INTRODUCTION TO MATERIALS
POORNAPRAJNA INSTITUTE OF SCIENTIFIC RESEARCH
Lecture By : Vijaykumar .S.M
Materials science is an interdisciplinary field applying the synthesis
characterization and properties of material to various areas of science and
What is MATERIAL SCIENCE ?
What Properties we are searching in a material ?
1. Strength , Hardness , flexibility.
2.Thermal ,magnetic and electrical Properties.
3. Stability .
4. Catalyst (Acidic or basic )
5. Reusability and eco friendly .
6. Low Cost.
Based on above properties apply them in day today Material .
ionic Bond is Formed by transfer of electrons
Example: NaCl,KCl,MgCl2 etc
NaCl is currently produced by evaporation of seawater or brine from
Mg(OH)2+ 2 HCl → MgCl2(aq) + 2 H2O
Properties of Ionic Crystals
1. Solid Crystals have high melting point.
2. They Conduct electricity in molten state.
3. Low thermal conductivity.
4. Soluble in polar solvents.
APPLICATION OF IONIC CRYSTALS
NaCl is Used for cooking purpose which make food tasty.
preservation of cheese, dairy products, meat, pickles and
CaCl2 salt is used as Road salt to remove snow fallen on
road in Cold countries .it lowers the freezing point water.
Potassium chloride produced is used for making fertilizer
since the growth of many plants is limited by their potassium
KCL It is used in preparation of salt bridge which
connects both the half concenteration cells.
Example :Diamond, Graphite, Fullerene etc
Covalent bond formed by the Sharing of electrons
highest hardness and thermal conductivity of any bulk
A diamond is a transparent crystal of tetrahedral bonded
carbon atoms (sp3)
diamond lattice face centered cubic structure
Cutting and Drilling - diamonds are frequently embedded in
Polishing pads – It is used polish hard surface
Graphite has a layered, planar structure with hexagonal
lattice of Carbon atoms (SP2 ).
graphite powder with clay mixed in as a binding agent are
used in synthesis of pencil.
Fullerene is molecule composed entirely of carbon, in the
form of a hollow sphere.
Carbon is SP2 hybridization.
Fullerenes consist of 20 hexagonal and 12 pentagonal
Fullerenes are currently applied in cosmetics and sports
goods industries .
fullerenes are also used in slow drug delivery in a body
Metallic bonding is the bonding between atoms
Alloy is homogeneous mixture of two or more
Example : copper ,Aluminum , Brass, Stainless steel etc.
Properties of metals and alloys
1.High tensile strength.
2.They exhibit magnetic properties.
3.High Electrical conductivity.
Cupro – Nickel alloy
APPLICATION OF METALS AND ALLOYS
Due to Their electric properties they are used
in electric wire and Electrical devices .
Stainless steel alloy is milled into coils, sheets, plates,
bars, wire, and tubing to be used in cookware, hardware ,
Brass can be used for the metallic coatings of
several lock ,Watch etc.
the bonding is covalent (electrons are shared between atoms). Their
electrical properties depend strongly on minute proportions of dopants.
Examples: Si, Ge etc
Boron (3 rd group element )
Phosphorus (5th group element)
PROPERTIES OF SEMICONDUCTORS
1. They are crystalline and amorphous
2.The conductivity properties lie In-between insulator and conductors.
3. Their conductivity varies with temperature.
APPLICATION OF SEMICONDUCTORS
Si wafer in photovoltaic cells to convert light energy
to electric energy.
Semiconductor memory uses semiconductor-
based integrated circuits to store information.
A transistor is a semiconductor device used
to amplify and switch electronic signals
An element , intermetallic alloy or compound that will conduct electricity
without resistance below certain Temperature.
1.Meissner effect :
Superconductors are diamagnetic compounds which repel
When 2 superconductors sheets are separated by small thin insulating material the
current can pass through without any voltage.
APPLICATION OF SUPERCONDUCTORS
Based on Meissner effect trains can be made to
"float" on strong superconducting magnets,
virtually eliminating friction between the train and
Speed :581 KPh in shanghai.
SQUID's are capable of sensing a change in a
magnetic field over a billion times weaker than the
force that moves the needle on a compass . With this
technology, the body can be probed to certain depths
without the need for the strong magnetic fields
associated with MRI's.
Polymer: High molecular weight molecule made up of a small repeat
example : polyester ,nylon Bakelite etc.
Types of polymers:
1. Thermoplastics: can be processed by melting (several cycles of
heating and cooling are possible for thermally stabilized polymers)
example: PVC,PET etc
2. Thermosets: cannot be melted or dissolved to be processed: chemical
decomposition occurs before softening.
example: Vulcanized rubber Bakelite.
Synthesis of Nylon
Decanedioyl dichloride in
aqueous sodium carbonate.
6 indicates the no carbon atoms in amine compound
10 indicates the no of carbon atoms in carbonyl chloride
APPLICATION OF SYNTHETIC POLYMER
Polypropylene the polymer we are using from morning to night
Two inherently different materials that when combined together produce a material
with properties that exceed the constituent materials.
Composite materials consist of two main materials.
1.Reinsforcement(Strong load carrying material) EX: aramide, carbon ,fiberglass
2.Matrix (imbedded weaker material) EX: polypropylene ,polyvinyl chloride etc.
Composite Materials offers
•Transfer Load to Reinforcement
APPLICATION OF COMPOSITE MATERIALS
Carbon fiber composites with polymer matrices, have
become the advanced composite materials for aerospace,
due to their high strength, high Modulus and low cost.
Helmet and bullet proof jacket Made Up of
Aramide Composite material
Fiber-reinforced plastics have reached the stage
where they could be used for making wheels.
Ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent
Example: clay ,Mixed oxides like alumina Zirconia Etc
PROPERTIES OF CERAMICS
1. Ceramics are Strong solid inert materials.
2. They withstand chemical erosion due to Acid and Caustic.
3. These can withstand high temperature of about 1000 °C to1600°C.
TYPES OF CERAMICS
2.Refaracotories Have high Silicon or Aluminium oxide content.
3.Abrasives. Natural garnet, diamond, Silicon carbide.
APPLICATION OF CERAMIC MATERIALS
WHITE WARES are used in including tableware, wall
tiles, pottery products and sanitary ware
REFRACTORIES are used in making fire
bricks silica crucible and ovens. Due to
there low thermal conductivity and high
strength to temperature
Sandpaper is a very common coated abrasive.
Glass is an amorphous (non-crystalline) solid material and
typically brittle and optically transparent.
Silica(SiO2) is a common fundamental constitute of glass.
Synthesis of glass
1. Mixture of soda ash ,limestone, sand
and broken glass in dry condition.
2. send to furnace and heat to 1600°C
6. Marketing .
APPLICATION OF GLASSES
Borosilicate glasses formerly called Pyrex are often used
laboratory reagents due to their resistance to chemical
corrosion and heat
fancy glass started to become
significant branches of the
Catalyst is substance which alters the rate of reaction without itself undergoing
any chemical change in the reaction
Acid catalyzed reaction usually catalysed by acids
Ex:H2SO4, HCl, AlCl3, HF,BF3 etc.
1. Corrosive and toxic.
2. difficult to handle.
3. effluent disposal.
4. product separation.
Solid Acid catalyst
• Zeolites aluminosilicate
• Heteropolyacids H3PW12O40
• Sulfated zirconia So4
• Mixed oxides Al2O3 ,ZnO
Zeolites are micro porous crystalline aluminosilicates with Si & Al
Tetrahedral Framework .
SHAPE SELECTIVITY IN ZEOLITES
Reactant molecules are to large to diffuse through
the Zeolite pore
Product are bulky to diffuse out of the pore .
They are converted into less bulky group.
Restricted Transition state Selectivity
Reaction involving transition state would
require more space than available in the
cavities or pores.
Magnetic levitation train Magnetic levitation
Synthesis of Nylon Composite materials