Module A-2: SYNTHESIS & ASSEMBLY. Size – Dependent Properties. Electronic Energy Band. Size-Dependent Properties. Nanoscale: High Ratio of Surface Area to Volume. Dimensions of Materials. Size – Dependent Properties. • Nanoscale sizes can lead to different physical and chemical properties
• Nanoscale sizes can lead to different physical and chemical properties
- Optical properties
- Melting point
- Surface reactivity
• Even when such nanoparticles are consolidated into macroscale solids, new properties of bulk materials are possible.
- Example: enhanced plasticity
The melting point of gold particles decreases dramatically as the particle size gets below 5 nm
Source: Nanoscale Materials in Chemistry, Wiley, 2001
Au3+ + citrate ---> Au0 + oxidized citrate
Many factors must be considered when we approach the bottom-up nanomanufacturing by self assembly – including BBs, forces on BBs, and functional nanotechnological applications.
Forces on BBs
properties, as interactions between proximal nano- crystals give rise to new collective phenomena.
R. P. Andres
R. P. Andres, Science (1996)