Acetylene‐Enhanced Growth of Carbon Nanotubes on Ceramic Microparticles for Multi‐Scale Hybrid Structures

Abstract

A mixture of acetylene and xylene is used as the carbon source to directly synthesize carbon nanotube (CNT)/alumina (Al 2 O 3 ) microsphere hybrid structures by CVD. The hybrid structures are modulated by varying the acetylene ratio and reactor temperature. The addition of acetylene can significantly improve the CNT growth rate on Al 2 O 3 at temperatures lower than 600 8C. A tenfold improvement in CNT growth rate is obtained at 550 8C when only 2 vol.-% acetylene is added. Meanwhile, acetylene favors the formation of bundles containing high-density CNTs. The increase in the temperature promotes the formation of CNTs with large diameters and low number density. Mass spectrometry (MS) is used to investigate the decomposition of a mixture of acetylene/xylene at temperatures ranging from 450 to 700 8C, under the experimental conditions used. Acetylene decomposes with an increasing rate with temperature from 450 8C, however notable decomposition of xylene is not detected below 700 8C, which corresponds to the formation of the CNTs of varied diameters. This study demonstrates the possibility of large-scale production of desired nano/micrometer multifunctional CNT/Al 2 O 3 hybrid fillers using a gas/liquid mixed carbon source.

One-Dimensional Carbon Nanostructures: Low-Temperature Chemical Vapor Synthesis and Applications

“…Although they do not contribute to the construction of CNs directly, their roles are somehow critical. For example, in some experimental settings they work as the carrier gas to bring the catalyst into the reaction chamber [54]. Moreover, except few special processes which require ultra-high vacuum (UHV) condition [52,62], most of the low-temperature CVD growth can progress in a broad pressure range (even in atmospheric pressure [64,67,71]).…”

Multifunctional polymer composites reinforced by carbon nanotubes–Alumina hybrids with urchin-like structure

“…[20,33] It was well known that CNT growth and self-organization on the microparticles depend greatly on the substrate crystallization structure and morphologies, as well as CVD conditions used. [28,31,34] In most cases reported, the CNTs bundles (agglomerated) have been found, especially for long CNTs. [29,35], which may generate structural defects in composites.…”

Application of Carbon Nanotubes Directly Grown on Aluminum Foils as Electric Double Layer Capacitor Electrodes

“…[27] Acetylene seems to be the best choice because it is thermodynamically the least stable hydrocarbon at low temperatures (up to 1000 K). [28,29] Aluminum oxide is commonly used as a support preventing the catalyst particles (usually Fe, Co, Ni, or their combinations) from Oswald ripening and agglomeration. [26,30] Here, we report a scalable method for the atmospheric pressure (AP)CCVD of CNTs on Al foils to make hybrid electrodes for EDLCs.…”