Transcript Optimization of the purification procedure for single

By: Steven Wehmeyer
Supervisor: Dr. Ajay Malshe
Summer REU
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Mechanical Engineering Department
Colleagues in MMRL
Financial Support from ONR
Dr. Malshe, Dr. Demytro, Dr. Benamara,
Ranjith John.
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Electronics
◦ Transistors
 Cell phones
 Computers
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Biomedical
◦ Cancer treatment
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Ballistic
◦ Body armor
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Amazing properties
◦ Thermal conductivity 6600 W/m-K
 2-3 times higher than diamond
◦ Elastic Modulus 1-5 TPa
 3-4 times higher than diamond
 Steel ~ .2 TPa
◦ Electrical conductivity 10^4 S/cm
 Gold 4.5x10^5 S/cm
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Need to be pure to take full advantage of
properties
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High Pressure catalytic
decomposition of carbon
monoxide (HIPCO)
Arc discharge
Laser ablation
CVD
Synthesis (HIPCO)
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Raw material
◦ High Pressure catalytic decomposition of carbon
monoxide (HIPCO) from Unidym
◦ Elicarb from Swan Chemical Inc.
 Oxidize
 Heat
 Acid reflux
 Hydrochloric Acid (HCl)
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Purified SWNT
Characterize
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Time= 3-4 days
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◦ Transmission Electron Microscope
◦ Thermogravimetric Analysis
◦ Raman Spectroscopy
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Combine oxidation and acid reflux3
◦ H2O2 for oxidizing and HCl for acid reflux
 Different concentrations
 Fenton’s reagent
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Combine with carbon nanotubes and heat
mixture (90-110°C) for eight hours to
accelerate processes
Vacuum Filtration
Heat to remove moisture
Characterize
◦ TEM, TGA, Raman Spectroscopy
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Time= 1 day
HIPCO
Run
Order
1
2
3
4
5
6
7
8
9
10
11
12
Raman
A:Reaction
TGA
B:Concentration
Spectroscopy
Temp
Response
Response
90
6M
80
1M
110
3M
100
3M
110
6M
80
6M
80
3M
90
3M
90
1M
100
1M
110
1M
100
6M
Iron Dissolution
Vacuum Filtration
P7
P8
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TGA
◦ Analysis will occur Tuesday through Friday at UALR
◦ Looking for % wt purity. Burns sample and iron is
left. Percent purity can then be obtained.
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Raman Spectroscopy
◦ Light scattering Technique. Uses laser to excite
phonons and shift their energy level. These Raman
shifts can be used to determine information about
the carbon nanotubes. Looking for diameter and
length of nanotubes.
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Carbon nanotubes were purified as indicated
by iron dissolution
◦ Percent pure not known yet
◦ TEM images have shown that no big impurities exist
in samples
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Process works
◦ Further work may be needed to optimize further
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Further results and conclusions will be known
after analyzing samples at UALR
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2.
3.
Benamara, Mourad. TEM images.
Unalan, Husnu Emrah. “Single walled carbon nanotube thin
films: Properties and applications” Diss. Rutgers The State
University of New Jersey, New Brunswick, 2006.
Dissertations & Theses: Full Text. ProQuest. 28 May. 2009
Wang, Yuhuang, Hongwei Shan, Robert H. Hauge, Matteo
Pasquali, and Richard E. Smalley, “A highly selective, one-pot
purification method for single-walled carbon nanotubes”
The Journal of Physical Chemistry B 111.6 (24 January 2007):
1249-1252