IMOS Midterm Review

Properties of Clay

• high plasticity (manipulated at room temp.)

• good cohesion (maintains shape)

• high strength under compression (after drying and baking)

• poor tensile strength

• opaque

• insulator

• can be dried

• can be chemically transformed (heating above 1000C, shrinks, forms Si-O-Si bond)

Structure of clay

• Si has 4 bonds (Si-O-Si)

• Al has 6 bonds (Al-O-Al)

• Oxygen has 2 covalent bonds (Si-O-Al)

Kaolinite (China clay)

• 1:1 ratio (O-T-O-T)

• lower shrink to swell capacity

• heated <500C = drying can be reversed

• heated >1000C = stoneware dishes

Montmorillonite

• 2:1 ratio (T-O-T-interlayer-T-O-T)

• most common

• large shrink to swell capacity

Temper

non-plastic materials used to prevent shrinkage and cracking during drying and firing of vesels (ex. bone, charcoal, wood ash, sand, crushed sandstone, crushed limestone, crushed volcanic rock, crushed shells)

Primary v. Secondary clays

• primary: found at the site of formation

• secondary: washed downstream

factors for types of clay

• minerals

• glaciation

• ratio

Cuneiform

• oldest written story (2700 BC)

• account of King Ur’s superhuman strength and journey for immortality

• influence Illiad and Odyssey

History of clay

• Paleolithic: clay figurines

• Mesolithic: Japanese hunter-gatherers used clay pots for cooking

• Neolithic: sun-dried clay bricks in Israel, (oldest inhabited cities); crops stored in clay

• 7000 BC: Chatal Huyuk Clay Society

• 5000: potters wheel

• 4000BC: cuneiform tablets

Ancient uses of clay

• building materials (Great Ziggurat of Ur)

• writing

• cooking

• storage

• sling ammunition

• medical (Armenian bole medicine drink)

• musical instruments (ocarina flute)

Modern uses of clay

• sealing of oil drilling, landfills, and dams

• building materials

• odor absorbents

• pottery

• toothpaste

• cosmetics

• paint

• gasoline production

• papermaking

• cement production

• byproduct of phosphate mining

• chemical filtering

• organic farming

• quick-clot combat gauze

• hazardous waste clean-up

Carbon capture

• contains olivine (MgSiO4)

• traps Co2 into solid form

• captures up to 1/3 of weight in CO2

• could remove up to 1.7 trillions lbs of CO2 (5% of excess CO2 per year)

Affordances v. Constraints

• affordances: durable, hard, watertight, thermal conductivity

• constraints: brittle

Catalhoyuk clay society

mound settlement; entangled with clay

Theory of Entanglement

1. humans depend on things

2. things depend of things

3. things depend on humans (chains of interdependence)

4. humans depend of things that depend on humans/other things

Things

an assembling or bringing together of properties (potential and actualized)

Material entanglement

• influences social and cultural traits over time

• creates “thingworlds”

• new materials are selected if they fit within existing entanglements

• social change is not dependent on human intervention

Rare Earths

• not easily smelted

• hard to isolate

• often found in clay

• polluting to extract

• chemically similar (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, gd, Tb, Dy, Ho, Er, Tm, Yb)

Uses of rare earths

• low-energy LEDs

• strong magnets

• wind turvines

• electrical vehicles

• polishing lgass

• alloying agent for stell

• phone LEDs

Extraction of rare earths

• China extracts 63%

  • byproduct of steel production

  • restricted exports and caused a the price spike

  • removed export restrictions and dropped worldwide prices

• source may not be sustanible (critical material)

Rare earth sustanibility

• massive recycling effort

• use less waste during extraction

Properties of Gold

• color: gold, butter yellow

• hardness: 2-3

• element name: Au

• very dense: gold m³ = 19,300 kg

• most ductile

• most malleable

• can be optically transparent

• does not oxidize

• does not combine/react with other elements often

• does not react with acids

• good electrical conductor

Properties of Silver

• color: silver-white

• hardness: 2.5-3

• very malleable

• very ductile

• oxidizes (changes color)

• naturally occurring as chloride or sulfide

• good electrical conductor

• good thermal conductor

• most lustrous metal

Gold v. Silver Properties

• soft

• conductive

• currency metals

• weak metallic bonds

• extra electron

Method of Extraction

1. amalgamation

2. cyanidation

3. liquidation

4. slucing

5. Cupellation

6. Parting

Amalgamation

extracting gold from the rock by 1) dissolving crushed gold ore with mercury 2) boiling off mercury

Cyanidation

• extracting gold rocks by dissolving gold in cyanide solution

• high percentage of gold extraction

• potentially toxic

Liquidation

extracting gold and silver from copper by 1) mixing with leab 2) heating until lead melts 3) pour off lead 4) following with cupellation

Slucing

extracting gold from graving using gravity (think sifting during goldrush)

Cupellation

extracting silver from lead by 1) heating lead sulfide 2) lead oxidizies at 960C 3) silver is left behind

• 1 ton of lead = 1 lb of silver

• toxic lead pollutes waterways

Parting

separating gold and silver from each other by 1) heating with salt 2) forms silver chloride 3) turn into silver

Ancient History of Gold (40,000 BC-50 BC)

• used in Egypt for burials

• first coins are made in Asia Minor

• Alexander the Great leads the largest military campaign sponsored by gold

• Greeks and Jews in Alexandria practiced alchemy

• Julius Caesar bring back gold from Gaul to repay Rome’s debts

Modern History of Gold (700 AD-1899 AD)

• Gold is discovered in Brazil and becomes the largest producer

• 17 lb nugget is found in North Carolina

• the first goldrush sparked in North Carolina

• California Goldrush is triggered and hastens Western settlement

• Gold is discovered in New South Wales, AUS

• USS Central America sinks 30,000 lbs of gold near North Carolina coast

• Gold and silver found in Nevada

• Gold is found in South Africa and has become the majority of mining

• Gold is discovered in salmon river and created the Klondike Goldrush

Contemporary History of Gold (1900-Present)

• Engelhard Corp. introduces a way to print gold on surfaces

• Niels Bohr, Mac Von Laue, and James Frank make discoveries using gold

• George de Hevesy dissolved Nobel Prizes to hide from Nazis

• USS Central America is discovered (only 20% of gold is recovered)

• total Gold discovered = 187,000 tons = all from metors

Modern Uses of Gold

• currency standard until WWII

• used in jewlery and awards

• usefil in microelectronic industry

• used for decorative purposes

• used for red coloring in glass

• used as reflector (space face shields)

• used in cockpits

Modern Uses of Silver

• used in decorative arts

• used in photography and photographic firm

• used as a conductor of electricity and heat

• used for coins (90% of coin)

• used for jewelry and silverware

Reasons to Use Alloys

• keeps costs down

• makes gold stronger

• changes color

Karat System

• 24 kt = 100% (very soft)

• 18 kt = 75%

• 14 kt = 58%

• 12 kt = 50%

• 10 kt = 42%

• <10 kt = not gold in US

Intrisic v. Extrinisc Value

• Intrinsic: naturally occurring value

• Extrinsic: value deemed by society (use in technology, medicine, electronics)

Money v. Currency v. Coins

• money: medium of exchange

• currency: a form of money guaranteed by a territory or government

• coins: a form of money and currency

Roles of Money

1. medium of exchange

2. standard of value (comparison of goods)

3. way of storing value

4. means of payment

Characteristics of Money

1. durability

2. divisibility

3. portability

4. homogeneity

5. acceptability

6. limited/stable supply

History of Gold/Silver as Money

• precious metals described as wealth in the Old Testament

• first record in cuneiform tablet

• first form as hack-silver

• first datable coins from Ephesus (electrum coins = less gold = scam)

• Ancient Egypt: kites of silver

• Ancient Greek: drachma and electrum coin

• India: silver-punched coin

• China: knife money and bronze spade-shaped coin

Nanotech Size

1 billionth of a meter

Modern Uses of Nanoparticles

• cars

• iPod

• computers

• washing machines

• clothing

Nanoparticles and Interaction with Light

• small size changes color and interaction with light

• 25 nm = red

• 50 nm = green

• 100 nm = orange

Pasmon Resonance

changing the size of particles changes how they interact with sound

Gold Nanoparticles

• gold core and silica shell

• absorb light in infared wavelengths

• used in thermal ablation of tissue

• tissue absorption is minimal

• penetration is optimal

Uses for Nanomaterials in Medicine

• drug delivery

• chemotherapeutics

• hyperthermia

• therapeutic agent

• carrying of imaging agent

• release of drugs

Methods of Formation of Nanomaterials

• colvalent organic sythesis

• self-assembly

• crystal formatino

• laser ablation

• grinding

• milling

• fabrication

Cement v. concrete

• cement is binder for concrete

• concrete is the composite (clinker + sand + rock)

Clinker process

• <700C = water is lost

• 700-900C = calcination (CaCO3 = CaO + CO2)

• 1150-1200C = liquid phase

• 1250-1450C = clinker nodules form

• after cooling = add gypsum to control setting

• clinker is ground into Portlad Cement

Bitumen

various mixtures of hydrocarbons with nonmetallic derivatives that occur naturally after heat-refining natural substances

Properties of Bitumen

• polymeric material (carbon, nitrogen, oxygen, hydrogen, sulfur)

• not a unique molecular composition

• found as natural surface deposits

• easily collected

• easily processed

• compositionally stable at <300F

Uses for Bitumen

• applied as coating/adhesive

• used for paving and roofing

Advantages of concrete

• can be mixed offsite

• cures at room temp.

• moldable into any shape

• cheap

Disadvantages of concrete

• relative durability

• CO2 emission (7% of worldwide release)

  • 1 ton of concrete = 1 ton of CO2

Future for concrete

• use non-fossil fuels for heating (solar power)

• green cement uses recycled material

• zerocrete uses 100% recycled Flyash based cement

• self-healing concrete uses bacteria and calcium lactate and heal cracks

Steel v. concrete

• compression: good v. good

• tension: good v. bad

• thermal expansion coefficient is the same

• alkaline environment reduces corrosion

Composites

a material constructed from two or more components in greater physical or chemical properties are derived from the combination of compositions or structures

Properties of composites

• componenets remain physically seperated

• not naturally occuring

• matrix and dispered phase

• dependent on concentrartion, size, shape, distribution, orientation

concrete history

• Ancient Greece used lime and pebbles

• Romans use Roman concrete

• Roman Empire falls and roman concrete recipe is lost

• Middle Ages concrete is weak

• John Smeaton discovers how to make cement hydraulic

• USA uses cement for the Erie Canal

• Portland Cement is invented

• reinforced concrete is invented

• first reinfoced concrete bridge is built in San Fransisco

Portland Cemenet

C + A + S + H + water + sand + rock

Roman concrete

• used for compression structures (cantenary)

• used different varieties for the dome of Parthenon

• used for roads, buildings, aqueducts

• sets underwater

• self-healing properties

Roman concrete composition

• quick lime formed from limestone and heat (CaCO3 = CaO + CO2)

• fine pozzolana (volcanic ash replaces sand (Al2O3 + SiO2)

• Water (H2O)

• C+ A + S + H

Greek v. Roman architecture

• doric

• ionic

• corinthian

Class order of Romans

colessium seating reinforces class order

Properties of Copper and Bronze

• metals

• malleable

• opaque

• electrical conductor

• thermall conductor

• shiny, hard appearance

Copper v. Bronze

• pure element v. alloy of copper and impurity (arsenic or tin)

• melting point at 1084C v. 950C

• hardness of 80 MPa v. 700 MPa

• yield strength of 70 MPa v. 220 MPa

methods to strengthen bronze

• plastic deformation (permanent)

• elastic deformation (temporary) (dislocations → plastic deformation)

• work hardening (add dislocations)

• cold-rolling (increase tensile strength)

• impurtities (block disolations)

Copper reaction

• CuCO3 + heat = 2Cu + CO2

• 2CuCo2 + O2 = 2CO

• CuO + CO = Cu + CO2

Smelting process

• calls for mixing of ore with charchoal

• resource intensive

  • 140 lbs of wood = 20 lbs of charchol

  • 2 lbs of CuCo2 (malachite) = 1lb copper

• crucible and furnace

Phase diagram of Arsenic

• x-axis = composition (As)

• y-axis = temp.

• 6.8% at 685C is max solubility in copper

Arsenic alloy

• produces altered color

• increases the hardness of copper

• lower melting point

• oxidizes during smelting

• produces AsO3 bi-product (toxic)

Tin alloy

• increases strength

• heat treat ment changes strength

• adding too much tin can cause copper to be weaker

Tin v. Arsenic alloy

• dissolve more tin than arsenic (<15%)

• less toxic

• harder to find than arsenic

Copper Age

• 5500-3000 BC

• coppersmiths drew correlations between sources, conditions, and properties of copper

• deposits’ purity depends on the region

• used arsenic and tin as impurities

Bronze Age

• 3300-1200 BC

• process of smelting

• Otzi mummy is proof of copper smelting

• King Solomon’s temple

• parallel discoveries of copper around the world

• social impacts (health, mining, exploration, and experimentation)

• Trade developed around copper

  • England was the source of tin for Europe

  • Afghanistan also developed

• casting technology created productino of art, tools, and weapons

Trade of Bronze Age

• Egypt had gold

• Afghanistan had tin (tin was precious metal)

• Turkey had good metallurgists

• very entangled society

End of Bronze Age

• 200 yrs. of drought, mass starvation, and earthquakes

• ports shut down, centers are not used, and the tin supply chain stops

• sea people attack Egypt and Hittites

• society breaks down

• iron and Phencians rise

Annealing

cold treatment (less brittle, more efficient)

Copper ingots

circular shaped (England); ox-hide shaped (Mediterranean)

Copper ores

mMalachite (oxidized), Fahlerz (sulphides)

Pure Copper v. 10% Tin Copper Alloy

• melting point 1083C v. 1000C

• cast hardness: 50 HB v. 100 HB

• cold-worked hardness: 100 HB v. 230 HB

Metallurgy importance

1. technological: new skills became necessary and common

2. economic: raw and finished materials became abundant

3. social: introduces new scales of value and social divisions

Coppersmiths

• Germany

• Spain

• mythological smiths (Dwarfs)

Solar cells/Photovoltaic material

something that converts light into electricity; needs to beable to break bonds and create electrons and holes

Impacts of photovoltaics and solar cells

• 50% of CO2 comes from electricity generation

• 50-70% of the world relies of fossil fuels

• solar energy produces 50x less CO2 than fossil fuels

• solar energy is 300x cheaper than 40 years ago

• industry growth is making solar energy cheaper

• some regions need >9% of land area to produce enough energy

• hard to recycle Si at the end of life

Grid parity

new energy cost = grid cost

Semiconductor materials

• Si

• CdTe

• CIGS

• Pervoskites

Properties of Ceramics

• inorganic, nonmetal solid

• brittle

• high melting point

• poor conductor

• waterproof

• chemically resistant (iconic and colvalent bonds)

• crystallinity

Crystallinity

varies from crystalline to semi-crystalline to amorphous

Crystalline v. Amorphous

• crystalline: long-range structural order

• amorphous: lacking long-range structural order (ex. oxides, borides, polymers, and metals)

Vitrification

• transformation of atomic/molecular structure

• requires >1200C (for clay)

Plasticity

water layers can slide pass each other

Properties of Glass

• inorganic, nonmetallic solid

• brittle

• high melting point

• poor conductor

• stoff

• waterproof

• chemically resistant (ionic and colvalent bonds)

• amorphous (no crystallinity)

Operational Sequence

accounting an accounting of a system's procedures for start-up and shut-down, response to varying conditions, and certain scheduled operations

Operational sequence v. entanglement

• operation sequence: steps of a process to make a thing

• entanglement: how things and people are dependent on each other

Flinknapping

controlled reduction of glass-like rock (ex. fluted Clovis points)

• requires the right kind of rock

• skills for applying controlled force

• produce flakes and blades with/ sharp edges

• an infinite variety of forms

Bifacial reduction

planned reduction of the core through successive function or applications