Nanofibers,
technology and
applications
Oldřich
Oldřich JIRSÁK
JIRSÁK
Nanofibres
Technical University of Liberec, Czech Republic
What is electrospinning?
Electrospinning is the process using electrostatic forces to form a fine filament
of the polymer solution.
What is nanofiber?
Fiber with diameter in nanometer range.
M any types of polymers were processed
into nanofibers of 50 to 1000
nanometers in diameter, several orders
of magnitude smaller than conventional
fiber spinning.
Technical University of Liberec, Czech Republic
NANOFIBERS
Properties
large specific surface area
high porosity
small pore size
diameter range (50 – 1000) nm
Material
Polymer solutions or melts
M ore 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
Technology of nanofibers – Electrospinning technology
0.1 - 1g ramms per hour
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 poly mer 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.
NANOSPIDER
NANOFIBRES APPLICATIONS
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Air and liquid filters
Wound dressings
Tissue enginnering
Surface modifications
Sound absorptive materials
-etc
Air
Air filtration
filtration properties
properties
of
of various
various materials
materials
100
90
Efficiency (%)
80
70
meltblown
60
charged meltblown
50
glass microfibers
40
needle punch
30
PA6 nanospider
20
PA6/PU nanospider
10
0
50
100
150
200
250
300
Pressure drop (Pa)
350
400
450
500
Wound dressings
Nanofibers
Wound dressings - functions
Function of wound dressing
Sound absorptive materials
P rofile: Nanofibrous layer is applied by t he elect ro spinning proces to the basic fibrous material
Sound absorption - nanofibres
Basic fibrous material with the nanofibrous layers of different area densit ies (colored curves)
vs.
Basic mat erial without t he nanofibers (black curve)
1
0,8
0,6
α
0,4
0,2
0
100
1000
10000
f [Hz]
basic material
nano-1 g.m-2
nano-0,5 g.m-2
nano-0,1 g.m-2
Thanks for Your Attention