Carbon nanotubes synthesis using diffusion and premixed flame methods: a review

Abstract

In recent years, flame synthesis has absorbed a great deal of attention as a combustion method for the production of metal oxide nanoparticles, carbon nanotubes, and other related carbon nanostructures, over the existing conventional methods. Flame synthesis is an energyefficient, scalable, cost-effective, rapid and continuous process, where flame provides the necessary chemical species for the nucleation of carbon structures (feed stock or precursor) and the energy for the production of carbon nanostructures. The production yield can be optimized by altering various parameters such as fuel profile, equivalence ratio, catalyst chemistry and structure, burner configuration and residence time. In the present report, diffusion and premixed flame synthesis methods are reviewed to develop a better understanding of factors affecting the morphology, positioning, purity, uniformity and scalability for the development of carbon nanotubes along with their correlated carbonaceous derivative nanostructures.

Recent Development of Carbon Nanotube Transparent Conductive Films

“…Starting with the raw materials, CNTs can be synthesized via a variety of methods, including electric arc discharge, laser ablation, vaporization induced by a solar beam, catalytic chemical vapor deposition (CVD), plasma-enhanced CVD, laser-assisted CVD, and so on. − Although some of these methods are highly energy-consuming, large-scale industrial manufacturing of CNTs with improved properties is realizable based on the facts that the production output reached ∼5 kiloton annually in 2011 and the estimated production output in 2022 will be >20 kiloton. , To obtain either metallic or semiconducting enriched CNT, a number of selective synthesis methods concerning controlling some vital factors, such as catalyst particles, − carbon source, − growth temperature, − substrates, − and other cotreatments, during the synthesis have been designed. In addition, the same diversity of nanotubes can also be obtained by post-growth purification, such as density-gradient ultracentrifugation, − gel exclusion of surfactant-wrapped CNT, ion-exchange chromatography of DNA-wrapped CNT, UV irradiation, electrical breakdown, − selective gas-phase plasma etching, and alternating current dielectrophoresis. , Recently, a novel separation method was developed to achieve high-purity single-chirality SWCNTs.…”

Carbon Nanotubes: Current Perspectives on Diverse Applications in Targeted Drug Delivery and Therapies

“…These are the less used processes or methods for the synthesis of CNTs, which include the helium arc discharge method, electrolysis [30] and flame synthesis [31]. George Washington University researchers found a new pathway in 2015 for synthesizing MWCNTs via electrolysis of molten carbonates, and the mechanism is similar to that of CVD.…”

Carbon-Based Nanofluids and Their Advances towards Heat Transfer Applications—A Review

“…There are three main synthesis methods for producing CNTs, which are the arc discharge, laser ablation, and CVD [ 109 , 110 , 111 ]. Other approaches, such as diffusion and premised flame method, can be used for CNTs fabrication but are less frequently utilized [ 112 ]. All three primary production methods depend on the carbon feedstock, either as a solid phased carbon source (arc discharge and laser ablation) or carbonaceous gases (CVD method).…”