1. Nanoparticle Surface Characterization by X-Ray Photoelectron Spectroscopy http://www.phi.com/Interface/PHI%20Interface%20Spring%2005.pdf

2. What is Nanotechnology? Nanoscale science: investigates the properties of matter in the critcal range of 1nm – 100 nm. Nanotechnology: Is building and using devices from 1 nm – 100 nm. Nano = 10 -9

3. What Leads to Unsual Properties? Any solid or liquid has 2 components: surface bulk

4. The Macroscopic Case One drop of water: 100,000 bulk molecules per 1 surface molecule

5. Another Example... 2 surface layers vs. ~10,000,000 internal layers 2 surface layers vs. ~5,000,000 internal layers Percentage of surface: 0.000002% vs 0.000004%

6. Shrinking Down to the Nanoscale 5% 10% 50% 100% Properties of surface atoms/molecules now affect the overall properties. C 60

7. Properties Change According to Size! Different sizes of gold particles = different optical properties.

8. Nano is all about surface! Surfaces are thin. Most surface coatings are organic. Boyen, H.-G.; Kastle, G.; Weigl, F. et al. Science 2002, 297, 1533-1536. Nanoparticle Surfaces: What’s the Problem?

9. http://www.almaden.ibm.com/st/scientific_services/materials_analysis/xps/ XPS: How Does it Work? X-Ray ejected electron KE electron = h  X-ray – BE electron

10. XPS Spectrometer: Basic Components Settle, F., ed. Handbook of Instrumental Techniques for Analytical Chemistry. Prentice Hall. 1997.

11. PeakPositionArea% C1sCarbon- ID 1285.501457.152%Pristine C 60 2287.45489.7518%Mono-oxidized C 3289.73836.6730%Di-oxidized C