Synthesis of carbon nanocoils by microwave CVD

Abstract

The carbon nanocoil is an interesting kind of nanomaterial, which is expected to have various novel applications in microelectronics, microelectromechanical systems (MEMS) and bioMEMS due to its nanosize coil morphology. Carbon nanocoils were synthesized by catalytic pyrolysis of acetylene over 2.2–3.0 µm Ni particles at 600°C in a microwave chemical vapour deposition (CVD) system. Microwave CVD derived nanocoils are rather uniform with an average coil diameter of 110–170 nm, fibre diameter of 80–120 nm and pitch of around 130–200 nm. The effects of reaction temperature, the size of Ni catalyst and the flow rate of acetylene were examined. Additionally, the growth mechanism of carbon nanocoils was studied. It was found that two individual carbon nanocoils extrude from the same Ni particle in the same direction as straight fibres at the beginning and then bend to grow into nanocoils in opposite directions.

Advances in Ablative Composites of Carbon Based Materials: A Review

“…The fracture properties and microstructure of ZrB 2 –C/C composite as a result of reinforcement with multiwalled carbon nanotubes has been studied, wherein the fracture toughness of the composite improved significantly, which was attributed to moderate fiber–matrix interfacial bonding via fiber pull out bridging and crack deflection at interface sites. To improve mechanical properties of ultrahigh-temperature ceramics, application of graphite nanoflakes, , carbon nanofibers, and carbon nanocoils is undertaken.…”

A plausible mechanism for the evolution of helical forms in nanostructure growth

“…Consequently, ⍀ ͑⌬H͒ can be negative if the ambient conditions promote a nonwettability behavior, i.e., through catalyst particles that have a greater tendency for cohesion than adhesion onto the growing NT/ NF. Increased ambient entropy, say through agitation, in ultrasonic 5 or microwave 25 CVD, or use of sublimating compounds, 31 can have a similar effect. One can confirm specific cases where the above situations are plausible through comparison with experiment.…”

Carbon nanocoils for multi-functional energy applications

“…[9][10][11][12][13][14][15][16][17] For the growth of carbon nanocoils, various supported catalysts, hydrocarbons, and processing conditions have been employed yielding a range of products such as amorphous coiled carbon fibers/tubules and nanotubes. [18][19][20][21][22][23][24] The present work describes a modified synthesis of MWNCs in bulk quantities by the catalytic decomposition of acetylene over hydrogen decrepitated alloy hydride coated carbon fabric.…”