Solids Solids The Neglected “State” Of The Neglected “State” Of

ChemistryChemistry

Material ScienceMaterial Science

Chem ical Material

G as

S olid s M eta ls C eram ics P o lym ers C om p os ites

Solids Liquid

   Types of Types of mattermatter: element, compound, mixture: element, compound, mixture Types of Types of elementselements: : metalsmetals, , nonmetalsnonmetals, semimetals, semimetals Types of Types of structurestructure: crystalline, amorphous: crystalline, amorphous Types of Types of bondingbonding: : metallicmetallic, , ioionicnic, , covalentcovalent, ,

intermolecular forces intermolecular forces

  metalsmetals ceramics/glassceramics/glass polymerspolymersmetallicmetallic elements elements metalsmetals & & nonmetalsnonmetals or or nonmetalsnonmetals

sseemmiimmeettaallss & & nonmetalsnonmetals

element or mixtureelement or mixture compound or mixture ofcompound or mixture of mostly mostly compoundscompounds compoundscompounds

  crystallinecrystalline ceramics = crystallineceramics = crystalline mostly mostly

amorphous w/ amorphous w/ glass = amorphous regions of glass = amorphous regions of crystallinity crystallinity

  metallicmetallic bonding bonding ioionicnic bonding andbonding and covalentcovalent bonding bonding

withwith network covalent bonding weak network covalent bonding weak intermolecular intermolecular forcesforces

Types of Bonding Types of Bonding

Type of Type of bondingbonding

MetallicMetallic IonicIonic CovalentCovalent IntermoleculIntermolecular Forcesar Forces

Type of Type of elements elements involvedinvolved

Between MetalsBetween Metals Between Metals Between Metals and Nonmetalsand Nonmetals

Between Between Nonmetals Nonmetals

Between Between Molecules Molecules

Givers & or Givers & or takers of takers of electronselectrons

Between giversBetween givers Between givers Between givers and takers and takers

Between takersBetween takers

DescriptionDescription Valence e- roam Valence e- roam freely between freely between many atoms. many atoms. Sea of electrons Sea of electrons

Transfer e- Transfer e-

Makes (+) and Makes (+) and (-) ions that are (-) ions that are attracted to attracted to each othereach other

Share e- Forms Share e- Forms discrete discrete moleculesmolecules

Hold covalently Hold covalently bonded molecules bonded molecules together as a together as a solidsolid

Type of Type of material material formedformed

Solid metals and Solid metals and alloysalloys

Ceramics and Ceramics and glassglass

Polymers and Polymers and some some ceramics/glassceramics/glasses es

Helps form solid Helps form solid polymers polymers

Strength of Strength of bondbond

Relatively Relatively strongstrong

Very strongVery strong Very strong Very strong WeakWeak

Properties Properties producedproduced

Good Good conductors, conductors, workable, workable, corrode easilycorrode easily

Brittle, hard, Brittle, hard, high melt high melt temps, temps, nonconductors nonconductors as solids, don’t as solids, don’t corrode corrode

Insulators, Insulators, don’t corrodedon’t corrode

Help determine a Help determine a lot of properties lot of properties of covalent of covalent compounds compounds (polymers) (polymers)

amorphous

crystalline

Simple cubic

Face-centered cubic(FCC)

Body-centered cubic(BCC)

Hexagonal close packed(HCP)

Most Common Metal Crystal Most Common Metal Crystal StructuresStructures

BCC BCC BBody ody CCenteredentered CCubicubic FCC FCC FFaceace CCenteredentered CCubicubic HCP HCP HHexagonalexagonal CCloselose PPackack

FCCFace-centered cubic

BCCBody-centered cubic

Workability Which crystal structure is more workable?

Many slip planes or few slip planes? Tightly packed or loosely packed? (more or less

“gappiness”?) Ice cube tray demo

Type of Type of crystal crystal

structurestructure

Closely Closely packed?packed?

Many slip Many slip planes?planes?

WorkabilitWorkabilityy

FCCFCC

BCCBCC

HCPHCP

Crystal Structures & Crystal Structures & MetalsMetals

BCCBCC FCCFCC HCPHCP OtherOtherChromiumChromium AluminumAluminum Cobalt Cobalt ManganeseManganese

Iron (<912°C)Iron (<912°C) CalciumCalcium MagnesiumMagnesium TinTin

MolybdenumMolybdenum CopperCopper TitaniumTitanium

SodiumSodium GoldGold ZincZinc

TungstenTungsten Iron (>912°C)Iron (>912°C)

LeadLead

NickelNickel

PlatinumPlatinum

SilverSilver

Thermal Shock DemoThermal Shock Demo

Types of glass Types of glass soda-lime glasssoda-lime glass borosilicate glassborosilicate glass fused silica glassfused silica glass

Types of GlassTypes of Glass

Softening temp Softening temp

Soda Lime glass (cheap) Soda Lime glass (cheap) windows windows 12851285f f 696696cc

Borosilicate (better) Borosilicate (better) beakersbeakers 14361436ff 780780cc

96% Silica96% Silica (better) (better) 28862886ff 15861586cc

Fused SilicaFused Silica (best) (best) 28762876ff 15801580cc

Thermal ShockThermal Shock

 

Material Material Coefficient of Coefficient of Thermal Thermal

Expansion Expansion

Fused Silica GlassFused Silica Glass (cm/cm x °C)(cm/cm x °C)

Borosilicate GlassBorosilicate Glass 66 X 10 X 10-7-7

Aluminosilicate Aluminosilicate GlassGlass

3333 X 10 X 10-7-7

PorcelainPorcelain 4444 X 10 X 10-7-7

Soda-Lime GlassSoda-Lime Glass 6060 X 10 X 10-7-7

Mild SteelMild Steel 8585 x 10 x 10-7-7

AluminumAluminum 110110 X 10 X 10-7-7

Category Purpose Metal oxides

Glass former Gives atomic structure – makes up backbone of network solid

SiO2 (silica) - primary Also oxides of: B, Ge, P, As, V

Modifier Lower melt temp,Makes it easier to work w/

Oxides of alkali metals *(Na2O & K2O) and alkaline earth metals **(CaO & MgO)

Intermediate Acts as either former or modifier based on other ingredients present

Oxides of: Al, Sb, Pb, Zn, and sometimes B

*make it chemically less stable **restore some stability

Glass type Ingredients Uses Advantages Disadvantages

Soda-lime (flint)(most common)

Silica (SiO2)Soda (Na2O)Lime (CaO)

Windows, bottles, etc.

Low price,Forms shapes easily

Low thermal shock resistance

Borosilicate Silica (SiO2)Soda (Na2O)Alumina (Al2O3)Boron oxide (B2O3)

Lab glasswareCookware Lamp bulbs(Pyrex)

Withstands thermal shock better and higher temps

More expensive,Harder to work

Lead-alkali(lead crystal)

Silica (SiO2)Sodium oxideLead oxide

Art glass,Expensive glassware

Sparkle,High electrical resistance

Toxicity,Doesn’t w/stand thermal shock or high temp