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materials and their properties

macroscopic properties

phase statestrength / stiffnesselectrical conductivity

chemical ro erties

chemical compositionstructure of electron orbitals

microscopic properties

color / transparencespectroscopical properties

surface properties

densityheat conductivity

(costs of production)

(costs of handling)(recycling / disposal)

intermolecular interactionsintramolecular interactions

dipolar moment

electrical polarizationmagnetic polarization

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materials and their properties

example: portable phone

phase stateelectrical conductivity

strength / stiffness

color / transparencechemical properties

spectroscopical propertiessurface properties

densityheat conductivity

(costs of production)(costs of handling)

(recycling / disposal)

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materials and their properties

macroscopic properties

phase statestrength / stiffnesselectrical conductivity

chemical ro erties

chemical compositionstructure of electron orbitals

microscopic properties

color / transparencespectroscopical properties

surface properties

densityheat conductivity

(costs of production)

(costs of handling)(recycling / disposal)

intermolecular interactionsintramolecular interactions

dipolar moment

electrical polarizationmagnetic polarization

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materials and their properties

macroscopic properties

phase statestrength / stiffnesschemical properties

electrical conductivit

chemical compositionstructure of electron orbitals

microscopic properties

color / transparencespectroscopical properties

surface properties

densityheat conductivity

(costs of production)

(costs of handling)(recycling / disposal)

intermolecular interactionsintramolecular interactions

dipolar moment

electrical polarizationmagnetic polarization

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classical phase states

solid liquid gas

- hardly compressible

- elastic response todeformation

- hardly compressible

- viscous response todeformation

- easily compressible

- viscous response todeformation

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Pcriticalpoint

T

gastripel-point

phase boundaries

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Pcriticalpoint

over-critical

T

gas

tripel-point

phase boundaries

gas

liquid

gas

liquid

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liquid crystals

nematic smectic cholesteric

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materials and their properties

macroscopic properties

phase statestrength / stiffness 1) molecular mass:

microscopic properties

creasing

olecular

ass

gas ...liquid ...

2) intermolecular interactions:

examples:

a) London forcesb) dipolar interactionsc) hydrogen bonds

d) covalent, metallicor ionic bondsi

ncreasingstrength

in m m

gas

liquid

solid

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1) molecular mass

example: alkanes (molecular mass):

methane (16)ethane (30)

CH4

CH3CH3gas

propane (44)...

octane (114)...

hexadecane (226)

CH3CH2CH3

CH3CH

2CH

2CH

2CH

2CH

2CH

2CH

3 liquid

solid

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materials and their properties

macroscopic properties

phase statestrength / stiffness 1) molecular mass:

microscopic properties

creasing

olecular

ass

gas ...liquid ...

2) intermolecular interactions:

examples:

a) London forcesb) dipolar interactionsc) hydrogen bonds

d) covalent, metallicor ionic bondsi

ncreasingstrength

in m m

gas

liquid

solid

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2) intermolecular interactions

a) London forcesa very general interaction

acting between unchargedmolecules (e.g. alkanes)

+ - + -

po ar n erac onsact between all permanent

electrical dipoles (e.g. CO)

c) hydrogen bondsfound in all compounds with

polar X-H-bonds (e.g. water)

CO CO......

OH

H

O

H

H

OH

H

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2) intermolecular interactionsComparison of materials with similar molecular masses:

compound molecular interaction melting boilingmass point point

a) Ne neon 18 g/Mol London -249C -246Cforces

b) CO carbon 28 g/Mol + dipolar -204C -191Cmonoxide forces

c) NH3 17 g/Mol + hydrogen -40C -33C

ammonia bonds

d) H2O 18 g/Mol + strong 0C 100C

water hydrogenbonds

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materials and their properties

macroscopic properties

chemical propertiesimportant material property:resistance against corrosion

1) low chemical reactivity- noble metals (Ag, Au, Pt)

- filled electron orbitals (Ar)

microscopic properties

2) passivation- formation of a thin,

passive oxidized layer (Al)

3) use of additives that

prevent corrosion

- paint

- anti-oxidants in plastics

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electrical potentials of

metals against hydrogen:

Li lithium - 2.96-

Cd cadmium - 0.40

Co cobalt - 0.28

(all values in V against H2)

X H2

Xn+ H+

Ca calcium - 2.76Na sodium - 2.71Mg magnesium - 2.34

Al aluminum - 1.33Mn manganese - 1.10Zn zinc - 0.76Cr cromium - 0.51

Fe iron - 0.44

Ni nickel - 0.23Sn tin - 0.16Pb lead - 0.12

H2 hydrogen 0

Cu copper 0.34Ag silver 0.79

Hg mercury 0.85Au gold 1.36Pt platinum 1.60

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materials and their properties

macroscopic properties

chemical propertiesimportant material property:resistance against corrosion

1) low chemical reactivity- noble metals (Ag, Au, Pt)

- filled electron orbitals (Ar)

microscopic properties

2) passivation- formation of a thin,

passive oxidized layer (Al)

3) use of additives that

prevent corrosion

- paint

- anti-oxidants in plastics

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galvanic cell:

Zn Fe

Zn2+ Fe3+

galvanic cell under-

- +

In direct contact with zinc, iron becomesmore inert against oxidation, while zinc is

more easily oxidized. Zinc, however, formsa passivation layer.

e ron

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materials and their properties

macroscopic properties

chemical propertiesimportant material property:resistance against corrosion

1) low chemical reactivity- noble metals (Ag, Au, Pt)

- filled electron orbitals (Ar)

microscopic properties

2) passivation- formation of a thin,

passive oxidized layer (Al)

3) use of additives that

prevent corrosion

- paint

- anti-oxidants in plastics

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materials and their properties

macroscopic properties

electrical conductivity 1) metallic conductors- highly delocalized electrons- increasing resistance with

incre sin tem er ture

microscopic properties

2) semi-conductors

- electrons may be delocalizedunder certain conditions

- decreasing resistance withincreasing temperature

3) electrolytes

- conductance under chemicaldecomposition

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E

conducting band

valence band

insulator semi-conductor conductor

e-

EV

e-x

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materials and their properties

macroscopic properties

electrical conductivity1) metallic conductors- highly delocalized electrons

- increasing resistance with

incre sin tem er ture

microscopic properties

2) semi-conductors

- electrons may be delocalizedunder certain conditions

- decreasing resistance withincreasing temperature

3) electrolytes

- conductance under chemicaldecomposition

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materials and their properties

macroscopic properties

electrical conductivity1) metallic conductors- highly delocalized electrons

- increasing resistance with

incre sin tem er ture

microscopic properties

2) semi-conductors

- electrons may be delocalizedunder certain conditions

- decreasing resistance withincreasing temperature

3) electrolytes

- conductance under chemicaldecomposition

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Na+

+ -

e-

e-anode cathode

Cl -

electrolysis

Cl2 OH-