Carbon nanotubes have a unique covalent structure that makes them over 200 times stronger than steel but only 1/1000th the thickness of a human hair, leading to significant interest from scientists in utilizing their properties; they can be manufactured through molecular engineering processes like chemical synthesis that arrange carbon atoms into nanotube structures on molecular templates; potential applications of carbon nanotubes include use in solar cells, sporting equipment, electronics, displays, and molecular engineering tools due to their mechanical and conductive properties.
2. Module Outcomes
Learn about different forms of carbon
Understand that properties of materials
are determined by covalent bonds
Explore the unique properties of
carbon nanotubes, and relate these to
current and potential applications.
3. Did You Know?
Carbon nanotubes, composed of
interlocking carbon atoms, are 1000x
thinner than an average human hair
but can be 200x stronger than steel.
Image: Schwarzm, Wikipedia
4. Which Of These Object Are Made
From Carbon?
Water Diamond Graphite Nanotube Coal
Images: L To R: snapr@flickr, swamibu@flickr, orangeacid@flickr, Mstroeck @ Wikipedia,
5. Activity 1
Perform the Researching Carbon Activity
to learn more about the following
allotropes (different forms) of carbon:
coal, graphite, diamond, buckyballs, carbon nanotubes.
7. Did You Know?
Allotropes of carbon have different covalent bonding arrangements.
diamond graphite buckyball nanotube
Carbon atoms form covalent bonds by sharing outer shell electrons
with each other
Diamond, graphite, buckyballs and carbon nanotubes all have
different covalent arrangements of carbon atoms
The differing covalent arrangements of carbon atoms lead to the
different properties of carbon allotropes.
Image: Mstroeck @ Wikipedia
8. Covalent Bonding Sharing Electrons
proton A covalent bond is a form of chemical
neutron
electron
bonding that is characterised by the sharing of
pairs of electrons between atoms
Valence electrons are the electrons in the
outer shell or energy level of an atom that form
covalent bonds
A carbon atom has 6 electrons, 4 of which are
Valence electrons
Therefore, carbon atoms can form up to 4
6 protons + 6 Covalent Bonds
neutrons
Image: Google, 息 NDT Education Resource Centre
9. Covalent Bonds In Diamond
Diamond is formed by a 3D
box-like network of carbon
atoms
The continuous nature of the
covalent arrangements forms
a giant molecule
Electrons are fixed.
carbon covalent
atoms bonds
Image: Wikipedia
10. Covalent Bonds In Graphite
Graphite is formed by
hexagonally-arranged carbon
molecules forming 2D layers
of sheets
Electrons are free to move
between each carbon sheet.
Image: Wikipedia
11. Covalent Bonds In Buckyballs
Carbon atoms in buckyballs
are arranged in a soccer ball
shape
C60 Buckyballs have 20
regular hexagon faces and 12
regular pentagon faces
- these faces come together
at 60 carbon atom vertices
Electrons are localised
internally due to the
curvature of the structure.
Image: Mstroeck @ Wikipedia
12. A Bit More About Buckyballs
Buckyballs are also called
fullerenes (after architect
Richard Buckminster Fuller)
Buckyballs were discovered
in 1985 by Robert Curl,
Harold Kroto and Richard
Smalley
- these scientists won the
1996 Nobel Prize in
Chemistry for discovering
Buckyballs in crystalline form this new allotrope of carbon.
Image: Wikipedia
13. Covalent Bonds In Carbon Nanotubes
Carbon nanotubes are formed by
a layer of hexagonally-arranged
carbon atoms rolled into a cylinder
- usually have half buckyballs on
one or both ends
Electrons are localised internally,
and some can move along the
length of the tube by ballistic
transport
Carbon nanotube diameter ~ 1nm
Carbon nanotube length can be a
million times greater than its width
Nanotubes can be
- single-walled (d = 1-2 nm), or
- multi-walled (d = 5-80 nm).
Image: Wikipedia
14. Properties of Carbon Allotropes
Allotrope Hardness Tensile Conducts Conducts
strength heat electricity
Coal + + + no
Graphite ++ ++ +++++ +++++
Not
Diamond +++++ known +++ no
Buckyballs +++++ ++++ + +
Carbon
Nanotubes ++++++ +++++ +++++ ++++++
15. Properties of Carbon Allotropes
Allotrope hardness tensile conducts conducts
strength heat electricity
Coal + + + no
Graphite ++ ++ +++++ +++++
Not
Diamond +++++ known +++ no
Buckyballs +++++ ++++ + +
Carbon
Nanotubes ++++++ +++++ +++++ ++++++
16. Unique Properties Of Carbon Nanotubes
200x stronger than steel of the same diameter
The first synthetic material to have greater strength than
spider silk
Excellent conductors of electricity and heat
Have huge potential for product development.
Image: wafonso@flickr, digidreamgraphix@flickr
17. Activity 2
Perform the Allotropes of Carbon
Activity to further explore the molecular
structure and properties of carbon
allotropes.
18. Carbon Nanotubes
Given their unique properties, what
can carbon nanotubes be used for?
Image: Schwarzm, Wikipedia
19. Nanotubes In Efficient Solar Cells
Scientists have developed
the blackest black colour
using carbon nanotubes
The carbon nanotubes are
arranged like blades of
grass in a lawn
- they absorb nearly all light
Use of carbon nanotubes in
solar cells could vastly
improve their efficiency.
Image: mulad@flickr.com
20. Nanotubes In Sporting Equipment
Badminton racquet manufacturer
Yonex incorporates carbon
nanotubes into their cup stack
carbon nanotubes racquets
(www.yonex.com)
American baseball bat
manufacturer Easton Sports has
formed an alliance with a
nanotechnology company Zyvex
to develop baseball bats
incorporating carbon nanotubes
Tennis racquets also incorporate
carbon nanotubes
(www.babolat.com).
Image: stuseeger@flickr.com
21. Nanotubes In Miniaturised Electronics
Branching and switching
of signals at electronic
junctions is similar to
what happens in nerves
A carbon nanotube
neural tree can be
trained to perform
complex switching and
computing functions
Could be used to
detect/respond to
electronic, acoustic,
chemical or thermal
signals.
Image: hulio@flickr.com
22. Nanotubes In AV Technology
Carbon nanotubes
are being used to
develop flat screen
televisions with
higher resolution than
the human eye can
detect
Your next TV screen
could be thin, ultra-
light and foldable
Image: jamescridland@flickr.com
23. Graphene Sheets
A new form of carbon with many potential uses.
Professor Gordon Wallace and his team at the
University of Wollongong have been studying
this new form of carbon just one atom thick
The very unusual electronic properties of
graphene sheets means they could be used in
solar cells or new battery technology, he says
Because of the biological affinity of carbon,
they might also be useful as electrodes for a
range of medical bionic devices such as
cochlear implants
Graphene sheets could also be used to create
transparent electrodes and coatings that
prevent the build up of static electricity.
Image: 息 Dorling Kindersley
24. How Are Nanosized Carbon
Structures Made?
Image: erikcharlton@flickr
25. Manufacturing Carbon Nanotubes
Molecular Engineering
Carbon nanotubes can be made using molecular
engineering
Molecular templates are created
- under the right chemical conditions carbon atoms
arrange themselves into nanotubes on the template
This process is also known as chemical synthesis or
self-assembly, and is an example of the bottom-up
approach to molecular engineering.
26. Molecular Engineering
2 Approaches
Bottom-up approach: structures are built
atom by atom
- can use self-assembly or sophisticated
tools (eg scanning tunnelling microscope,
atomic force microscope) which can pick
up, slide or drag atoms or molecules around
to build simple nanostructures
Top-down approach: traditional
engineering techniques such as machining
and etching are used at very small scales
- products tend to be refinements of existing
products, such as electronic chips with
more and more components crammed onto
them.
Image: kikisdad@flickr.com
27. Top Down Vs Bottom Up
Nanotechnology
Watch the video found at the following
website to improve your understanding of
the difference between top-down and
bottom-up approaches to manufacturing:
www.nanohub.org/resources/96/
28. Bottom Up Approach:
Using Nanotube Tweezers
Molecular devices can be
constructed using nanotube
tweezers
The tips of the nanotube
tweezers can be opened and
closed by switching on and off a
voltage between the two
Carbon Nanotube probes
Nanotube tweezers are tools for
use in the bottom-up approach.
Image: 息 JEOL
29. Activity 3 Research Questions
Are there any safety issues associated with
the use of carbon nanotubes?
Peform the Safety Issues of
Carbon Nanotubes activity
Images: L To R: snapr@flickr, swamibu@flickr, orangeacid@flickr, Mstroeck @ Wikipedia,
30. Summary
Covalent bonds form when atoms share electrons
Carbon exists in many forms due to its ability to
stably form different covalent bonding arrangements
The bulk properties of materials are determined by
the covalent bonding arrangement of atoms
Carbon nanotubes have very different properties
compared to the other carbon allotropes
- these unique properties offer huge potential in
product development.
31. Revision
1. What are carbon nanotubes and why
are scientists so interested in them?
2. How are carbon nanotubes made?
#4: Image from http://en.wikipedia.org/wiki/Image:Kohlenstoffnanoroehre_Animation.gif, GNU free documentation license by http://de.wikipedia.org/wiki/Benutzer:Schwarzm
#5: Water image from flickr http://www.flickr.com/photos/snapr/484776493/(creative commons license) Diamond image thanks to http://www.flickr.com/photos/swamibu/1182138940/ (creative commons license) Pencil image thanks to http://www.flickr.com/photos/orangeacid/204163563/ (creative commons license) Nanotube image from http://en.wikipedia.org/wiki/Image:Eight_Allotropes_of_Carbon.png, GNU free documentation license, courtesy of Michael Strock http://en.wikipedia.org/wiki/User:Mstroeck Coal image from wikipedia: This image is a work of the "Minerals in Your World" project, a cooperative effort between the United States Geological Survey and the Mineral Information Institute. The images were featured in the "Minerals and Materials Photo Gallery" on the website of the U.S House Subcommittee on Energy and Natural Resources. As a work of the U.S. federal government, the image is in the public domain .
#8: Nanotube image from http://en.wikipedia.org/wiki/Image:Eight_Allotropes_of_Carbon.png, GNU free documentation license, courtesy of Michael Strock http://en.wikipedia.org/wiki/User:Mstroeck
#10: Nanotube image from http://en.wikipedia.org/wiki/Image:Eight_Allotropes_of_Carbon.png, GNU free documentation license, courtesy of Michael Strock http://en.wikipedia.org/wiki/User:Mstroeck
#11: Nanotube image from http://en.wikipedia.org/wiki/Image:Eight_Allotropes_of_Carbon.png, GNU free documentation license, courtesy of Michael Strock http://en.wikipedia.org/wiki/User:Mstroeck
#12: Nanotube image from http://en.wikipedia.org/wiki/Image:Eight_Allotropes_of_Carbon.png, GNU free documentation license, courtesy of Michael Strock http://en.wikipedia.org/wiki/User:Mstroeck
#13: Image from http://en.wikipedia.org/wiki/Image:C60-Fulleren-kristallin.JPG, GNU free documentation license, thanks to http://de.wikipedia.org/wiki/Benutzer:Moebius1
#14: Nanotube image from http://en.wikipedia.org/wiki/Image:Eight_Allotropes_of_Carbon.png, GNU free documentation license, courtesy of Michael Strock http://en.wikipedia.org/wiki/User:Mstroeck
#15: NB buckyballs can be effective conductors if doped with other elements.
#16: NB buckyballs can be effective conductors if doped with other elements.
#17: Images thanks to http://www.flickr.com/photos/wafonso/161384471/ and http://www.flickr.com/photos/digidreamgrafix/2847684034/ (creative commons license)
#19: Image from http://en.wikipedia.org/wiki/Image:Kohlenstoffnanoroehre_Animation.gif, GNU free documentation license by http://de.wikipedia.org/wiki/Benutzer:Schwarzm
#20: Story found at www.abc.net.au/science/articles/2008/01/16/2139711.html Image thanks to http://www.flickr.com/photos/mulad/2902904747/ (creative commons license)
#21: Image thanks to http://www.flickr.com/photos/stuseeger/2419642327/ (creative commons license)
#22: Information from Source Ames Research Center NASA Image thanks to http://www.flickr.com/photos/hulio/440232106/ (creative commons license)
#23: Information Sources: http://www.trnmag.com/Stories/032801/Nanotubes_paint_clear_picture_032801.html Image thanks to http://www.flickr.com/photos/jamescridland/424166415/ (creative commons license)
#25: Image thanks to http://www.flickr.com/photos/erikcharlton/2303709058/ (creative commons license)
#27: http://www.nanotechnology.com/docs/wtd015798.pdf Image thanks to http://www.flickr.com/photos/kikisdad/33679340/ (creative commons license)
#28: LSPM Team, EPICS (2005), "Nanomanufacturing: Top-Down and Bottom-Up," http://www.nanohub.org/resources/96/.
#29: Info and image from http://www.jeol.se/JEOL%20News/news37E/htm/70/index.htm
#31: Image from http://en.wikipedia.org/wiki/Image:Kohlenstoffnanoroehre_Animation.gif, GNU free documentation license by http://de.wikipedia.org/wiki/Benutzer:Schwarzm