Nano Fibres

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Fibre with diameter in nanometre range.

Polymers are processed into nanofibres of

50 to 1000 nanometres in diameter, severalorders of magnitude smaller thanconventional fibre spinning.

Provide new and improved functionalitiesthan conventional fibres.

2Material Science and Metallurgy


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Inexpensive and easy way to producenanofibres from wide range of polymers.

Uses electrostatic forces to form finefilaments.



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High Voltage is appliedto create electricallycharged solution

Spun through capillary forms Taylor cone produce fine fibres

Solidifies when polymersolvent evaporates forms interlinked fiberlayer on collector.



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Viscosity

Polymer Concentration

Weight ofPolymers

Conductivity Elasticity

Surface tension

Solution Properties

Applied Voltage

Feed rate

Needle Dia. Distance b/wNeedle & Collector

Processing Conditions

PARAMETERS

Temperature

Humidity

Pressure

Ambient Conditions



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Particle size decreases no. of atoms atsurface increases.

Surface effects become prominent. Surface area Volume ratio is very high.

Applications

1.More reactive sites exposed.2.High adsorption surface.



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Fine diameter High degree of lightscattering (e.g. : Electrospun carbon black)

Possible to obtain transparent composites.(fibre dia. < of visible light)

Excellent optical polarizers.



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Light weight

Flexibility

Permeability Strength

Toughness

Difficulty in achieving precise nanofibresdeposition

Hence deposited around a core filament



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Can be done without core usage- Polyacrylonitrile (PAN) nanofibres, reinforced

with carbon nanotubes (CNT). Flame, Chemical and Environmental

protections are areas of research.



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Electrospun mats made of nanofibres havevery small pore sizes, but total porosity isvery high.

These 2 impart high filtration efficiency. Commercially developed for industrial air

filters.

Efficiency can be increased by surface

modifications of nanofibres. Laid over a filtration medium substrate for

support



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Devices in which recognition devices arenanosized

Nanolevel property changes increasedsensitivity and resolution levels.



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Nanofibrous layer is applied to basicfibrous layer by electrospinning

Better acoustical performane Suitable candidate for noise reduction



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Incorporation of a new type of moleculescalled metal organic polyhedra and metal

organic frameworks onto polymericnanofibres

Trap dangerous gases ,then decomposethem and capture them for furtherdecontamination



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Faster / more effective healing

Biodegradability

Nanofibre structures match tissuestructures cells grow as in naturalenvironment

Hospital personnel protection against

infection higher efficiency than traditionalmaterials

Much smaller amount of drug required forthe same medical effect



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The small pores doesnt allow the microbes to penetrate the

dressing and infect wounds better healing, in contrast to normalwound dressings



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Bioactive glass is used to regenerate bonetissue.

The laser spinning makes the material

flexible, continuous and gives it ananometric structure, which helps in theproliferation and spread of bone cells.

Nanoglass fibre for bone tissueregeneration



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Polymer nanofibre membrane capturechemical warfare agents.

The nanofibres act as a substrate on whichthe nerve agents get physically adsorbedfollowed by chemical decomposition.



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Science and Engineering of PolymerNanofibres, Ramakrishna, et al., AmericanScientific Publishers.

Nanofibres : Technology and Applications,O. Jirsak.

Electrospun Nanofibres, Christopher Calvin

Call. Electrospinning

http://en.wikipedia.org/wiki/Electrospinning

http://en.wikipedia.org/wiki/Electrospinninghttp://en.wikipedia.org/wiki/Electrospinninghttp://en.wikipedia.org/wiki/Electrospinninghttp://en.wikipedia.org/wiki/Electrospinninghttp://en.wikipedia.org/wiki/Electrospinning


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Nano Fibres

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