Authors: A.V. Vasenkov, V.V. Kolobov, D. Carnahan
Affilation: CFD Research Corporation, United States
Pages: 159 - 162
Keywords: low-temperature synthesis, catalytic exothermic reactions, inductive heating, carbon-nanotubes, multi-scale modeling, chemical vapor deposition, flat panel displays, sensors, computer chips
Chemical Vapor Deposition (CVD) of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) is a catalytically controlled synthesis requiring catalyst temperatures in excess of 700°C. The CVD synthesis is typically accompanied by significant substrate heating which is not necessary for the actual synthesis process and often damages the surface of temperature-sensitive material or causes device integration problems. Our approach is to develop technology for selective heating catalytic nanoparticles by (i) induction heating resulting from the radio-frequency (RF) electromagnetic fields and/or (ii) heating from enhanced exothermic catalytic reactions. Based on experimental and computational data, we have designed a novel reactor for the production of CNTs/CNFs at temperature below 500°C. Vertical alignment of free-standing CNTs/CNFs in this reactor is achieved using inductively coupled plasma. This eliminates a requirement to have a conducting substrate. Also, our reactor is equipped with RF source for induction heating that operates at frequency that ranges from 10 MHz to 20 GHz depending on the particle size. Results for selective heating catalytic nanoparticles during the growth of carbon nanotubes are discussed.