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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-