Growth mechanism of silicon-based functional nanoparticles fabricated by inductively coupled thermal plasmas

Abstract

An experimental and computational study is conducted for the Si-based functional nanoparticle fabrication in an inductively coupled thermal plasma reactor. In the computational study, the improved multi-component co-condensation model with nodal discretization is proposed to clarify the nanoparticle growth mechanism in the consideration of coagulation and thermophoresis as well as simultaneous co-condensation. The nanoparticle growth by nucleation and co-condensation completes approximately in 12.6 ms for the Mo–Si system and in 5.0 ms for the Ti–Si system. Mo nanoparticles grow in advance, and then Si vapour condenses on the Mo nanoparticles in the Mo–Si system, while vapours of Si and Ti simultaneously co-condense following Si nucleation in the Ti–Si system. A smaller number of larger nanoparticles are created with an increase in the powder feed rate. When the silicon content in the feed powders is 66.7%, nanoparticles of MSi2 (M = Mo, Ti) are fabricated as the main product. Nanoparticles of Ti5Si3 are mainly synthesized in the case of the silicon content 33.0%. In the experiment, the nanoparticles are successfully fabricated and examined by x-ray diffractometry and transmission electron microscopy. The experimental and computational results show good agreement in the size distribution and the composition.

Two-Directional Nodal Model for Co-Condensation Growth of Multicomponent Nanoparticles in Thermal Plasma Processing

“…From the top of the system, argon gas is injected as the carrier gas (1.0 Sl/min), the plasma supporting gas (3.0 Sl/min), and the sheath gas (30.0 Sl/min). These operating conditions are identical to those of the experiments (Ref 8,9), so that the numerical results and the experiment results can be compared for model verification.…”

“…Several experimental studies on silicide nanoparticle production by thermal plasmas have been conducted (Ref [5][6][7][8][9]. However, only the characteristics of the products were evaluated because of measurement limitations.…”

An innovative energy-saving in-flight melting technology and its application to glass production

“…Thermal plasmas have received considerable attention due to their unique advantages such as high enthalpy, high chemical reactivity, alterable oxidation or reduction atmosphere in accordance with required chemical reaction, easy and rapid generation of high temperatures, long residence time as well as rapid quenching rate [6]. Thermal plasmas, therefore, have been widely applied for material processing, such as the synthesis of nanoparticles, chemical vapor deposition (CVD) and plasma spraying [7][8][9]. High temperatures of thermal plasmas make it easy to melt raw glass powders quickly.…”

A Co-Condensation Model for In-Flight Synthesis of Metal-Carbide Nanoparticles in Thermal Plasma Jet

“…The use of thermal plasma spraying technique for production of nanopowders has been experimentally explored by several investigators (e.g., . Several theoretical analyses also have focused on the synthesis of nanoparticles in different plasma reactors ( Ref 1,[5][6][7][8][9][10][11]. Most of the theoretical work devoted to the synthesis of nanoparticles is, however, focused on the nucleation and growth of particles consisting of one component.…”