ch250 intermediate analysis – part 2 materials & nanotechnology dr raymond whitby c407
TRANSCRIPT
CH250 Intermediate Analysis – Part 2Materials & Nanotechnology
Dr Raymond WhitbyC407
Overview
1. Defining nano
2. Formation of nanocarbon
3. Viewing the nanoscale; direct analysis
4. Indirect analysis of the nanoscale
5. Adsorption experiment
2. Formation of nanocarbon
Carbon sp3 hybridisation
Carbon sp2 hybridisation
i.e. diamond
i.e. graphite
Difference in bonding geometry?
© Fessenden & Fessenden, Organic Chemistry, 5 th Edition
© Fessenden & Fessenden, Organic Chemistry, 5 th Edition© invsee.asu.edu
Benzene to graphite
Properties:Good electrical conductance in-planeGood lubricant in airGood thermal & acoustic propertiesPoor strength
Graphite to nanotube
© Youtube 2010
Graphite to nanotube
22 nmnmad
m and n are integer lattice pointsa is the lattice constant of graphite = 0.246nm
nm
n
2
3arctan
Diameter:
Chiral angle:
Ch = n a1 + m a2 = (n,m)
Graphite to nanotube
SWNTs:• Zig-zag nanotubes (n,0) → Metallic when n is divisible by three• Armchair nanotubes (n,n) → All are metallic.• Chiral nanotubes (n,m) → Metallic when n-m = 3q, where q is an integer.
© M. Terrones, et al. Top. Curr. Chem. 199, 189 (1999)
Properties:Good electrical conductanceGood thermal & acoustic propertiesHigh strengthPoor lubricant
Graphite bonding defects
5-membered ring
© Google images
Five 5-membered rings
Nanohorn
© theor.jinr.ru/disorder/nano.html
Twelve 5-membered rings
C60
© www.omicron.de© www.nanocenter.umd.edu
Metallofullerene peapods
© J.H. Warner, et al., Nano Lett., Vol. 8, No. 4, 2008
C60 C240 C540 C960
© McKay Nature 331, 328 (1988)
Giant fullerenes
Russian doll
© Florian Banhart, Max Planck Institute in Stuttgart, Germany
7-membered ring
© Hirsch, Angew Chem Ed, 2002, 41, 1853-9© theor.jinr.ru/disorder/nano.html
7-membered and 5-membered ring pairing
Carbon nanotube growth
© Y. Ando & M. Ohkohchi, J. Cryst. Growth, 60(1982), 147
Arc-discharge
Carbon nanotube growth
Chemical Vapour Deposition
© http://www.ifw-dresden.de© M. Terrones, et al., Top. Curr. Chem., 199, 189-234 (1999)
Nanocarbon in history
1985 and 1991 C60 and carbon nanotube
© H.W. Kroto, et al., (1985). Nature 318: 162–163© S. Iijima, Nature 354, 56 - 58 (1991)© S. Iijima, Nature 363, 603 - 605 (1993)
Nanocarbon in history
© Oberlin A, Endo M, Koyama T. Filamentous growth of carbon through benzene decomposition. J Cryst Growth 1976;32:335-49.
1976 unknown recognition
Nanocarbon in history
1952 completely missed recognition
© Radushkevich LV, Lukyanovich VM. O strukture ugleroda, obrazujucegosja pri termiceskom razlozenii okisi ugleroda na zeleznom kontakte. Zurn Fisic Chim 1952;26:88-95.
Nanocarbon in history
“The first mention of the possibility of forming carbon filaments from the thermal decomposition of gaseous hydrocarbon (methane) was reported in 1889 - i.e. literally two centuries ago! – in a patent that proposed the use of such filaments in the light bulbs that had just been presented by Edison at the Paris Universal Exposition the same year.”
1889 totally unknown recognition
© M. Monthioux, et al., CARBON 44 (2006) 1621
This refers to details contained within: Hughes TV, Chambers CR. US Patent 405480, 1889
Nanocarbon in history
17th Century Damascus Steel
© K. Sanderson (2006). "Sharpest cut from nanotube sword". Nature 444: 286
Nanocarbon in history
“The Permian-Triassic boundary (PTB) event, which occurred about 251.4 million years ago, is marked by the most severe mass extinction in the geologic record. Recent studies of some PTB sites indicate that the extinctions occurred very abruptly, consistent with a catastrophic, possibly extraterrestrial, cause. Fullerenes (C60 to C200) from sediments at the PTB contain trapped helium and argon with isotope ratios similar to the planetary component of carbonaceous chondrites. These data imply that an impact event (asteroidal or cometary) accompanied the extinction, as was the case for the Cretaceous-Tertiary extinction event about 65 million years ago. ”
© Luann Becker, et al., Science, 291, 1530 - 1533 (2001)
A really long time ago…
Questions on formation
1. If the smallest diameter single-walled carbon nanotube is 0.4nm (N. Wang, et al., Nature 408, 50-51 (2000)) for a zig-zag configuration, what is n and m?
2. What prevents this value from being smaller?
3. Is this carbon nanotube metallic?
4. What changes to a single sheet of graphite will cause enclosure to form a C60 molecule? Which ones are needed to form a spiral nanotube?
All material under copyright was scanned under a CLA licence