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These are amorphousagglomerated sootnanoparticles collected on aninert SiC fiber placed in a flame
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Combustion products
Substrate
Catalyst chemistry and heatand mass transport
Nanofibrous carbon,
containing CNTs and CNFs
Nanofibrous carbon, containingCNTs and CNFs
Gas phase chemistry& transport Heat & mass transfer
Catalyst grain formation
Heat & mass transfer
Nanostructure formation
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The only model to include
catalysis, transport and
ambient conditions, suchas combustion.
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Zhang & Smith, J. Catal., 2005Bower et al., App. Phys. Lett., 2000
Bronikowski, Carbon, 2006
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CNT length versus time for CVDsynthesis at different
temperatures using Co as thecatalyst at a 5 Torr C2H2 partialpressure.
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!%##"('
''&""$
!"
"
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)$%&
)$'##
*!
+!
%##(
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!
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Naturally occurring superhydrophobic surfaces have microscalefeatures with nanoscale asperities.
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Naha, S., Sen, S. and Puri, I. K. Carbon 45, 2007.
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Flame Si disc(substrate)
Deposition zone due to flame
Air Fuel(Ethylene)
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Naha, S., Sen, S. and Puri, I. K. Carbon 45, 2007
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Cassie-Baxter State Water droplet sits partly on the solid
surface and partly on air trapped within
the asperities.
Contact angle results from contact ofwater with both air and the solidsubstrate.
Droplet tends to roll of easily.
Cannon, Andrew H. Wikipedia, the Free Encyclopedia. Web. 17 July
2010
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Disc center 45 mm from disc center
SEM images of nanopearls
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TEM images of nanopearls
Nanobead region Sooty region
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Nanobead region Sooty region
X-ray Photoelectric Spectroscopy (XPS) analysis using Mg source (anode)
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*Y. Zhou, B. Wang, X. Song, E. Li, G. Li, S. Zhao, H. Yan, Appl. Surf. Sci. 253 (2006) 2690-2694.
*&"+'.
%
"' *((.
"
#)*")+.$!
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0
5000
10000
15000
20000
25000
20030040050060070080090010001100
Binding Energy (eV)
Intensity
(arbitrary
units)
Nanobead Region Sooty Region
C1s
O1sO KVV
C KLL
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"!
#
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$"$$"$$"$$!
!)+#***%**,!)'('
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&
!"%')+#
"(&*#Ethylene
AirAir
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"#'+'&$&()
"#'++$
#'&!*&)
$
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!!"! *))"$%'"(
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!
h = 2 mm
= 34.15
h = 4 mm
=131.90
h = 6 mm
=126.80
h = 8 mm
=141.60
Coverage volumeincreases with height
No discernible carbonnanostructure deposit at2mm height and surfaceis hydrophilic
Spongy nanobeadclusters appear at heightsof 4 mm and above,leading to high contactangles
Mean nanoparticlesize at this stage is13 nm
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!
$$ !$"
#!
"
Stainless Steel Mesh (h = 10mm)
Stainless Steel Foil (h = 10mm)
Uncoated Silicon Wafer (h = 10mm)
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!
"#
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