Materials science is an interdisciplinary field that studies the structure and properties of various materials. It applies concepts from physics, chemistry, and engineering. The document discusses several classes of materials - ionic crystals, covalent materials, metals and alloys, semiconductors, superconductors, polymers, composites, ceramics, glasses, and catalysts. It provides examples and applications for each type of material, highlighting their importance across different industries like transportation, energy, electronics, and more.

1. INTRODUCTION TO MATERIALS
SCIENCE
POORNAPRAJNA INSTITUTE OF SCIENTIFIC RESEARCH
BENGALURU.
Lecture By : Vijaykumar .S.M

2. Materials science is an interdisciplinary field applying the synthesis
characterization and properties of material to various areas of science and
engineering.
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 .

3. CLASSES OF MATERIALS
IONIC CRYSTALS
COVALENT MATERIALS
METAL & ALLOYS
SEMICONDUCTORS
SUPERCONDUCTORS
POLYMERS
COMPOSITE MATERIALS
 CERAMICS
INORGANIC GLASSES
CATALYSTS

4. IONIC CRYSTALS
 ionic Bond is Formed by transfer of electrons
Example: NaCl,KCl,MgCl2 etc
Synthesis :
NaCl is currently produced by evaporation of seawater or brine from
other sources.
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.

5. APPLICATION OF IONIC CRYSTALS
 NaCl is Used for cooking purpose which make food tasty.
 preservation of cheese, dairy products, meat, pickles and
sauces.
 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
intake.
KCL It is used in preparation of salt bridge which
connects both the half concenteration cells.

6. COVALENT MATERIALS
Example :Diamond, Graphite, Fullerene etc
Covalent bond formed by the Sharing of electrons
DIAMOND
 highest hardness and thermal conductivity of any bulk
material.
 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
saw blades.
 Polishing pads – It is used polish hard surface

7. GRAPHITE
 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.
FULLURENE
 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
rings .
Fullerenes are currently applied in cosmetics and sports
goods industries .
 fullerenes are also used in slow drug delivery in a body

8. METALS&ALLOYS
 Metallic bonding is the bonding between atoms
within metals.
 Alloy is homogeneous mixture of two or more
elements
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

9. 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 ,
surgical instruments.
 Brass can be used for the metallic coatings of
several lock ,Watch etc.

10. SEMICONDUCTORS
 the bonding is covalent (electrons are shared between atoms). Their
electrical properties depend strongly on minute proportions of dopants.
Examples: Si, Ge etc
Dopants:
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.

11. 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

12. SUPERCONDUCTORS
 An element , intermetallic alloy or compound that will conduct electricity
without resistance below certain Temperature.
Example: YBa2Cu3O7(-178°C),Pb(-265.83°C)etc.
PROPERTIES SUPERCONDUCTORS
1.Meissner effect :
Superconductors are diamagnetic compounds which repel
magnetic field.
2.Josephson effect:
When 2 superconductors sheets are separated by small thin insulating material the
current can pass through without any voltage.

13. APPLICATION OF SUPERCONDUCTORS
 Based on Meissner effect trains can be made to
"float" on strong superconducting magnets,
virtually eliminating friction between the train and
its tracks.
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.

14. SYNTHETIC POLYMERS
 Polymer: High molecular weight molecule made up of a small repeat
unit (monomer).
A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A-A
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.

15. Synthesis of Nylon
Decanedioyl dichloride in
C2H2Cl4
1,6-diaminohexane in
aqueous sodium carbonate.
NYLON 6,10
6 indicates the no carbon atoms in amine compound
10 indicates the no of carbon atoms in carbonyl chloride

16. APPLICATION OF SYNTHETIC POLYMER
Polypropylene the polymer we are using from morning to night

17. COMPOSITE MATERIALS
 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
1.High Strength
2.Light Weight
3.Design Flexibility
•Transfer Load to Reinforcement
•Temperature Resistance
•Chemical Resistance
•Tensile Properties
•Stiffness
•Impact Resistance

18. 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.

19. CERAMICS
Ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent
cooling.
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
1.Whitewares clays
2.Refaracotories Have high Silicon or Aluminium oxide content.
3.Abrasives. Natural garnet, diamond, Silicon carbide.

20. 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.

21. GLASSES
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
3. Molding.
4. Annealing.
5. shaping.
6. Marketing .

22. 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
decorative arts.

23. CATALYST
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.
Operational Difficulties
1. Corrosive and toxic.
2. difficult to handle.
3. effluent disposal.
4. product separation.
Solid Acid catalyst
• Zeolites aluminosilicate
• Heteropolyacids H3PW12O40
• Sulfated zirconia So4
-2 /Zr02
• Mixed oxides Al2O3 ,ZnO

24. Zeolite
Zeolites are micro porous crystalline aluminosilicates with Si & Al
Tetrahedral Framework .
Calcination
Tetrapropyl
ammonium bromide

25. Acidity arises from Framework aluminium

26. SHAPE SELECTIVITY IN ZEOLITES
Reactant selectivity
Reactant molecules are to large to diffuse through
the Zeolite pore
Product selectivity
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.

28. Magnetic levitation train Magnetic levitation
Synthesis of Nylon Composite materials