Treatment of Thermal RF Plasma Processed Nanopowders to Control their Agglomeration and Dispersability

Leparoux

Leconte

Wirth³

et al. 2010

Plasma Chem Plasma Process

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“…Accordingly, numerical modeling was proved to be particularly adapted: computational fluid dynamic (CFD) permits to estimate the temperature and velocity fields in and outside the ICP torch (Ref [3][4][5][8][9][10][11][12][13][14][15][16][17][18][19][20]. In the present article, a two-dimensional axisymmetric model of the induction plasma was developed and used.…”

Section: Introductionmentioning

confidence: 99%

Modeling of an Inductively Coupled Plasma for the Synthesis of Nanoparticles

et al. 2007

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Among other methods, inductively coupled plasma (ICP) torches can be used for the synthesis of nanoparticles. In this process, the precursor material is vaporized in the first step in the plasma core. In the second step, nucleation and condensation occur in the synthesis chamber where the plasma gets colder and high-purity nanoparticles are synthesized, the growth of which is stopped by gas quenching. From their low velocity and high temperature, induction plasmas are particularly adapted for this application. Numerical modeling is a good way to achieve a better knowledge and understanding of the process since non-intrusive diagnostics are fairly difficult to implement. In the present article, a twodimensional model of an ICP torch was developed and validated on the basis of comparisons with data obtained by some other authors. Finally, the current frequency (13.56 MHz), pressure level (0.04 MPa), and gas flow rates were adjusted for the specific conditions of nanoparticles synthesis.

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“…In particular, its main effect is to generate a high cooling rate in the tail of the plasma, allowing for the synthesis of nanoparticles with a narrow PSD. In addition, the quenching configuration (type and position of the injection), together with the geometry of the reaction chamber, has been shown to affect the production rate and the properties of the synthetized nanoparticles [8,[13][14]. Quench gas injection operates with several hundred of standard litres per minute of inert gas, usually argon.…”

Section: Introductionmentioning

confidence: 99%

Design-Oriented Modelling of Different Quenching Solutions in Induction Plasma Synthesis of Copper Nanoparticles

Bianconi

Boselli

Gherardi

et al. 2017

Plasma Chem Plasma Process

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The aim of this paper is to compare the effects of different mechanisms underlying the synthesis of copper nanoparticles using an atmospheric pressure radiofrequency induction thermal plasma. A design oriented modelling approach was used to parametrically investigate trends and impact of different parameters on the synthesis process through a thermo-fluid dynamic model coupled with electromagnetic field equations for describing the plasma behaviour and a moment method for describing nanoparticles nucleation, growth and transport. The effect of radiative losses from Cu vapour on the precursor evaporation efficiency is highlighted, with occurrence of loading effect even with low precursor feed rate due to the decrease in plasma temperature. A method to model nanoparticle deposition on a porous wall is proposed, in which a sticking coefficient is employed to model particle sticking on the porous wall used to carry a quench gas flow into the chamber. Two different reaction chamber designs combined with different quench gas injection strategies (injection through a porous wall for "active" quenching; injection of a shroud gas for "passive" quenching) are analysed in terms of process yield and size distribution of the synthetized nanoparticles. Conclusion can be drawn on the characteristics of each quenching strategy in terms of throughput and mean diameter of the synthesized nanoparticles.

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Controlling nanostructure in thermal plasma processing: Moving from highly aggregated porous structure to spherical silica nanoparticles

Cited by 32 publications

References 18 publications

In Situ Treatment of Thermal RF Plasma Processed Nanopowders to Control their Agglomeration and Dispersability

In Situ Treatment of Thermal RF Plasma Processed Nanopowders to Control their Agglomeration and Dispersability

Modeling of an Inductively Coupled Plasma for the Synthesis of Nanoparticles

Design-Oriented Modelling of Different Quenching Solutions in Induction Plasma Synthesis of Copper Nanoparticles

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