Nanofibers,technology and

applications

Oldřich JIRSÁK

Nanofibers,technology and

applications

Oldřich JIRSÁK

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

NANOFIBERS

Propertieslarge 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) orbiological polymers (proteins, collagens).

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

Technical University of Liberec, Czech Republic

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 or melt. A high voltage electrode is linked with the polymer solution. The solution is then spun through a capillary . Due to high voltage electric field between the tip of capillary and a grounded collector, Tay lor cone is formed at the tip of capillary producing sub-micron in diameter fibres. Fibres solidify as the polymer solvent evaporates and create an interlinked fiber layer on the surface of the collector.

0.1 - 1gramms per hour

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

NANOFIBRES APPLICATIONSNANOFIBRES APPLICATIONS

• Air and liquid filters• Wound dressings• Tissue enginnering• Surface modifications• Sound absorptive materials• -etc

Air filtration propertiesof various materials

Air filtration propertiesof various materials

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Pressure drop (Pa)

Effi

cien

cy (

%) meltblown

charged meltblown

glass microfibers

needle punch

PA6 nanospider

PA6/PU nanospider

Wound dressingsWound dressings

NanofibersNanofibers

Wound dressings - functionsWound dressings - functions

Function of wound dressingFunction of wound dressing

Sound absorptive materialsSound absorptive materials

Profile: Nanofibrous layer is applied by the electro spinning proces to the basic fibrous material

Sound absorption - nanofibresSound absorption - nanofibres

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f [Hz]

α

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)

Thanks for Your AttentionThanks for Your Attention