Nanofibers, technology and applicationsnanoteam/events/ws2006/jirsak.pdf · Technology of...

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Transcript of Nanofibers, technology and applicationsnanoteam/events/ws2006/jirsak.pdf · Technology of...

  • 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

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    0 50 100 150 200 250 300 350 400 450 500

    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

    0

    0,2

    0,4

    0,6

    0,8

    1

    100 1000 10000

    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