AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Aerosol Growth and Potential Applications of Carbon Nanostructures
Ji Hoon Kim, Kook Joo Moon, Ji Young Ahn, SOO H. KIM, Pusan National University
Abstract Number: 221 Working Group: Synthesis of Functional Materials using Flames, Plasmas and other Aerosol Methods
Abstract We demonstrate a one-step method for selectively growing aerosol carbon nanostructures with different shapes, including straight wires, coils, and sea urchins. The growth of aerosol carbon nanostructures in this approach was made on the N-Al bimetallic nanoparticles by the combination of spray pyrolysis and thermal chemical vapor deposition. We propose that the diameter of seeded bimetallic particles and the growing temperature of carbon nanostructures played a key role in growing aerosol carbon nanostructures. Coiled carbon nanotubes (CNTs) were formed on the entire surface of a seeded bimetallic nanoparticle with the average size of smaller than ~100 nm at medium temperature ranges of 500~650degC. Straight CNTs can be easily obtained with relatively high temperature ranges of 650~800degC, which result in melting the Al matrix sites in the seeded bimetallic nanoparticles so that the liquid-like Al matrix was then consumed by subsequent CNT precipitation. However, sea urchin-like CNTs are mostly grown on the seeded bimetallic particles with average size of larger than ~100 nm, in which Ni sites sufficiently isolated by Al sites are seeded to radially grow multiple CNTs with the average diameter of approximately 60 ± 13 nm under the medium reaction temperature ranges of 500~650degC. If the processing takes place at relatively high temperature ranges of 650~800degC, this makes Al molten and results in significant size reduction of available Ni sites by thermal expansion of non-catalytic Al matrix sites so that one can obtain sea urchin-like CNTs with the average diameter of approximately 10 ± 4 nm. Finally we introduce that the as-grown aerosol CNTs in this approach can be used directly with potential applications as polymer composite reinforcements and charge-/heat-transfer mediums.