Introduction to Nanotechnology

Module 6

Atomic and Molecular Structure

Material Properties

Source: Life on Earth biology textbook

Source: Life on Earth biology textbook

Source: Life on Earth biology textbook

Source: Life on Earth biology textbook

Source: Life on Earth biology textbook

Source: Life on Earth biology textbook

Source: Life on Earth biology textbook

Crude representation of collagen, cellulose, or a plastic polymer (and many other types of materials)

In reality this molecule is moving. . .•Left and right (stretching)•Wobbling back and forth•Vibrating up and downANDThe individual atoms may be vibrating or moving

So why don’t materials made out of these types of molecules just fall apart?

Because bonds are formed in between theindividual chains.These bonds provide elasticity, strength and cohesiveness to the structure.

Types of Unit Cells

• Cubic Unit Cell a = b = c α = β = γ = 900

• Tetragonal a =b ≠ c α = β = γ = 900

Simple

Body Centered

Face Centered

Simple Body Centered

3-4

Source: W.G. Moffatt, G.W. Pearsall, & J. Wulff, “The Structure and Properties of Materials,” vol. I: “Structure,” Wiley, 1964, p. 47.

Figure 3.2

Types of Unit Cells (Cont.)• Orthorhombic

a ≠ b ≠ c α = β = γ = 900

• Rhombohedral a =b = c α = β = γ ≠ 900

SimpleBase Centered

Face CenteredBody Centered

Simple

3-5

Source: W.G. Moffatt, G.W. Pearsall, & J. Wulff, “The Structure and Properties of Materials,” vol. I: “Structure,” Wiley, 1964, p. 47.

Figure 3.2

• Hexagonal

a ≠ b ≠ c α = β = γ = 900

• Monoclinic a ≠ b ≠ c α = β = γ = 900

• Triclinic a ≠ b ≠ c α = β = γ = 900

Types of Unit Cells (Cont.)

Simple

Simple

Simple

BaseCentered

3-6

Source: W.G. Moffatt, G.W. Pearsall, & J. Wulff, “The Structure and Properties of Materials,” vol. I: “Structure,” Wiley, 1964, p. 47.

Figure 3.2

Material Properties• Strength• Elasticity• Rigidity• Hardness• Electrical conductivity• Thermal conductivity

References• Poole, Charles P., and Frank J. Owens. Introduction to Nanotechnology. Hoboken,

NJ: J. Wiley, 2003.

• Wilson, Michael. Nanotechnology: Basic Science and Emerging Technologies. Boca Raton: Chapman & Hall/CRC, 2002.