1. Nano technology John Summerscales University of Plymouth
School of Marine Science and Engineering
University of Plymouth

2. Orders of magnitude x
10-x
10+x 3
milli- (m)
kilo- (k)* 6
micro- (μ)
mega- (M) 9
nano- (n)
giga- (G) 12
pico- (p)
tera- (T) 15
femto- (f)
peta- (P) 18
atto- (a)
exa- (E)
* note that capital K is used, in computing, to represent 210 or 1024, while k is 1000.

3. Sub-metre scales 0.0532 nm = radius of 1s electron orbital
0.139 nm = C-C bond length in benzene
0.517 nm = lattice constant of diamond
atto-
femto-
pico-
nano-
micro-
milli-
metre

4. Nanostructures
surface structures with feature sizes from nanometres to micrometres
white light optics limited to ~1μm
use electron-beam or x-ray lithography and chemical etching/deposition
image = calcium fluoride analog of a photoresist from

5. Carbon Elemental carbon may be or one of two crystalline forms:
amorphous
or one of two crystalline forms:
diamond (cubic crystal sp3 structure)
graphite (contiguous sp2 sheets)
graphene (single atom thickness layers of graphite)
or at nanoscale can combine to form
spheres (buckminsterfullerenes or “bucky balls”)
and/or nanotubes

6. Graphene single atom thickness layers of graphite
thinnest material known
one of the strongest materials known
conducts electricity as efficiently as copper
conducts heat better than all other materials
almost completely transparent
so dense that even the helium atom cannot pass through

7. Graphene * in-plane bond length = 0.142 nm (vs 0.133 for C=C bond)
Property
Units
Magnitude
Comment
Source
Thickness nm
0.33*
[1]
Areal density
μg/m2
770
~1g / football field
[2]
Tensile modulus
GPa
500
Tensile strength
1000
~333x virgin CF
Transparency
% absorption
2.3
* in-plane bond length = nm (vs for C=C bond)

8. Penta-graphene announced Feb. 2015 stable to 1000K (727ºC)
semiconductor
auxetic
image from

9. Nanotubes Carbon-60 bucky-balls (1985)
graphitic sheets seamlessly wrapped to form cylinders (Sumio Iijima, 1991)
few nano-meters in diameter, yet (presently) up to a milli-meter long
Image from

10. Nanotubes SWNT = single-wall nano-tube MWNT = multi-wall nano-tube
benzene rings may be
zigzag: aligned with tube axis
armchair: normal to tube axis
chiral: angled to tube axis
Image from via
MWNT = multi-wall nano-tube
concentric graphene cylinders

11. Nanotube production
arc discharge through high purity graphite electrodes in low pressure helium (He)
laser vapourisation of a graphite target sealed in argon (Ar) at 1200°C.
electrolysis of graphite electrodes immersed in molten lithium chloride under an Ar.
CVD of hydrocarbons in the presence of metals catalysts.
concentrating solar energy onto carbon-metal target in an inert atmosphere.

12. Nanotube purification
oxidation at 700°C (<5% yield)
filtering colloidal suspensions
ultrasonically assisted microfiltration
microwave heating together with acid treatments to remove residual metals.

13. Nanotube properties SWNT (Yu et al) MWNT (Demczyk et al)
E = (mean = 1002) GPa
σ´ = (mean = 30) GPa
MWNT (Demczyk et al)
σ´ = GPa
σ´ = 150 GPa

14. 2D group IV element monolayers
Central column of periodic table
(covalent bonding atoms)
graphene (2D carbon)
silicene (2D silicon) unstable
germanene (2D germanium) rare
stanene (2D tin)
plumbene (2D lead) not attempted ?

15. Curran®: carrot fibres
CelluComp (Scotland)
nano-fibres extracted from vegetables
carrot nano-fibres claimed to have:
modulus of 130 GPa
strengths up to 5 GPa
failure strains of over 5%
potential for turnips, swede and parsnips
first product is "Just Cast" fly-fishing rod.

16. Exfoliated clays layered inorganic compounds which can be delaminated
most common smectite clay used for nanocomposites is montmorillonite
plate structure with a thickness of one nanometre or less and an aspect ratio of 1000:1 (hence a plate edge of ~ 1 μm)

17. Exfoliated clays Relatively low levels of clay loading are claimed to:
improve modulus
improve flexural strength
increase heat distortion temperature
improve gas barrier properties
without compromising impact and clarity

18. nano-technology fabrication .. and .. probes
chemical vapour deposition
electron beam or UV lithography
pulsed laser deposition
atomic force microscope
scanning tunnelling microscope
superconducting quantum interference device (SQUID)

19. Atomic force microscope
measures force and deflection at nanoscale
image from

20. Scanning tunnelling microscope
scans an electrical probe over a surface to detect a weak electric current flowing between the tip and the surface
image from

21. Superconducting QUantum Interference Device (SQUID)
measures extremely weak magnetic signals
e.g. subtle changes in the electromagnetic energy field of the human body.

22. MEMS: micro electro mechanical systems
Microelectronics and micromachining on a silicon substrate
MEMS electrically-driven motors smaller than the diameter of a human hair
Image from

23. Controlled crystal growth
Brigid Heywood
Crystal Science Group at Keele
controlling nucleation and growth of inorganic materials to make crystalline materials
protein templates

24. Acknowledgements
Various websites from which images have been extracted

25. To contact me: Dr John Summerscales ACMC/SMSE, Reynolds Room 008
University of Plymouth
Devon PL4 8AA