composite presentation by dr.a.lal

8/13/2019 Composite Presentation by Dr.a.lal

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Properties

Light weightgreater stiffness and

strength

Higher operating

temperature

Excellent corrosion resistant

Very good fatiguecharacteristics

Ability to Tailor the structural

properties according to

requirements

design flexibilityHigher reliability, durability

and affordability

Dissimilar materials

Differing in forms

Insoluble to each other

Physically distinctChemically inhomogeneous


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Most composites are made up of just two materials.One material (the matrix or binder) surrounds andbinds together a cluster of fibres or fragments of amuch stronger material (the reinforcement).


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Introduction

Nanomaterials is the study of how

materials behave when their dimensions

are reduced to the nanoscale.

A unique aspect of nanotechnology is the

vastly increased ratio of surface area to

volume (A/V) present in many nanoscale

materials which opens new possibilities insurface-based science, such as catalysis
http://en.wikipedia.org/wiki/Materials_sciencehttp://en.wikipedia.org/wiki/Catalysishttp://en.wikipedia.org/wiki/Catalysishttp://en.wikipedia.org/wiki/Materials_science


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A number of physical phenomena become noticeably pronouncedas the size of the system decreases.

These include statistical mechanical effects, as well as quantummechanicaleffects,

for example the quantum size effect where the electronicproperties of solids are altered with great reductions in particle size.

This effect does not come into play by going from macro to microdimensions. However, it becomes dominant when the nanometersize range is reached.

Additionally, a number of physical properties change whencompared to macroscopic systems.

One example is the increase in surface area to volume of materials.Novel mechanical properties of nanomaterials is the subject ofnanomechanicsresearch.

Their catalytic activity reveals novel properties in the interaction withbiomaterials.
http://en.wikipedia.org/wiki/Statistical_mechanicshttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Quantumhttp://en.wikipedia.org/wiki/Physical_propertieshttp://en.wikipedia.org/wiki/Nanomechanicshttp://en.wikipedia.org/wiki/Biomaterialhttp://en.wikipedia.org/wiki/Biomaterialhttp://en.wikipedia.org/wiki/Nanomechanicshttp://en.wikipedia.org/wiki/Physical_propertieshttp://en.wikipedia.org/wiki/Physical_propertieshttp://en.wikipedia.org/wiki/Physical_propertieshttp://en.wikipedia.org/wiki/Quantumhttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Statistical_mechanicshttp://en.wikipedia.org/wiki/Statistical_mechanicshttp://en.wikipedia.org/wiki/Statistical_mechanics


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What is the effect of nonmaterial?

Materials reduced to the nanoscale can suddenly showvery different properties compared to what they exhibiton a macroscale, enabling unique applications.

For instance, opaque substances become transparent(copper);

inert materials become catalysts (platinum);

stable materials turn combustible (aluminum);

solids turn into liquids at room temperature (gold);

insulators become conductors (silicon).

Materials such as gold, which is chemically inert at

normal scales, can serve as a potent chemical catalystat nanoscales.

Much of the fascination with nanotechnology stems fromthese unique quantum and surface phenomena thatmatter exhibits at the nanoscale.
http://en.wikipedia.org/wiki/Goldhttp://en.wikipedia.org/wiki/Catalysthttp://en.wikipedia.org/wiki/Catalysthttp://en.wikipedia.org/wiki/Gold


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Nanosize powder particles (a few nanometres in

diameter, also called nanoparticles) are

potentially important in ceramics, powder

metallurgy, the achievement of uniformnanoporosity and similar applications.

The strong tendency of small particles to form

clumps ("agglomerates") is a serious

technological problem that impedes suchapplications.
http://en.wikipedia.org/wiki/Nanoparticlehttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Powder_metallurgyhttp://en.wikipedia.org/wiki/Powder_metallurgyhttp://en.wikipedia.org/wiki/Powder_metallurgyhttp://en.wikipedia.org/wiki/Powder_metallurgyhttp://en.wikipedia.org/wiki/Powder_metallurgyhttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Nanoparticle


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Materials used in nanotechnology

Fullerenes and carbon forms

Nanoparticles and Colloids

F ll d b f


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Fullerenes and carbon forms

Allotropes of carbon

Aggregated diamond nanorods

Buckypaper Carbon nanofoam

Carbon nanotube

Nanoknot*

Fullerene chemistry

Bingel reaction

Endohedral hydrogen fullerene Prato reaction

Fullerenes in popular culture

Endohedral fullerenes

Fullerite

Graphene

Potential applications of carbon nanotubes

Timeline of carbon nanotubes
http://en.wikipedia.org/wiki/Allotropes_of_carbonhttp://en.wikipedia.org/wiki/Aggregated_diamond_nanorodshttp://en.wikipedia.org/wiki/Buckypaperhttp://en.wikipedia.org/wiki/Carbon_nanofoamhttp://en.wikipedia.org/wiki/Carbon_nanotubehttp://en.wikipedia.org/wiki/Nanoknothttp://en.wikipedia.org/wiki/Fullerene_chemistryhttp://en.wikipedia.org/wiki/Bingel_reactionhttp://en.wikipedia.org/wiki/Endohedral_hydrogen_fullerenehttp://en.wikipedia.org/wiki/Prato_reactionhttp://en.wikipedia.org/wiki/Fullerenes_in_popular_culturehttp://en.wikipedia.org/wiki/Endohedral_fullereneshttp://en.wikipedia.org/wiki/Fulleritehttp://en.wikipedia.org/wiki/Graphenehttp://en.wikipedia.org/wiki/Potential_applications_of_carbon_nanotubeshttp://en.wikipedia.org/wiki/Timeline_of_carbon_nanotubeshttp://en.wikipedia.org/wiki/Timeline_of_carbon_nanotubeshttp://en.wikipedia.org/wiki/Potential_applications_of_carbon_nanotubeshttp://en.wikipedia.org/wiki/Graphenehttp://en.wikipedia.org/wiki/Fulleritehttp://en.wikipedia.org/wiki/Endohedral_fullereneshttp://en.wikipedia.org/wiki/Fullerenes_in_popular_culturehttp://en.wikipedia.org/wiki/Prato_reactionhttp://en.wikipedia.org/wiki/Endohedral_hydrogen_fullerenehttp://en.wikipedia.org/wiki/Bingel_reactionhttp://en.wikipedia.org/wiki/Fullerene_chemistryhttp://en.wikipedia.org/wiki/Nanoknothttp://en.wikipedia.org/wiki/Carbon_nanotubehttp://en.wikipedia.org/wiki/Carbon_nanofoamhttp://en.wikipedia.org/wiki/Buckypaperhttp://en.wikipedia.org/wiki/Aggregated_diamond_nanorodshttp://en.wikipedia.org/wiki/Allotropes_of_carbon


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Nanoparticles and Colloids Colloid

Diamondoids Nanocomposite

Nanocrystal

Nanostructure Nanocages

Nanocomposite

Nanofabrics Nanofiber

Nanofoam

Nanoknot

Nanomesh

Nanopillar

Nanopin film

Nanoring

Nanorod

Nanoshell

Nanotube

Quantum heterostructure

Sculptured thin film

Quantum dot
http://en.wikipedia.org/wiki/Colloidhttp://en.wikipedia.org/wiki/Diamondoidshttp://en.wikipedia.org/wiki/Nanocompositehttp://en.wikipedia.org/wiki/Nanocrystalhttp://en.wikipedia.org/wiki/Nanostructurehttp://en.wikipedia.org/wiki/Nanocageshttp://en.wikipedia.org/wiki/Nanocompositehttp://en.wikipedia.org/wiki/Nanofabricshttp://en.wikipedia.org/wiki/Nanofiberhttp://en.wikipedia.org/wiki/Nanofoamhttp://en.wikipedia.org/wiki/Nanoknothttp://en.wikipedia.org/wiki/Nanomeshhttp://en.wikipedia.org/wiki/Nanopillarhttp://en.wikipedia.org/wiki/Nanopin_filmhttp://en.wikipedia.org/wiki/Nanoringhttp://en.wikipedia.org/wiki/Nanorodhttp://en.wikipedia.org/wiki/Nanoshellhttp://en.wikipedia.org/wiki/Nanotubehttp://en.wikipedia.org/wiki/Quantum_heterostructurehttp://en.wikipedia.org/wiki/Sculptured_thin_filmhttp://en.wikipedia.org/wiki/Quantum_dothttp://en.wikipedia.org/wiki/Quantum_dothttp://en.wikipedia.org/wiki/Sculptured_thin_filmhttp://en.wikipedia.org/wiki/Quantum_heterostructurehttp://en.wikipedia.org/wiki/Nanotubehttp://en.wikipedia.org/wiki/Nanoshellhttp://en.wikipedia.org/wiki/Nanorodhttp://en.wikipedia.org/wiki/Nanoringhttp://en.wikipedia.org/wiki/Nanopin_filmhttp://en.wikipedia.org/wiki/Nanopillarhttp://en.wikipedia.org/wiki/Nanomeshhttp://en.wikipedia.org/wiki/Nanoknothttp://en.wikipedia.org/wiki/Nanofoamhttp://en.wikipedia.org/wiki/Nanofiberhttp://en.wikipedia.org/wiki/Nanofabricshttp://en.wikipedia.org/wiki/Nanocompositehttp://en.wikipedia.org/wiki/Nanocageshttp://en.wikipedia.org/wiki/Nanostructurehttp://en.wikipedia.org/wiki/Nanocrystalhttp://en.wikipedia.org/wiki/Nanocompositehttp://en.wikipedia.org/wiki/Diamondoidshttp://en.wikipedia.org/wiki/Colloid


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Fullerenes The fullerenes are a class of allotropes of carbonwhich

conceptually are graphene sheets rolled into tubes orspheres.

These include the carbon nanotubeswhich are of interestdue to both their mechanical strength and their electrical

properties. For the past decade, the chemical and physical

properties of fullerenes have been a hot topic in the fieldof research and development, and are likely to continueto be for a long time.

In April 2003, fullerenes were under study for potentialmedicinal use: binding specific antibioticsto the structureto target resistant bacteriaand even target certain cancercells such as melanoma.
http://en.wikipedia.org/wiki/Allotropes_of_carbonhttp://en.wikipedia.org/wiki/Graphenehttp://en.wikipedia.org/wiki/Carbon_nanotubehttp://en.wikipedia.org/wiki/Nanomedicinehttp://en.wikipedia.org/wiki/Nanomedicinehttp://en.wikipedia.org/wiki/Antibiotichttp://en.wikipedia.org/wiki/Bacteriumhttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Melanomahttp://en.wikipedia.org/wiki/Melanomahttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Bacteriumhttp://en.wikipedia.org/wiki/Antibiotichttp://en.wikipedia.org/wiki/Nanomedicinehttp://en.wikipedia.org/wiki/Nanomedicinehttp://en.wikipedia.org/wiki/Nanomedicinehttp://en.wikipedia.org/wiki/Nanomedicinehttp://en.wikipedia.org/wiki/Nanomedicinehttp://en.wikipedia.org/wiki/Carbon_nanotubehttp://en.wikipedia.org/wiki/Carbon_nanotubehttp://en.wikipedia.org/wiki/Carbon_nanotubehttp://en.wikipedia.org/wiki/Graphenehttp://en.wikipedia.org/wiki/Allotropes_of_carbonhttp://en.wikipedia.org/wiki/Allotropes_of_carbonhttp://en.wikipedia.org/wiki/Allotropes_of_carbonhttp://en.wikipedia.org/wiki/Allotropes_of_carbonhttp://en.wikipedia.org/wiki/Allotropes_of_carbon


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The October 2005 issue of Chemistry and Biology contains anarticle describing the use of fullerenes as light-activatedantimicrobialagents.

In the field of nanotechnology, heat resistance and superconductivityare some of the more heavily studied properties.

A common method used to produce fullerenes is to send a largecurrent between two nearby graphite electrodes in an inertatmosphere. The resulting carbon plasma arc between theelectrodes cools into sooty residue from which many fullerenes canbe isolated.

There are many calculations that have been done using ab-initioQuantum Methods applied to fullerenes. By DFT and TDDFT

methods one can obtain IR, Ramanand UVspectra. Results of suchcalculations can be compared with experimental results.
http://en.wikipedia.org/wiki/Antimicrobialhttp://en.wikipedia.org/wiki/Nanotechnologyhttp://en.wikipedia.org/wiki/Superconductivityhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Plasma_%28physics%29http://en.wikipedia.org/wiki/Density_functional_theoryhttp://en.wikipedia.org/wiki/IRhttp://en.wikipedia.org/wiki/Raman_spectroscopyhttp://en.wikipedia.org/wiki/UVhttp://en.wikipedia.org/wiki/UVhttp://en.wikipedia.org/wiki/Raman_spectroscopyhttp://en.wikipedia.org/wiki/IRhttp://en.wikipedia.org/wiki/Density_functional_theoryhttp://en.wikipedia.org/wiki/Plasma_%28physics%29http://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Superconductivityhttp://en.wikipedia.org/wiki/Nanotechnologyhttp://en.wikipedia.org/wiki/Antimicrobial


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Nanoparticles

Nanoparticles or nanocrystals made of metals,semiconductors, or oxides are of interest for theirelectrical, optical, and chemical properties. Nanoparticleshave been used as quantum dots and as chemicalcatalysts.

Nanoparticles are of great scientific interest as they areeffectively a bridge between bulk materials and atomicormolecular structures. A bulk material should haveconstant physical properties regardless of its size, but atthe nano-scale this is often not the case. Size-dependent

properties are observed such as quantum confinementinsemiconductor particles, surface plasmon resonance insome metal particles and superparamagnetism inmagneticmaterials.
http://en.wikipedia.org/wiki/Nanocrystalhttp://en.wikipedia.org/wiki/Quantum_dothttp://en.wikipedia.org/wiki/Catalysthttp://en.wikipedia.org/wiki/Atomichttp://en.wikipedia.org/wiki/Molecularhttp://en.wikipedia.org/wiki/Quantum_confinementhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Surface_plasmon_resonancehttp://en.wikipedia.org/wiki/Superparamagnetismhttp://en.wikipedia.org/wiki/Magnetichttp://en.wikipedia.org/wiki/Magnetichttp://en.wikipedia.org/wiki/Superparamagnetismhttp://en.wikipedia.org/wiki/Surface_plasmon_resonancehttp://en.wikipedia.org/wiki/Surface_plasmon_resonancehttp://en.wikipedia.org/wiki/Surface_plasmon_resonancehttp://en.wikipedia.org/wiki/Surface_plasmon_resonancehttp://en.wikipedia.org/wiki/Surface_plasmon_resonancehttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Quantum_confinementhttp://en.wikipedia.org/wiki/Quantum_confinementhttp://en.wikipedia.org/wiki/Quantum_confinementhttp://en.wikipedia.org/wiki/Molecularhttp://en.wikipedia.org/wiki/Atomichttp://en.wikipedia.org/wiki/Catalysthttp://en.wikipedia.org/wiki/Quantum_dothttp://en.wikipedia.org/wiki/Quantum_dothttp://en.wikipedia.org/wiki/Quantum_dothttp://en.wikipedia.org/wiki/Nanocrystal


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Nanopartical continue...

Nanoparticles exhibit a number of special propertiesrelative to bulk material. For example, the bending ofbulk copper(wire, ribbon, etc.) occurs with movement ofcopper atoms/clusters at about the 50 nm scale. Copper

nanoparticles smaller than 50 nm are considered superhard materials that do not exhibit the same malleabilityand ductilityas bulk copper.

The change in properties is not always desirable.Ferroelectric materials smaller than 10 nm can switch

their magnetisation direction using room temperaturethermal energy, thus making them useless for memorystorage.
http://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Malleabilityhttp://en.wikipedia.org/wiki/Ductilityhttp://en.wikipedia.org/wiki/Ductilityhttp://en.wikipedia.org/wiki/Malleabilityhttp://en.wikipedia.org/wiki/Copper


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Suspensionsof nanoparticles are possible because theinteraction of the particle surface with the solvent isstrong enough to overcome differences in density, whichusually result in a material either sinking or floating in aliquid. Nanoparticles often have unexpected visibleproperties because they are small enough to confinetheir electrons and produce quantum effects. Forexample goldnanoparticles appear deep red to black insolution.

Nanoparticles have a very high surface area to volumeratio. This provides a tremendous driving force fordiffusion, especially at elevated temperatures. Sinteringcan take place at lower temperatures, over shorter timescales than for larger particles. This theoretically does

not affect the density of the final product, though flowdifficulties and the tendency of nanoparticles toagglomerate complicates matters. The surface effects ofnanoparticles also reduces the incipient meltingtemperature.
http://en.wikipedia.org/wiki/Suspension_%28chemistry%29http://en.wikipedia.org/wiki/Solventhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Goldhttp://en.wikipedia.org/wiki/Diffusionhttp://en.wikipedia.org/wiki/Sinteringhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Melting_temperaturehttp://en.wikipedia.org/wiki/Melting_temperaturehttp://en.wikipedia.org/wiki/Melting_temperaturehttp://en.wikipedia.org/wiki/Melting_temperaturehttp://en.wikipedia.org/wiki/Melting_temperaturehttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Sinteringhttp://en.wikipedia.org/wiki/Diffusionhttp://en.wikipedia.org/wiki/Goldhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Solventhttp://en.wikipedia.org/wiki/Suspension_%28chemistry%29


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Potential applications of carbon

nanotubes

Structural clothes: waterproof tear-resistant

combat jackets: MIT is working on combat jackets that use carbon nanotubes asultrastrong fibers and to monitor the condition of the wearer. [1]

concrete: In concrete, they increase the tensile strength, and halt crack propagation.

polyethylene: Researchers have found that adding them to polyethylene increases

the polymer's elastic modulusby 30%. sports equipment: Stronger and lighter tennis rackets, bike parts, golf balls, golf

clubs, golf shaft and baseball bats.

space elevator: This will be possible only if tensile strengths of more than about70 GPa can be achieved. Monoatomic oxygenin the Earth's upper atmosphere woulderode carbon nanotubes at some altitudes, so a space elevator constructed ofnanotubes would need to be protected (by some kind of coating). Carbon nanotubesin other applications would generally not need such surface protection.

ultrahigh-speed flywheels: The high strength/weight ratio enables very high speedsto be achieved.

Bridges: For instance in suspension bridges (where they will be able to replacesteel), or bridges built as a "horizontal space elevator".
http://en.wikipedia.org/wiki/MIThttp://en.wikipedia.org/wiki/Body_armorhttp://web.mit.edu/isn/http://en.wikipedia.org/wiki/Concretehttp://en.wikipedia.org/wiki/Crack_propagationhttp://en.wikipedia.org/wiki/Polyethylenehttp://en.wikipedia.org/wiki/Elastic_modulushttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Flywheelhttp://en.wikipedia.org/wiki/Flywheelhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Elastic_modulushttp://en.wikipedia.org/wiki/Elastic_modulushttp://en.wikipedia.org/wiki/Elastic_modulushttp://en.wikipedia.org/wiki/Polyethylenehttp://en.wikipedia.org/wiki/Crack_propagationhttp://en.wikipedia.org/wiki/Crack_propagationhttp://en.wikipedia.org/wiki/Crack_propagationhttp://en.wikipedia.org/wiki/Concretehttp://web.mit.edu/isn/http://web.mit.edu/isn/http://web.mit.edu/isn/http://en.wikipedia.org/wiki/Body_armorhttp://en.wikipedia.org/wiki/Body_armorhttp://en.wikipedia.org/wiki/Body_armorhttp://en.wikipedia.org/wiki/MIT


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Electromagnetic

artificial muscles Electroactive Polymers or EAPs are polymers whoseshape is modified when a voltageis applied to them. They can be used asactuatorsor sensors. As actuators, they are characterized by the fact thatthey can undergo a large amount of deformation while sustaining largeforces. Due to the similarities with biological tissues in terms of achievablestress and force, they are often called artificial muscles, and have thepotential for application in the field of robotics, where large linear movement

is often needed. buckypaper - a thin sheet made from nanotubes that are 250 times

stronger than steel and 10 times lighter that could be used as a heat sinkforchipboards, a backlight for LCD screens or as a faraday cage to protectelectrical devices/aeroplanes.

chemical nanowires: Carbon nanotubes additionally can also be used toproduce nanowires of other chemicals, such as gold or zinc oxide. These

nanowires in turn can be used to cast nanotubes of other chemicals, suchas gallium nitride. These can have very different properties from CNTs - forexample, gallium nitride nanotubes are hydrophilic, while CNTs arehydrophobic, giving them possible uses in organic chemistry that CNTscould not be used for.
http://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Polymerhttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Musclehttp://en.wikipedia.org/wiki/Buckypaperhttp://en.wikipedia.org/wiki/Heat_sinkhttp://en.wikipedia.org/wiki/LCDhttp://en.wikipedia.org/wiki/Faraday_cagehttp://en.wikipedia.org/wiki/Hydrophobehttp://en.wikipedia.org/wiki/Hydrophilehttp://en.wikipedia.org/wiki/Hydrophobehttp://en.wikipedia.org/wiki/Hydrophobehttp://en.wikipedia.org/wiki/Hydrophilehttp://en.wikipedia.org/wiki/Faraday_cagehttp://en.wikipedia.org/wiki/Faraday_cagehttp://en.wikipedia.org/wiki/Faraday_cagehttp://en.wikipedia.org/wiki/LCDhttp://en.wikipedia.org/wiki/Heat_sinkhttp://en.wikipedia.org/wiki/Heat_sinkhttp://en.wikipedia.org/wiki/Heat_sinkhttp://en.wikipedia.org/wiki/Buckypaperhttp://en.wikipedia.org/wiki/Musclehttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Polymerhttp://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Electroactive_polymers


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computer circuits: A nanotube formed by joining nanotubes of twodifferent diameters end to end can act as a diode, suggesting the possibilityof constructing electronic computer circuits entirely out of nanotubes.Because of their good thermal properties, CNTs can also be used todissipate heat from tiny computer chips. The longest electricity conductingcircuit is a fraction of an inch long. (Source: June 2006 NationalGeographic).

conductive films: A 2005 paper in Sciencenotes that drawing transparenthigh strength swathes of SWNT is a functional production technique (Zhanget al., vol. 309, p. 1215). Additionally, Eikos Incof Franklin, Massachusettsand Unidym Inc.[2]of Silicon Valley, California are developing transparent,electrically conductive films of carbon nanotubes to replace indium tin oxide(ITO) in LCDs, touch screens, and photovoltaic devices. Carbon nanotubefilms are substantially more mechanically robust than ITO films, making

them ideal for high reliability touch screens and flexible displays. Nanotubefilms show promise for use in displays for computers, cell phones, PDAs,andATMs.
http://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Science_%28journal%29http://en.wikipedia.org/wiki/Eikoshttp://en.wikipedia.org/wiki/Indium_tin_oxidehttp://en.wikipedia.org/wiki/Personal_digital_assistanthttp://en.wikipedia.org/wiki/Automated_teller_machinehttp://en.wikipedia.org/wiki/Automated_teller_machinehttp://en.wikipedia.org/wiki/Personal_digital_assistanthttp://en.wikipedia.org/wiki/Indium_tin_oxidehttp://en.wikipedia.org/wiki/Indium_tin_oxidehttp://en.wikipedia.org/wiki/Indium_tin_oxidehttp://en.wikipedia.org/wiki/Indium_tin_oxidehttp://en.wikipedia.org/wiki/Indium_tin_oxidehttp://en.wikipedia.org/wiki/Eikoshttp://en.wikipedia.org/wiki/Eikoshttp://en.wikipedia.org/wiki/Eikoshttp://en.wikipedia.org/wiki/Science_%28journal%29http://en.wikipedia.org/wiki/Diode


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electric motor brushes: Conductive carbon nanotubes have been used forseveral years in brushesfor commercial electric motors. They replacetraditional carbon black, which is mostly impure spherical carbon fullerenes.The nanotubes improve electrical and thermal conductivity because theystretch through the plastic matrix of the brush. This permits the carbon fillerto be reduced from 30% down to 3.6%, so that more matrix is present in thebrush. Nanotube composite motor brushes are better-lubricated (from the

matrix), cooler-running (both from better lubrication and superior thermalconductivity), less brittle (more matrix, and fiber reinforcement), strongerand more accurately moldable (more matrix). Since brushes are a criticalfailure point in electric motors, and also don't need much material, theybecame economical before almost any other application.

light bulb filament: alternative to in incandescent lamps.

magnets: MWNTscoated with magnetite

optical ignition: A layer of 29% iron enriched SWNTis placed on top of alayer of explosive material such as PETN, and can be ignited with a regularcamera flash.
http://en.wikipedia.org/wiki/Brush_%28electric%29http://en.wikipedia.org/wiki/Carbon_blackhttp://en.wikipedia.org/wiki/Incandescent_lampshttp://en.wikipedia.org/wiki/MWNThttp://en.wikipedia.org/wiki/Magnetitehttp://en.wikipedia.org/wiki/SWNThttp://en.wikipedia.org/wiki/PETNhttp://en.wikipedia.org/wiki/PETNhttp://en.wikipedia.org/wiki/SWNThttp://en.wikipedia.org/wiki/Magnetitehttp://en.wikipedia.org/wiki/MWNThttp://en.wikipedia.org/wiki/Incandescent_lampshttp://en.wikipedia.org/wiki/Carbon_blackhttp://en.wikipedia.org/wiki/Brush_%28electric%29


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solar cells: GE's carbon nanotube diode has a photovoltaic effect.Nanotubes can replace ITO in some solar cells to act as a transparentconductive film in solar cells to allow light to pass to the active layers andgenerate photocurrent.

superconductor: Nanotubes have been shown to be superconducting atlow temperatures.

ultracapacitors: MIT is researching the use of nanotubes bound to thecharge plates of capacitors in order to dramatically increase the surfacearea and therefore energy storage ability.[3]

displays: One use for nanotubes that has already been developed is asextremely fine electron guns, which could be used as miniature cathode raytubes in thin high-brightness low-energy low-weight displays. This type ofdisplay would consist of a group of many tiny CRTs, each providing theelectronsto hit the phosphorof one pixel, instead of having one giant CRTwhose electrons are aimed using electric and magnetic fields. Thesedisplays are known as field emission displays(FEDs).

transistor: developed at Delft, IBM, and NEC.
http://en.wikipedia.org/wiki/Solar_cellshttp://en.wikipedia.org/wiki/Photovoltaicshttp://en.wikipedia.org/wiki/Superconductorhttp://en.wikipedia.org/wiki/Superconductivityhttp://en.wikipedia.org/wiki/Ultracapacitorhttp://en.wikipedia.org/wiki/Displayshttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Phosphorhttp://en.wikipedia.org/wiki/Pixelhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Field_emission_displayhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Field_emission_displayhttp://en.wikipedia.org/wiki/Field_emission_displayhttp://en.wikipedia.org/wiki/Field_emission_displayhttp://en.wikipedia.org/wiki/Field_emission_displayhttp://en.wikipedia.org/wiki/Field_emission_displayhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Pixelhttp://en.wikipedia.org/wiki/Phosphorhttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Displayshttp://en.wikipedia.org/wiki/Ultracapacitorhttp://en.wikipedia.org/wiki/Superconductivityhttp://en.wikipedia.org/wiki/Superconductorhttp://en.wikipedia.org/wiki/Photovoltaicshttp://en.wikipedia.org/wiki/Solar_cellshttp://en.wikipedia.org/wiki/Solar_cellshttp://en.wikipedia.org/wiki/Solar_cells


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Chemical air pollution filter: Future applications of nanotube membranes

include filtering carbon dioxidefrom power plant emissions.[4] biotech container: Nanotubes can be opened and filled with

materials such as biological molecules, raising the possibility ofapplications in biotechnology.

hydrogen storage: Research is currently being undertaken into thepotential use of carbon nanotubes for hydrogen storage. They havethe potential to store between 4.2 and 65% hydrogen by weight.This is an important area of research, since if they can be massproduced economically there is potential to contain the samequantity of energy as a 50l gasoline tank in 13.2l of nanotubes. Seealso, Hydrogen Economy.[5]

water filter: Recently nanotube membranes have been developed

for use in filtration. This technique can purportedly reducedesalination costs by 75%. The tubes are so thin that small particles(like water molecules) can pass through them, while larger particles(such as the chloride ions in salt) are blocked.
http://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Biotechnologyhttp://en.wikipedia.org/wiki/Hydrogen_Economyhttp://en.wikipedia.org/wiki/Hydrogen_Economyhttp://en.wikipedia.org/wiki/Hydrogen_Economyhttp://en.wikipedia.org/wiki/Hydrogen_Economyhttp://en.wikipedia.org/wiki/Biotechnologyhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxide


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Mechanical

oscillator: fastest known oscillators (>

50 GHz).

nanotube membrane: Liquid flows up to

five orders of magnitude faster than

predicted by classical fluid dynamics.

slick surface: slicker than Teflon and

waterproof.
http://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membrane


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In electrical circuits

Carbon nanotubes have many propertiesfrom theirunique dimensions to an unusual current conductionmechanismthat make them ideal components ofelectrical circuits. Currently, there is no reliable way toarrange carbon nanotubes into a circuit.

The major hurdles that must be jumped for carbonnanotubes to find prominent places in circuits relate tofabrication difficulties. The production of electrical circuitswith carbon nanotubes are very different from thetraditional IC fabrication process. The IC fabrication

process is somewhat like sculpture- films are depositedonto a wafer and pattern-etched away. Because carbonnanotubes are fundamentally different from films, carbonnanotube circuits can so far not be mass produced.
http://en.wikipedia.org/wiki/Electrical_conductionhttp://en.wikipedia.org/wiki/Fabrication_%28semiconductor%29http://en.wikipedia.org/wiki/Sculpturehttp://en.wikipedia.org/wiki/Sculpturehttp://en.wikipedia.org/wiki/Fabrication_%28semiconductor%29http://en.wikipedia.org/wiki/Fabrication_%28semiconductor%29http://en.wikipedia.org/wiki/Fabrication_%28semiconductor%29http://en.wikipedia.org/wiki/Fabrication_%28semiconductor%29http://en.wikipedia.org/wiki/Fabrication_%28semiconductor%29http://en.wikipedia.org/wiki/Electrical_conduction


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Some other important applications

Metallic and semiconducting nanotubes

Carbon Nanotube Interconnects

Carbon Nanotube Transistors

Challenges in Electronic Design and

Design Automation

As fiber and film


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When a material is placed within a magnetic field, themagnetic forces of the material's electrons will beaffected. This effect is known as Faraday's Law ofMagnetic Induction. However, materials can react quitedifferently to the presence of an external magnetic field.This reaction is dependent on a number of factors, suchas the atomic and molecular structure of the material,and the net magnetic field associated with the atoms.The magnetic moments associated with atoms have

three origins. These are the electron orbital motion, thechange in orbital motion caused by an external magneticfield, and the spin of the electrons.


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In most atoms, electrons occur in pairs.Electrons in a pair spin in opposite directions.So, when electrons are paired together, theiropposite spins cause their magnetic fields tocancel each other. Therefore, no net magnetic

field exists. Alternately, materials with someunpaired electrons will have a net magneticfield and will react more to an external field.Most materials can be classified asdiamagnetic, paramagnetic or .ferromagnetic.


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Applications Magnetic materials encompass a wide variety of materials, which are used in a

diverse range of applications.

Magnetic materials are utilized in the creation and distribution of electricity, and, inmost cases, in the appliances that use that electricity.

They are used for the storage of data on audio and video tape as well as oncomputer disks.

In the world of medicine, they are used in body scanners as well as a range ofapplications where they are attached to or implanted into the body.

The home entertainment market relies on magnetic materials in applications such as

PCs, CD players, televisions, games consoles and loud speakers. It is difficult to imagine a world without magnetic materials and they are becoming

more important in the development of modern society.

The need for efficient generation and use of electricity is dependent on improvedmagnetic materials and designs. Non-polluting electric vehicles will rely on efficientmotors utilising advanced magnetic materials.

The telecommunications industry is always striving for faster data transmission and

miniaturisation of devices, both of which require development of improved magneticmaterials.

Metallic glasses are excellent ferromagnets. Possessing high magnetic moments,very high permeability and zero magnostriction. They are hard and corrosion resistanttherefore they are suitable for use as the magnetic head recorder. They can be easilymagnetize hence also find application in magnetic shielding , motors, transformersetc.


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Classification

Magnetic materials are classified in terms of theirmagnetic properties and their uses.

If a material is easily magnetised and demagnetised thenit is referred to as a soft magnetic material, whereas if it

is difficult to demagnetise then it is referred to as a hard(or permanent) magnetic material.

Materials in between hard and soft are almostexclusively used as recording media and have no othergeneral term to describe them.

Other classifications for types of magnetic materials aresubsets of soft or hard materials, such asmagnetostrictive and magnetoresistive materials.


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All materials can be classified in terms of their

magnetic behaviour falling into one of f ive

categories depending on their bulk magnetic

susceptibility. The two most common types ofmagnetism are diamagnetism and

paramagnetism, which account for the

magnetic properties of most of the periodic

table of elements at room temperature (see

figure).

These elements are usually referred to as

non-magnetic, whereas those which are

referred to as magnetic are actually classified

as ferromagnetic. The only other type of

magnetism observed in pure elements at room

temperature is antiferromagnetism. Finally,

magnetic materials can also be classified as

ferrimagnetic although this is not observed in

any pure element but can only be found in

compounds, such as the mixed oxides, known

as ferrites, from which ferrimagnetism derives

its name. The value of magnetic susceptible

falls into a particular range for each type of

material and this is shown in table 2 with some

examples.

Type of m agnet ic

material /MagnetismSusceptibi l i ty Atomic / Magnet ic Behaviour Example / Suscept ibi l i ty


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Diamagnetic

materialsDiamagnetism

X=rel. permeabitiy-1

Rel. per.=abs.per./per.

Of free space.

Abs.per.=B/H

Small & negative.

i.e., they cannot be

made from magnets

Atoms have no

magnetic moment.

Magnetic lines of force

are repelled by

diamagnetic solid.

Au

Cu

Si

Al2O3diamond

-2.74x10-6

-0.77x10-6

-0.3x10-5

-0.5x10-5

-2.1x10-5

paramagnetic

materials

Paramagnetism

Small & positive.

They are week

magnet.

Atoms have randomly

oriented magnetic

moments.

Magnetic line of forces

Feebly attract by

paramagnetic solid

-Sn

Pt

Mn

Fe2O3Fecl2

0.19x10-6

21.04x10-6

66.10x10-6

1.40x10-3

3.7x10-3

ferromagnetic

materials

Ferromagnetism

Large & positive,

function of applied

field, microstructuredependent.

They are very good

magnetic material.

Atoms have parallel

aligned magnetic

moments.Magnetic line of forces

Strongly attract by

ferromagnetic solid.

Fe ~100,000

Antiferromagn

etic materialsSubclass of ferromag.

Mat.Antiferromagnetism

Small & positive.

There is no net

magnetic moment in

the solid.

Atoms have mixed

parallel and anti-

parallel aligned

magnetic moments

Cr 3.6x10-6

ferrimagnetic

material

(ferrites)Subclass of ferromag.

Mat

Ferrimagnetism

Large & positive,

function of applied

field, microstructure

dependent. The

magnitude of magnetic

moment is more in one

direction then in the

other.

Atoms have anti-

parallel aligned

magnetic moments

Ba

ferrite~3

Table 2:Summary of different types of magnetic behaviour.


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Diamagneticmetals have a very weak and negativesusceptibility to magnetic fields. Diamagnetic materialsare slightly repelled by a magnetic field and the materialdoes not retain the magnetic properties when theexternal field is removed. Diamagnetic materials aresolids with all paired electron resulting in no permanentnet magnetic moment per atom. Diamagnetic propertiesarise from the realignment of the electron orbits underthe influence of an external magnetic field. Most

elements in the periodic table, including copper, silver,and gold, are diamagnetic.


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Paramagneticmetals have a small and positivesusceptibility to magnetic fields. These materialsare slightly attracted by a magnetic field and thematerial does not retain the magnetic properties

when the external field is removed.Paramagnetic properties are due to thepresence of some unpaired electrons, and fromthe realignment of the electron orbits caused by

the external magnetic field. Paramagneticmaterials include magnesium, molybdenum,lithium, and tantalum.


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Ferromagnetic materials have a large and positive susceptibility to anexternal magnetic field.

They exhibit a strong attraction to magnetic fields and are able to retain theirmagnetic properties after the external field has been removed.

Ferromagnetic materials have some unpaired electrons so their atoms havea net magnetic moment.

They get their strong magnetic properties due to the presence of magneticdomains.

In these domains, large numbers of atom's moments (1012 to 1015) arealigned parallel so that the magnetic force within the domain is strong.When a ferromagnetic material is in the unmagnitized state, the domainsare nearly randomly organized and the net magnetic field for the part as awhole is zero. When a magnetizing force is applied, the domains become

aligned to produce a strong magnetic field within the part. Iron, nickel, andcobalt are examples of ferromagnetic materials. Components with thesematerials are commonly inspected using the magnetic particle method.


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Introduction

A dielectric material is a substance that is a poorconductor of electricity, but an efficient supporterof electrostatic fields. If the flow of currentbetween opposite electric charge poles is kept to

a minimum while the electrostatic lines of fluxare not impeded or interrupted, an electrostaticfield can store energy. This property is useful incapacitors, especially at radio frequencies.

Dielectric materials are also used in theconstruction of radio-frequency transmissionlines.
http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci212048,00.htmlhttp://searchsmb.techtarget.com/sDefinition/0,,sid44_gci211871,00.htmlhttp://searchsmb.techtarget.com/sDefinition/0,,sid44_gci211742,00.htmlhttp://searchsmb.techtarget.com/sDefinition/0,,sid44_gci211742,00.htmlhttp://searchsmb.techtarget.com/sDefinition/0,,sid44_gci211871,00.htmlhttp://searchsmb.techtarget.com/sDefinition/0,,sid44_gci212048,00.html


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Characteristics

They have the value of resistivity . (Electrical resistivityalso knownas specific electrical resistance) is a measure of how strongly a

material opposes the flow of electric current. A low resistivity

indicates a material that readily allows the movement of electrical

charge. The SIunit of electrical resistivity is the ohmmetre, =RA/L).

Negative temperature coefficient of resistant ().

Large insulation resistant.

They have very conductor to hear and electricity.
http://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electrical_chargehttp://en.wikipedia.org/wiki/Electrical_chargehttp://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Ohmhttp://en.wikipedia.org/wiki/Metrehttp://en.wikipedia.org/wiki/Metrehttp://en.wikipedia.org/wiki/Ohmhttp://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Electrical_chargehttp://en.wikipedia.org/wiki/Electrical_chargehttp://en.wikipedia.org/wiki/Electric_current


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In practice, most dielectric materials are solid.Examples include porcelain (ceramic), mica,glass, plastics, and the oxides of various metals.

Some liquids and gases can serve as gooddielectric materials.

Dry air is an excellent dielectric, and is used invariable capacitors and some types oftransmission lines.

Distilled water is a fair dielectric. A vacuum is anexceptionally efficient dielectric.


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An important property of a dielectric is its ability to support anelectrostatic field while dissipating minimal energy in the form ofheat. The lower the dielectric loss(the proportion of energy lost asheat), the more effective is a dielectric material.

Another consideration is the dielectric constant, the extent to whicha substance concentrates the electrostatic lines of flux.

Substances with a low dielectric constant include a perfect vacuum,dry air, and most pure, dry gases such as helium and nitrogen.

Materials with moderate dielectric constants include ceramics,distilled water, paper, mica, polyethylene, and glass. Metal oxides, ingeneral, have high dielectric constants.


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Uses

In electrical Insulation.

They are used as insulators and

capacitors.

Used in strain gauge and sonar devices.

Formvar is a suitable insulating material

for low temp. applications. It is the trade

mane of polyvinyl formal.

As a dielectric materials.


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Introduction

A semiconductor is a solidmaterial that has electricalconductivity in between that of a conductor and that ofan insulator; it can vary over that wide range eitherpermanently or dynamically.

Semiconductors are tremendously important in

technology. Semiconductor devices, electroniccomponents made of semiconductor materials, areessential in modern electrical devices.

Examples range from computers to cellular phones todigital audio players. Silicon is used to create most

semiconductors commercially, but dozens of othermaterials are used as well.

They have widely used for making solid state devices.
http://en.wikipedia.org/wiki/Solidhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Electrical_insulationhttp://en.wikipedia.org/wiki/Semiconductor_devicehttp://en.wikipedia.org/wiki/Computershttp://en.wikipedia.org/wiki/Cellular_phoneshttp://en.wikipedia.org/wiki/Digital_audio_playerhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Digital_audio_playerhttp://en.wikipedia.org/wiki/Digital_audio_playerhttp://en.wikipedia.org/wiki/Digital_audio_playerhttp://en.wikipedia.org/wiki/Digital_audio_playerhttp://en.wikipedia.org/wiki/Digital_audio_playerhttp://en.wikipedia.org/wiki/Cellular_phoneshttp://en.wikipedia.org/wiki/Cellular_phoneshttp://en.wikipedia.org/wiki/Cellular_phoneshttp://en.wikipedia.org/wiki/Computershttp://en.wikipedia.org/wiki/Semiconductor_devicehttp://en.wikipedia.org/wiki/Semiconductor_devicehttp://en.wikipedia.org/wiki/Semiconductor_devicehttp://en.wikipedia.org/wiki/Electrical_insulationhttp://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Solid


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Semiconductor is classified by two categories Intrinsic-in which the elemental form of pure silica (Si) and Pure germanium

(Ge) are intrinsic. In intrinsic form they are not useful. They are thereforedoped by dopen to make extrinsic semiconductor.Extrinsic form are directlyuseful and are widely employed in manufacturing of solid state devises.

Extinsic- conduction in extrinsic occurs due to the presence of foreignimpurities. An extrinsic semiconductoris a semiconductorthat hasbeen doped, that is, into which a doping agenthas been introduced,giving it different electrical properties than the intrinsic (pure)semiconductor.

Doping involves adding dopant atoms to an intrinsic semiconductor,which changes the electronand holecarrier concentrationsof thesemiconductor at thermal equilibrium.

Dominant carrier concentrations in an extrinsic semiconductorclassify it as either an n-typeor p-typesemiconductor. The electricalproperties of extrinsic semiconductors make them essentialcomponents of many electronic devices.
http://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Dopanthttp://en.wikipedia.org/wiki/Intrinsic_semiconductorhttp://en.wikipedia.org/wiki/Intrinsic_semiconductorhttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Electron_holehttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Thermal_equilibriumhttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/Thermal_equilibriumhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Electron_holehttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Intrinsic_semiconductorhttp://en.wikipedia.org/wiki/Intrinsic_semiconductorhttp://en.wikipedia.org/wiki/Dopanthttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/N-type


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n-typeor p-typesemiconductor

The phrase 'n-type' comes from the negative charge ofthe electron. In n-type semiconductors, electrons are themajority carriersand holes are the minority carriers. N-type semiconductors are created by doping an intrinsicsemiconductor with donor impurities. In an n-typesemiconductor, the Fermi energy levelis greater thanthe that of the intrinsic semiconductor and lies closer tothe conduction bandthan the valence band.

P-type semiconductors

Band structure of a p-type semiconductor. Dark circles inthe conduction band are electrons and light circles in thevalence band are holes. The image shows that the holesare the majority charge carrier.
http://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Conduction_bandhttp://en.wikipedia.org/wiki/Valence_bandhttp://en.wikipedia.org/wiki/P-type_semiconductorhttp://en.wikipedia.org/wiki/P-type_semiconductorhttp://en.wikipedia.org/wiki/P-type_semiconductorhttp://en.wikipedia.org/wiki/P-type_semiconductorhttp://en.wikipedia.org/wiki/Valence_bandhttp://en.wikipedia.org/wiki/Conduction_bandhttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/P-typehttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/N-typehttp://en.wikipedia.org/wiki/N-type


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N-type semiconductors

Extrinsic semiconductors with a larger electronconcentration than hole concentration are known as n-type semiconductors.

The phrase 'n-type' comes from the negative charge ofthe electron. In n-type semiconductors, electrons are themajority carriersand holes are the minority carriers.

N-type semiconductors are created by doping an intrinsicsemiconductor with donor impurities.

In an n-type semiconductor, the Fermi energy level isgreater than the that of the intrinsic semiconductor andlies closer to the conduction bandthan the valence band
http://en.wikipedia.org/wiki/N-type_semiconductorhttp://en.wikipedia.org/wiki/N-type_semiconductorhttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Conduction_bandhttp://en.wikipedia.org/wiki/Valence_bandhttp://en.wikipedia.org/wiki/Valence_bandhttp://en.wikipedia.org/wiki/Valence_bandhttp://en.wikipedia.org/wiki/Valence_bandhttp://en.wikipedia.org/wiki/Conduction_bandhttp://en.wikipedia.org/wiki/Conduction_bandhttp://en.wikipedia.org/wiki/Conduction_bandhttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Fermi_energyhttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/Charge_carriershttp://en.wikipedia.org/wiki/N-type_semiconductorhttp://en.wikipedia.org/wiki/N-type_semiconductorhttp://en.wikipedia.org/wiki/N-type_semiconductorhttp://en.wikipedia.org/wiki/N-type_semiconductorhttp://en.wikipedia.org/wiki/N-type_semiconductor


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P-type semiconductors

As opposed to n-type semiconductors, p-typesemiconductors have a larger hole concentration thanelectron concentration.

The phrase 'p-type' refers to the positive charge of the hole.

In p-type semiconductors, holes are the majority carriersand electrons are the minority carriers.

P-type semiconductors are created by doping an intrinsicsemiconductor with acceptor impurities.

P-type semiconductors have Fermi energy levels below the

intrinsic Fermi energy level.The Fermi energy level lies closer to the valence band than

the conduction band in a p-type semiconductor.

Utilization of extrinsic
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Utilization of extrinsic

semiconductors Extrinsic semiconductors are components of many common electrical devices. Asemiconductor diode(devices that allow current flow in only one direction) consists of

p-type and n-type semiconductors placed in junction with one another. Currently,most semiconductor diodes use doped silicon or germanium.

Transistors (devices that enable current switching) also make use of extrinsicsemiconductors. Bipolar junction transistors (BJT) are one type of transistor. Themost common BJTs are NPN and PNP type. NPN transistors have two layers of n-type semiconductors sandwiching a p-type semiconductor. PNP transistors have two

layers of p-type semiconductors sandwiching an n-type semiconductor. Field-effect transistors (FET) are another type of transistor implementing extrinsic

semiconductors. As opposed to BJTs, they are unipolar and considered either N-channel or P-channel. FETs are broken into two families, junction gate FET (JFET)and insulated gate FET (IGFET).

Other devices implementing the extrinsic semiconductor:

Lasers

Solar cells Photodetectors

Light-emitting diodes

Thyristors
http://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Transistorshttp://en.wikipedia.org/wiki/Transistorshttp://en.wikipedia.org/wiki/Bipolar_junction_transistorshttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/JFEThttp://en.wikipedia.org/wiki/Laserhttp://en.wikipedia.org/wiki/Solar_cellhttp://en.wikipedia.org/wiki/Photodetectorhttp://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Thyristorshttp://en.wikipedia.org/wiki/Thyristorshttp://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Photodetectorhttp://en.wikipedia.org/wiki/Solar_cellhttp://en.wikipedia.org/wiki/Solar_cellhttp://en.wikipedia.org/wiki/Solar_cellhttp://en.wikipedia.org/wiki/Laserhttp://en.wikipedia.org/wiki/JFEThttp://en.wikipedia.org/wiki/JFEThttp://en.wikipedia.org/wiki/JFEThttp://en.wikipedia.org/wiki/JFEThttp://en.wikipedia.org/wiki/JFEThttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/Field-effect_transistorhttp://en.wikipedia.org/wiki/Bipolar_junction_transistorshttp://en.wikipedia.org/wiki/Bipolar_junction_transistorshttp://en.wikipedia.org/wiki/Bipolar_junction_transistorshttp://en.wikipedia.org/wiki/Bipolar_junction_transistorshttp://en.wikipedia.org/wiki/Bipolar_junction_transistorshttp://en.wikipedia.org/wiki/Transistorshttp://en.wikipedia.org/wiki/Transistorshttp://en.wikipedia.org/wiki/Diode


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Introduction

Superconductors are those elements, compounds andalloys of metal and nonmetals which exhibits extraordinary magnetic and electrical behavior at extremelylow temperatures (near absolute zero). Such lowtemperatures are not practically favorable for wide

application. Superconductors, materials that have no resistance tothe flow of electricity, are one of the last great frontiers ofscientific discovery. Not only have the limits ofsuperconductivity not yet been reached, but the theoriesthat explain superconductor behavior seem to beconstantly under review.

Superconductors have the ability to conduct electricitywithout the loss of energy.


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Properties of super conductors

Super conducting materials exhibit thefollowing extraordinary properties below

their critical temperatures.

The magnetic flux density, B=0.

The relative permeability, r=0.

The specific resistant, =0.

The magnetic susceptibility, =-1.

The power ( copper) loss, I2R=0.


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Types On the basis of working Temperature.

i. low temp. super cond.ii. High temp. super cond.

On the basis of kind of material.

i. metallic super conductor

ii. Inter metallic compound superconductor

iii. Ceramic super conductor.

iv. Alloy super conductors

On the basis of kind of material.i. magnetic grade super conductor

ii. Nonmagnetic grade super conductor

S d i i


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Superconductivity

Superconductivityis a phenomenon occurring in certain materialsat extremely low temperatures, characterized by exactly zeroelectrical resistanceand the exclusion of the interior magnetic field.

The electrical resistivityof a metallic conductordecreases graduallyas the temperature is lowered.

However, in ordinary conductors such as copper and silver,

impurities and other defects impose a lower limit. Even nearabsolute zeroa real sample of copper shows a non-zero resistance.

The resistance of a superconductor, on the other hand, dropsabruptly to zero when the material is cooled below its "criticaltemperature". An electrical current flowing in a loop ofsuperconducting wire can persist indefinitely with no power source.

Like ferromagnetismand atomic spectral lines, superconductivity isa quantum mechanicalphenomenon. It cannot be understood simplyas the idealization of "perfect conductivity" in classical physics.

A li ti
http://en.wikipedia.org/wiki/Materialhttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Electrical_resistivityhttp://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/Absolute_zerohttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Ferromagnetismhttp://en.wikipedia.org/wiki/Atomic_spectral_linehttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Perfect_conductorhttp://en.wikipedia.org/wiki/Perfect_conductorhttp://en.wikipedia.org/wiki/Perfect_conductorhttp://en.wikipedia.org/wiki/Perfect_conductorhttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Quantum_mechanicshttp://en.wikipedia.org/wiki/Atomic_spectral_linehttp://en.wikipedia.org/wiki/Atomic_spectral_linehttp://en.wikipedia.org/wiki/Atomic_spectral_linehttp://en.wikipedia.org/wiki/Atomic_spectral_linehttp://en.wikipedia.org/wiki/Atomic_spectral_linehttp://en.wikipedia.org/wiki/Ferromagnetismhttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Absolute_zerohttp://en.wikipedia.org/wiki/Absolute_zerohttp://en.wikipedia.org/wiki/Absolute_zerohttp://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Electrical_conductorhttp://en.wikipedia.org/wiki/Electrical_resistivityhttp://en.wikipedia.org/wiki/Electrical_resistivityhttp://en.wikipedia.org/wiki/Electrical_resistivityhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Material


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Applications Superconducting magnetsare some of the most powerful electromagnetsknown.

They are used in MRIand NMRmachines and the beam-steering magnets used in

particle accelerators. They can also be used for magnetic separation, where weakly magnetic particles are

extracted from a background of less or non-magnetic particles, as in the pigmentindustries.

Superconductors have also been used to make digital circuits(e.g. based on theRapid Single Flux Quantumtechnology) and RF and microwave filtersfor mobilephonebase stations.

Superconductors are used to build Josephson junctionswhich are the building blocksof SQUIDs(superconducting quantum interference devices), the most sensitivemagnetometersknown. Series of Josephson devices are used to define the SI volt.Depending on the particular mode of operation, a Josephson junctioncan be used asphoton detectoror as mixer. The large resistance change at the transition from thenormal- to the superconducting state is used to build thermometers in cryogenicmicro-calorimeterphoton detectors.

Other early markets are arising where the relative efficiency, size and weightadvantages of devices based on HTS outweigh the additional costs involved.

Promising future applications include high-performance transformers, power storagedevices, electric power transmission, electric motors(e.g. for vehicle propulsion, as invactrainsor maglev trains), magnetic levitation devices, and Fault Current Limiters.However superconductivity is sensitive to moving magnetic fields so applications thatuse alternating current(e.g. transformers) will be more difficult to develop than thosethat rely upon direct current
http://en.wikipedia.org/wiki/Superconducting_magnethttp://en.wikipedia.org/wiki/Electromagnethttp://en.wikipedia.org/wiki/Magnetic_resonance_imaginghttp://en.wikipedia.org/wiki/NMRhttp://en.wikipedia.org/wiki/Particle_acceleratorhttp://en.wikipedia.org/wiki/Pigmenthttp://en.wikipedia.org/wiki/Digital_circuithttp://en.wikipedia.org/wiki/Rapid_single_flux_quantumhttp://en.wikipedia.org/wiki/RF_and_microwave_filterhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Josephson_junctionhttp://en.wikipedia.org/wiki/SQUIDhttp://en.wikipedia.org/wiki/Magnetometerhttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Josephson_junctionhttp://en.wikipedia.org/wiki/Detectorhttp://en.wikipedia.org/wiki/Mixerhttp://en.wikipedia.org/wiki/Calorimeterhttp://en.wikipedia.org/wiki/Detectorhttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/SMEShttp://en.wikipedia.org/wiki/SMEShttp://en.wikipedia.org/wiki/Electric_power_transmissionhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Vactrainhttp://en.wikipedia.org/wiki/Maglev_trainhttp://en.wikipedia.org/wiki/Magnetic_levitation_devicehttp://en.wikipedia.org/wiki/Fault_Current_Limitershttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Fault_Current_Limitershttp://en.wikipedia.org/wiki/Magnetic_levitation_devicehttp://en.wikipedia.org/wiki/Maglev_trainhttp://en.wikipedia.org/wiki/Vactrainhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Electric_power_transmissionhttp://en.wikipedia.org/wiki/SMEShttp://en.wikipedia.org/wiki/SMEShttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Detectorhttp://en.wikipedia.org/wiki/Calorimeterhttp://en.wikipedia.org/wiki/Calorimeterhttp://en.wikipedia.org/wiki/Calorimeterhttp://en.wikipedia.org/wiki/Mixerhttp://en.wikipedia.org/wiki/Detectorhttp://en.wikipedia.org/wiki/Josephson_junctionhttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Magnetometerhttp://en.wikipedia.org/wiki/SQUIDhttp://en.wikipedia.org/wiki/Josephson_junctionhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/RF_and_microwave_filterhttp://en.wikipedia.org/wiki/Rapid_single_flux_quantumhttp://en.wikipedia.org/wiki/Digital_circuithttp://en.wikipedia.org/wiki/Pigmenthttp://en.wikipedia.org/wiki/Particle_acceleratorhttp://en.wikipedia.org/wiki/NMRhttp://en.wikipedia.org/wiki/Magnetic_resonance_imaginghttp://en.wikipedia.org/wiki/Electromagnethttp://en.wikipedia.org/wiki/Superconducting_magnet


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Introduction

A biomaterial is any material, natural or man-made, that comprises whole or part of a livingstructure or biomedical device which performs,augments, or replaces a natural function.

or a nonviable material used in a medical device,

intended to interact with biological systems

or

A biomaterial is essentially a material that isused and adapted for a medical application

Bi t i l A li ti


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Biomaterial Applications

Biomaterials are used in: Joint replacements

Bone plates

Bone cement

Artificial ligaments and tendons Dental implants for tooth fixation

Blood vessel prostheses

Heart valves

Skin repair devices Cochlear replacements

Contact lenses


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Ti alloy and carbon fiber-X-ray equipments

Liquid crystal polymer- optical fiber

Separation membranes- medical and

biotechnology.

High temp. super conductor- medical

imagine machine, magnetic resonance

imaging (MRI)


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composite presentation by dr.a.lal

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