optimization of the purification procedure for single-walled carbon nanotubes
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Optimization of the purification procedure for single-walled carbon nanotubes. By: Steven Wehmeyer Supervisor: Dr. Ajay Malshe Summer REU. Acknowledgements. Mechanical Engineering Department Colleagues in MMRL Financial Support from ONR - PowerPoint PPT PresentationTRANSCRIPT
Optimization of the purification procedure for single-walled
carbon nanotubes
By: Steven WehmeyerSupervisor: Dr. Ajay Malshe
Summer REU
Mechanical Engineering Department Colleagues in MMRL Financial Support from ONR Dr. Malshe, Dr. Demytro, Dr. Benamara,
Ranjith John.
Acknowledgements
Electronics◦ Transistors
Cell phones Computers
Biomedical◦ Cancer treatment
Ballistic◦ Body armor
Applications
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
Need to be pure to take full advantage of properties
Importance of Carbon Nanotubes
High Pressure catalytic decomposition of carbon monoxide (HIPCO)
Arc discharge Laser ablation CVD
Synthesis
Synthesis (HIPCO)
Raw material◦ High Pressure catalytic decomposition of carbon monoxide
(HIPCO) from Unidym◦ Elicarb from Swan Chemical Inc.
Oxidize Heat
Acid reflux Hydrochloric Acid (HCl)
Purified SWNT Characterize
◦ Transmission Electron Microscope◦ Thermogravimetric Analysis◦ Raman Spectroscopy
Time= 3-4 days
General purification
Combine oxidation and acid reflux3
◦ H2O2 for oxidizing and HCl for acid reflux Different concentrations Fenton’s reagent
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 Time= 1 day
Method of Purification Used
Design of ExperimentHIPCO Run
OrderA:Reaction
TempB:Concentratio
n
TGA Respons
e
Raman Spectroscopy
Response 1 90 6M 2 80 1M 3 110 3M 4 100 3M 5 110 6M 6 80 6M 7 80 3M 8 90 3M 9 90 1M 10 100 1M 11 110 1M 12 100 6M
Results
Vacuum FiltrationIron Dissolution
Characterization - TEM
P7 P8
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. 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.
Characterization
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 Process works
◦ Further work may be needed to optimize further Further results and conclusions will be
known after analyzing samples at UALR
Conclusions
1. Benamara, Mourad. TEM images.2. 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
3. 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
References