1. Lab Information Prepare photoresist – groups of 3 to 4 people
1 mg oil red (solvent red 27)
3.5 g isobornyl acrylate (IBA)
2.0 g 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (bis-GMA)
0.18 g 2,2-dimethoxy-2-phenyl-acetophenone (DMPA)
Wear gloves!
Expose photoresist with UV lamp (goggles will absorb UV)

2. Special Nanomaterials & Carbon Nanotechnology (Section 4.4.6)
Introduction to Nanotechnology

3. What are “special nanomaterials”?
Materials that are made using unique processes
Materials that have unique structures and/or properties
Examples:

4. Special Nanomaterials: Outline
Micro and Mesoporous Materials
Ex. Zeolites, Metal-Organic Framework (MOF)
Core-Shell Structures
Carbon Nanotechnology
Nanotubes
Fullerenes
Other organic molecules

5. Micro and Mesoporous Materials

6. Random Mesoporous Structures
Variety of methods of synthesis
Oxidation of metal foils using acids
Radiation-track etching
Sol-gel processing
aerogel: 75-90% porosity
xerogel: ~ 50 % porosity

7. Sol Gel Processing

8. Crystalline Mesoporous Structures: Zeolites
Crystalline aluminosilicates
First discovered in 1756
34 are naturally-occurring
3-D framework with uniformly-sized pores
Pores: ~ 0.3 – 1.0 nm in diameter
Pore volumes: ~ 0.1 – 0.35 ml/g
Applications:
Catalysts
Adsorbents/molecular sieves

9. Crystalline Mesoporous Structures: Zeolites
N&N Fig. 6.13
N&N Fig. 6.12
Various arrangements
Rings
Cages
Channels
Chains

10. MOFs
Similar to zeolites, more syntheic flexibility

11. Core-Shell Structures
Core and shell made of two different materials
Differences:
Crystal structure (lattices, arrangements of atoms)
Physical properties
Example: one metallic, one insulating
Method of synthesis

12. Core-Shell Structure Example: Metal-Polymer
Membrane-Based Synthesis
Metal particles trapped inside pores
Add polymer solution into pores and react
Use as ligand and polyimerize
Fratoddi et al. Nanoscale Research Letters 2011, 6:98

13. Membrane Based Core-Shell
Nano Lett. Sep 2006; 6(9): 2166–2171.
Au shell, polyaniline core

14. Other Core-Shell Semiconductor Passivation More Tunability
Chemistry of Materials 2011, 23, 4587–4598.
Semiconductor Passivation
More Tunability

15. Carbon Nanostructures
Variety of properties
Metallic conductor (graphite)
Semiconductor (diamond)
Insulating Polymer (hydrocarbon chains)
3-D
2-D
Variety of structures
1-D
0-D

16. Carbon Fullerenes 0-dimensional carbon structure
Usually C60, but also refers to C70, C76, Cn (n > 60)
Every carbon site on C60 is equivalent
Bonded to three other carbons
average bond is 1.44 Å (C-C is 1.46 Å; C=C is 1.40 Å)
20 hexagonal faces; 12 pentagonal faces
Diameter: Å

17. Buckminster Fuller (1895-1983):
Architect, engineer, inventor; Developed the geodesic dome

18. Synthesis of Fullerenes
Laser ablation (vaporizing graphite with a laser)
Plasma arcing of graphite or coal
Fullerenes found in the soot
Combustion synthesis
Burn hydrocarbon at low pressure

19. Carbon Nanotubes Single-Walled Carbon Nanotubes (SWCNT; SWNT)
Multi-Walled Carbon Nanotubes (MWCNT; MWNT)
Preparation:
Arc evaporation (plasma arcing)
Laser ablation
PECVD
Electrochemical methods
Addition of transition metal powder encourages SWNT growth

20. Carbon Nanotubes
Armchair
(b) Zigzag
(c) Chiral

21. Flavors of nanotubes Armchair is metallic
Zigzag/Chiral are semiconducting (small bandgap)
Most methods produce mixture
Catalysts, sorting techniques to separate
Nature 512, 61–64 (07 August 2014)

22. Properties of Carbon Nanotubes
Mechanical
Stiff and robust structures
C-C bonds in graphite (and nanotubes) is the one of the strongest bonds in nature
Flexible; do not break when bent
Conductivity
Extremely high thermal conductivity
Extremely high electrical conductivity
Potential Applications:
catalysis - hydrogen storage - biological cell electrodes
resistors - flow sensors - electron field emission tips
electronic/mechanical devices - scanning probe tips

23. Carbon Nanotube Applications (NEMS)
“Nantero is a nanotechnology company using carbon nanotubes for the development of next-generation semiconductor devices...
In the field of memory, Nantero is developing NRAM™, a high-density nonvolatile Random Access Memory.”
Cedric – computer made with SWNT
-align nanotubes
-obtain only semiconducting morphologies
- 8 micron features

24. Carbon Nanotube Applications
Gold plate ~ (100 nm)2 attached to outer shell of suspended MWCNT (on Si wafer)
“electrostatically rotate the outer shell relative to the inner core”

25. Carbon Nanotube Applications
Nanotechnology 22 (2011)
Aligned sheet of MWNT, Thermally activated

26. Other Organic Molecules
acetone
Small molecules
solvents
metabolites
reactants or monomers
Large molecules; “macromolecules”
biomolecules
e.g. DNA, proteins, lipids
carbon nanotubes
polymers

27. Organic Nanotechnology