High quality single-walled carbon nanotubes (SWNT) have been synthesized at large scales by the method of direct evaporation of carbon black and metallic catalyst mixtures, using induction thermal plasma technology. The processing system consists mainly of an RF plasma torch, which generates a plasma jet of extremely high temperature (∼15 000 K), with a high energy density and abundance of reactive species (ions and neutrals). With the present reactor system, it has been demonstrated that carbon soot product which contains approximately 40 wt% of SWNT can be continuously synthesized at the high production rate of ∼100 g h−1. The processing parameters involved have been examined closely in order to evaluate their individual influences on SWNT synthesis. The results have shown that the quality and purity of the SWNT produced are critically affected by the grade of carbon black, the plasma gas composition and the metallic catalyst employed. Theoretical calculations, including thermodynamic and two-dimensional thermal flow analyses, have also been performed to determine the optimal process environment most suitable for SWNT synthesis and to obtain a better understanding of the effects of process parameters. Finally, product comparisons have been made against other reference materials using Raman spectroscopy, which has shown that the quality of thermal plasma-grown SWNT is superior to that of arc discharge-grown SWNT and approaches the quality of laser-grown SWNT. This result confirms that the induction thermal plasma technology developed in this work is one of the most promising methods for the production of high quality SWNT at large scales for commercial uses.
This literature review gives an overview of the lithium industry, including the lithium market, global resources, and processes of lithium compounds production. It focuses on the production of lithium compounds from spodumene minerals. Spodumene is one of the most critical minerals nowadays, due to its high lithium content and high rate of extraction. Lithium is one of the most sought-after metals, due to the ever-growing demand for lithium-ion batteries (LiBs). The data on lithium extraction from minerals is scattered through years of patents, journal articles, and proceedings; hence, requiring an in-depth review, including the comprehension of the spodumene phase system, the phase conversion processes, and the lithium extraction processes.
The production of high quality single-walled carbon nanotubes (SWCNTs) on a bulk scale has been an issue of considerable interest. Recently, it has been demonstrated that high quality SWCNTs can be continuously synthesized on large scale by using induction thermal plasma technology. In this process, the high energy density of the thermal plasma is employed to generate dense vapor-phase precursors for the synthesis of SWCNTs. With the current reactor system, a carbon soot product which contains approximately 40 wt% of SWCNTs can be continuously synthesized at the high production rate of ~100 g/h. In this article, our recent research efforts to achieve major advances in this technology are presented. Firstly, the processing parameters involved are examined systematically in order to evaluate their individual inÁuences on the SWCNT synthesis. Á Based on these results, the appropriate operating conditions of the induction thermal plasma process for an effective synthesis of SWCNTs are discussed. A characterization study has also been performed on the SWCNTs produced under the optimum processing conditions. Finally, a mathematical model of the process currently under development is described. The model will help us to better understand the synthesis of SWCNTs in the induction plasma process. KEYWORDSSingle-walled carbon nanotubes (SWCNTs), large-scale continuous synthesis, radio frequency (RF) induction thermal plasma, optimization, numerical modeling Nano ResearchOver the past decade, the superlative properties of single-walled carbon nanotubes (SWCNTs) [1] have attracted much attention for their use in a wide range of applications, including microelectronic [2], biomedical [3], polymer [4], energy [5], and environmental [6] devices. Consequently, the economical production of high quality SWCNTs on a large scale has become an issue of considerable interest. To date, there have been tremendous efforts to develop new synthesis methods leading to the economical production of SWCNTs and it has been shown that SWCNTs can be produced by many 801 Nano Res (2009) 2: 800 817 different ways, such as arc discharge, laser ablation, arc-jet plasmas, chemical vapor deposition (CVD), non-equilibrium plasmas, and combustion methods.Recently, it was demonstrated that high quality SWCNTs can be continuously synthesized, on a large scale, by the method of simultaneous direct evaporation of carbon black and metal/metaloxide catalyst mixtures, using induction thermal plasma technology [7]. In this process, the high energy density of the thermal plasma is employed to generate dense vapor-phase precursors for the synthesis of SWCNTs. The main advantages of this process are that the rate of input carbon is not limited by the rate of electrode erosion and that SWCNTs are synthesized in the free space without any substrates. Before undertaking optimization efforts, it was shown that a carbon soot product which contains approximately 40 wt% of SWCNTs can be continuously synthesized at production rates of over 100 g/h.The primary goal ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.