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Nanofibers,

technology andapplications

Old

ich JIRSK

Nanofibers,

technology andapplications

Oldich JIRSK

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NanofibresNanofibres

What is nanofiber?Fiber with diameter in nanometer range.

Many types of polymers were processed

into nanofibers of 50 to 1000

nanometers in diameter, several orders

of magnitude smaller than conventional

fiber spinning.

What is electrospinning?Electrospinning is the process using electrostatic forces to form a fine filament

of the polymer solution.

Technical University of Liberec, Czech Republic

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NANOFIBERS

Properties

large specific surface area

high porosity

small pore size

diameter range (50 1000) nm

MaterialPolymer solutions or melts

More than 30 polymers, including polyethylene oxide, DNA,

polyaramids, and polyaniline, have been electrospun.

These fibers can be made of variety organic (nylon, polyester, acryl) or

biological polymers (proteins, collagens).

PVA, PS, PAN, but also peptide amphiphiles or cellulose.

Technical University of Liberec, Czech Republic

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Technology of nanofibers Electrospinning technology

Technical University of Liberec, Czech Republic

In the electrospinning process a high voltage is used to create an electrically charged stream of polymer solution ormelt. A high voltage electrode is linked with the polymer solution. The solution is then spun through a capillary . Dueto high voltage e lectric f ield between the tip of capillary and a grounded collector, Taylor cone is formed at the tip of

capillary producing sub-micron in diameter fibres. Fibres solidify as the polymer solvent evaporates and create aninterlinked fiber layer on the surface of the collector.

0.1 - 1gramms per hour

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N A N O S P I D E RN A N O S P I D E R

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NANOFIBRES APPLICATIONSNANOFIBRES APPLICATIONS Air and liquid filters

Wound dressings Tissue enginnering

Surface modifications

Sound absorptive materials

-etc

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Air filtration properties

of various materials

Air filtration properties

of various materials

10

20

30

40

50

60

70

80

90

100

0 50 100 150 200 250 300 350 400 450 500

Pressure drop (Pa)

Efficiency(%) meltblown

charged meltblown

glass microfibers

needle punch

PA6 nanospider

PA6/PU nanospider

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Wound dressingsWound dressings

NanofibersNanofibers

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Wound dressings - functionsWound dressings - functionsFunction of wound dressingFunction of wound dressing

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Sound absorptive materialsSound absorptive materialsProfile: Nanofibrous layer is applied by the electro spinning proces to the basic fibrous material

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Sound absorption - nanofibresSound absorption - nanofibres

0

0,2

0,4

0,6

0,8

1

100 1000 10000

f [Hz]

basic material nano-1 g.m-2 nano-0,5 g.m-2 nano-0,1 g.m-2

Basic fibrous material with the nanofibrous layers of different area densities (colored curves)

vs.

Basic material without the nanofibers (black curve)

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Thanksfor Your Attentionhanksfor Your Attention