Www.panstanford.com Chapters 1-4 Presentation Slides for Science at the Nanoscale: An Introductory...
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www.panstanford.com Chapters 1-4 Presentation Slides for Science at the Nanoscale: An Introductory Textbook by Chin Wee Shong, Sow Chorng Haur & Andrew T. S. Wee National University of Singapore ISBN: 9789814241038 Hardcover August 2009 228 pages More information at www.panstanford.com/nanotextb ook
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Transcript of Www.panstanford.com Chapters 1-4 Presentation Slides for Science at the Nanoscale: An Introductory...
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Chapters 1-4 Presentation Slides forScience at the Nanoscale: An Introductory Textbookby Chin Wee Shong, Sow Chorng Haur & Andrew T. S. WeeNational University of Singapore
ISBN: 9789814241038HardcoverAugust 2009228 pages
More information at www.panstanford.com/nanotextbook
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Chapter 1
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Name Abbrev. Sci. Unit Representative objects with this size scale
metre m 100 Height of a 7-year-old child.
deci- dm 10−1 Size of our palm.
centi- cm 10−2 Length of a bee.
milli- mm 10−3 Thickness of ordinary paperclip.
micro- μm 10−6 Size of typical dust particles.
nano- nm 10−9 The diametre of a C60 molecule is about 1 nm.
pico- pm 10−12 Radius of a Hydrogen Atom is about 23 pm.
femto- fm 10−15 Size of a typical nucleus of an atom is 10 fm.
atto- am 10−18 Estimated size of an electron.
Just how small is nano?
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Scale of Things
ZnO Nanorods Diameter ~ 100 nm
Abalone Shell (Length) ~ 2 x 10-1 m
10-10 m
10-9 m 10-1 m
1 m10-8 m
10-7 m
10-6 m
10-5 m
10-4 m
10-3 m
10-2 m
Microspheres: Diameter ~ 1.2 m
Ag2S Nanocubes ~ 40--50 nm
Nanocrystal: Diameter ~ 16 nm
STM Image of C60 Molecular Chain
Human Hair: Diameter ~ 90m
Housefly: Length ~ 8.5 mm
ZnO Nanorod (HRTEM image)
Spacing between Atomic Planes ~ 0.6nm Stingray Red Blood
Cell~ 11.6 m
STM image of Si(111)-(7x7)
Ant’s Compound Eyes ~180m
CuS Dendrites ~ 4 m
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Scaling Down to Nanometer
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Chapter 2
Cavenagh bridge, Singapore’s oldest suspension (cantilever) bridge
SEM image of an AFM cantilever
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Cantilevers
(Wavenumber cm−1 = Hz/c)
FT-IR spectrum of ethanol molecules in liquid state
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Molecular Vibrations
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Brownian Motion
Artist’s impression of a nanobot killing a virus
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Nanobot – Artist’s Impression
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Chapter 3
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Blackbody Radiation
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One-Dimensional Potential Box
Plots of the wavefunctions y(x) corresponding to differentquantum states and the square of the wavefunction |y(x)|2
Wavefunctions
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Wavefunctions
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Three-Dimensional Potential Box
Potential box with small dimension
Potential box with large dimension
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Energy Levels in Potential Box
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Energy versus kz for quantum wire
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Potential Step
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Potential Barrier
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Energy levels of H, He+ and Li2+
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Hydrogen Spectrum
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Spherical Coordinates
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Shapes of Angular Wavefunctions
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The Stern Gerlach Experiment
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Chapter 4
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Periodic Table of Elements
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Unit cell for a variety of ionic salts
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Crystal planes
(100) planes
Miller indices - (hkl) notations are used to denote planes that intercept at positions a/h, a/k, and a/l (or some
multiples of these) of the x-, y- and z-axes respectively
z
x
y
(110) planes
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X-Ray Diffraction
For constructive interference,
path length difference = n
n = 1, 2, 3 …
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XRD Analysis
WW
KD
cos
Debye-Scherrer equation relates peak width W to the crystallite size D:
(111) (220)
(311)
2 nm
3 nm
4 nm
CdS nanocrystals
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Wave function for the interacting orbitals
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Effective overlap between AOs
MO energy level diagram
for N2 molecule
N atom
N2
1s 1s
σ(2s)
σ*(2s)
N atom
2s 2s
2p 2pσ(2p)
σ*(2p)
π(2p)
π*(2p)
σ(1s)
σ*(1s)
N≡N molecule
The electronic configuration of N2 is: (1s)2(*1s)2(2s)2
(*2s)2(2p)4(2p)2
N atom
N2
1s 1s
σ(2s)
σ*(2s)
N atom
2s 2s
2p 2pσ(2p)
σ*(2p)
π(2p)
π*(2p)
σ(1s)
σ*(1s)
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Formation of sp3 hybridized orbitals
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Van der Waals Minimum
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Hydrogen Bonding
Intramolecular hydrogen bonding within one carboxylic molecule
Hydrogen bonding between carbonyl and amide group
H–F····H–F
Hydrogen bonding between two carboxylic molecules
Simple hydrogen bonding between two diatomic molecules
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H-bonding in Proteins
Beta-pleated sheets
Alpha-helices
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H-bonding in Deoxyribonucleic acid, DNA
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Assemblies of Supramolecules
C.A.Stanier, M. J. O Connell, H. L. Anderson, W. Clegg, J. Chem. Soc. Chem. Comm., 2001, 493.M. Cesario, C. O. Dietrich-Buchecker, J. Guilhem, C. Pascard, J. P. Sauvage, J. Chem. Soc. Chem. Comm. 1985, 244.
An assembly of a rotaxane An assembly of a catenane
