Carbon nanofibers
Carbon
nanofibers are a type of nanoscale carbon fiber that is a one-dimensional
carbon component between carbon nanotubes and carbon fibers. They can be
classified as hollow carbon nanofibers and solid carbon nanofibers according to
their structural properties. Its diameter is usually in the range of 10 to 500 nm
and its length is from 0.5 to 200 mm. It has a higher degree of crystal
orientation and is preferred for electrical and thermal conductivity. Not only
does it have the same or lower density, high modulus, high strength, high
conductivity, and thermal stability, but also has advantages such as a small
number of defects, a large aspect ratio, a large surface, and a compact
structure.
History of carbon nanofibers
One
of the first technical records concerning carbon nanofibers was probably
patented in 1889 filamentous carbon synthesis by Hughes and Chambers. They use
a methane/hydrogen gaseous mixture and increase the carbon filament through gas
pyrolysis and subsequent carbon accumulation and filament growth. The actual
realization of these fibers came much later when their structure could be
analyzed by electronic microscopy. The first electronic microscopy examining
carbon nanofibers that were performed in the early 1950s by Soviet scientists
Raduskevich and Lukyanovich. In 1991, Japanese researcher Sumio Ijima
synthesized hollow carbon molecules to determine their crystal structure. At
that time, these molecules were called "carbon nanotubes". VGCNF is produced
through basically the same manufacturing process as VGCF, only the diameter is
usually less than 200 nm. Some global companies are actively involved in the
commercial-scale production of carbon nanofibers and new engineering
applications are being intensively developed for these materials.
Properties of carbon nanofibers
1.
Carbon nanofibers have a high level of chemical bonding flexibility.
2.
It has a number of allotropes including diamond, graphite, and fullerenes.
3.
This underscores the versatility of CNFs, which is notable for their thermal,
electrical, and electromagnetic protection, and increase in mechanical properties.
4.
Since carbon is readily available at a low cost, CNFs are a popular addition to
composite materials.
5.
CNFs exist on very small, nanometer scales.
6.
Carbon nanofibers (CNFs) are clearly used as anode materials for the production
of numerous interstitial sites, they show the great performance of sodium and
lithium storage.
7.
Carbon nanofibers (CNF) are produced catalytically in the CVD process.
8.
It has a diameter ranging between 150–300 nm.
0 Comments