electrospinning process and its application in the textile
TRANSCRIPT
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CNR – ISMACIstituto per lo Studio delle Macromolecole
Sede di Biellawww.bi.ismac.cnr.it
Electrospinning processand its application in the textile field
Electrospinning research group
A. Varesano G. Mazzuchetti
A. Aluigi
C. Vineis
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KnowKnow--howhow
•Fibres science
•Physical, chemical and microscopic textile materials characterization
•Modification of surface properties of fibres and textiles – finishing treatments
•New fibres from waste textile and agricultural products
•Handle, wear properties and comfort of textile
•Biotechnologies in the textile industry
•Technological processes: low temperature plasma (LTP), electrospinning, wet and melt spinning
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Electrospinning process
Polymer filaments using a electrostatic forceFormahls 1934-1944
Electrodes
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Filter media:Liquid filtrationGas filtrationMolecule filtration
Medical and Life Science:Natural extra-cellular matrixPorous membrane for skinTubular shapes for blood vessels and nerve regenerationThree dimensional scaffolds for bone and cartilage regenerationDrug delivery carrier Wound dressing
Other Areas:Electromagnetic interference shieldingLCD and photovoltaic devices Ultra -lightweight spacecraft materials
Application areas
25%
15%
60%
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Applications in textile fieldApplications in textile field
Sportswear
Leisure
•Thermal insulation
•Vapour resistance
•Lightness
•End use performance
•Comfort
•chemical and biological gas
•Anti vapour barriers
• Bacteria barrier
•Comfort
Protective cloths
Media filters
• High durability and easy filter cleaning• High efficiency• Trapping of tiny unfriendly particles
with diameter < 0,5 µµµµm
Nanofibres properties:
•Large surface-to-volume ratio
•High effective porosity
•Small pore size
•Low apparent density
•High surface cohesion
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Electrospinning device for polymer solutionCNR ISMAC Biella
Schematic of the electrospinning setup
High - voltage power supply: 0-30 kVMetering pump: 0.1-0.001 ml/hMetallic needle: 0.20-0.65 mmØCollector (rotanting) : 5.5 cmØ
Characteristics electrospinning device
Electric field
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Fundamental aspect electrospinning process
60 fps
4500 fps
Emisferical surface of the fluid at the tip of the capillary tube
REF > ST
Increasing the electric field intensity the emisferical surface elongates a conical shape –Taylor cone
When intensity electrostatic field attaints a critical value the repulsive electrostatic force REF overcomes the surface tension ST, the charged jet of the fluid is ejected from the Taylor cone tip
The polymers solution, during the course from the tip of the capillary tube to the collector, undergoes whipping process where the solvent evaporation occurs
5000x
Fluid-dynamic instability zone
Jet trajectory
Linear
Typical whip like motion
Electrospun nano-fibres web: a typical random distribution of the nano fibres on the collector
Electrospun mat: final product
Electrospinning parameters
System parameterSolution properties Molecular weight
Polymer architecture
Concentration
Conductivity
Surface tension
Process Parameters
Electrical potential at the capillary tip
Gap – distance between the tip and the collector
Flow rate of the polymer solution
Viscosity
Ambient conditions
Hydrostatic pressurein the capillary tube
TemperaturePressure
Fibres diametersFibres diameters Defects /BeadsDefects /Beads
electrical voltageelectrical voltage
gap gap –– electrodes distanceelectrodes distance
surface tensionsurface tension
polymers concentration polymers concentration
viscosity solutionviscosity solution
ParametersParameters
System and processes parameters: influence on fibres diameters and defects 1/2
Beads
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System and processes parameters: influence on fibres diameters, defects and morphology 2/2
Polymer molecular
weight
Droplet
Beads
Flow rate
Diameter
Beads
Solvent volatility
Nanofibres with pores
Droplets Beads
250 nm
Drops
100 nm
From Zheng-Ming Huang et al., Composite Science and Technology, 63 (2003), 2223-2253
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2
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Fibres diameter [nm] vs. Electrical Voltage [kV]
20000x
PEO/ Water, 5% p/pPEO/ Water, 5% p/p
15 15 kVkV, , 0.01 ml/min0.01 ml/min
nm
Diameters distribution
ddmm = 251 = 251 nmnm
20000x
PEO/ Water, 5% p/p,PEO/ Water, 5% p/p,
20 20 kVkV, , 0.01 ml/min0.01 ml/min
nm
Diameters distribution
ddmm = 190 = 190 nmnm
15000x
PEO/Water, 5% p/p,PEO/Water, 5% p/p,30 30 kVkV, , 0.01 ml/min0.01 ml/min
nm
Diameters distribution
d d mm= 172 = 172 nmnm
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Electrospinning device for polymer melt
Polypropylene electrospun condition:•T1: 230°C •T2: 280-290°C •T3: 100-140°C•T4: 85-95°C
Seungsin Lee et al. , Developing protective textile materials as barriers to liquid penetration using melt electrospinnig, Journal of applied polymer science, vol.102, 3340-3437 (2006)
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Filtration 1/3
Particles < 0.5 µµµµm
Coarse Particles
Particles > 0,5 µµµµm
Filtration Mechanisms
Mechanical separation
Inertial impact
Diffusion
AdsorptionNanofibres !Nanofibres !
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Filtration 2/3Electrospinning process:PEO nanofibre deposition
PET non-woven Air permeability: 2510 m/h
PET non-woven + nanofibres web
Cross-sectionFront viewFront view
Collector
PET non-woven
•Trapping of tiny unfriendly particles
with diameter < 0,5 µµµµm
•High efficiency
•High durability and easy filter cleaning
From F. Dotti, A. Varesano, A. Montarsolo, A. Aluigi, C. Tonin, G. Mazzuchetti, J. Ind. Textiles, 37, 2/ October 2007, 151-162
Performance request to filter media
Trapping of tiny unfriendly particles
with diameter < 0,5 µµµµm
Pz = f(d*t -1)Pz = pore sized = fibre diametert = exposition time
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Filtration 3/3
From L. Li, et al., J. Eng. Fibers Fabrics, 1(1) (2006).(Available on: http://www.jeffjournal.org)
Filtration efficiency is improved by nanofibre webs .Filtration efficiency increases as coverage level i ncreasesSimilar life with nanofiber filter and standard fil ter
PA6 nanofibres on cellulose-based air filter
High efficienty
930.0250.361Respirable>1 micron
920.0030.037Sub-micron
Cellulose +nanofibers
860.060.441Respirable>1 micron
680.010.031Sub-micron
Cellulose
Dust reduction%Inside dust
[mg/m3]Outside dust
[mg/m3]Filter
Use the nanofibers filter resulted 4 timesless penetration of sub-micron dust
From T.H. Grafe, K.M. Graham, Nonwovens in Filtration Fifth International Conference, Stuttgart (GER) 2003.
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Protective cloths 1/2
Air permeability: f(d*s-1)
Comfort
Good breathability
Good water vapour diffusion
Barrier performance
but
Barrier performance
Air permeability
Comfort
Goal High protection as well as an acceptable level of comfort
From F. Dotti, A. Varesano, A. Montarsolo, A. Aluigi, C. Tonin, G. Mazzuchetti, J. Ind. Textiles, 37, 2/ October 2007, 151-162
PET non-woven
Air permeability: 2510 m/h
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Nonwoven + microporous membraneNonwoven + electrospun membrane
Protective cloths 2/2
020406080
100120140160180
94 95 96 97 98 99 100
Protection %
Air
perm
eabi
ty [c
m3 /s
/cm
2 ]
microporousmembrane
electrospunmembrane
woven workcloth
Electrospun membrane:
A good compromise among protection and comfort
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Problems connected to electrospinning application in textile field
Productivity:
multi jet solution?
other systems ?
Electrospinning feeding:
from polymer solution ?
from polymer melt ?
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Productivity 1/3
Multi jet device
Mono jet: from 10 µµµµl/min to 10 ml/min
Multi jet* : from 22.5 µµµµl/cm 2min to 22.5 ml/cm 2min
*inter capillary distance: 1 cmdensity: 2 capillaries/cm2
Jets pushed away from their neighbours by Coulombicforces applied from the latter
From S.A. Theron et al., Multiple jets in electrospinning: experiment and modelling, Polymer, 46, (2005) 2889-2899
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Productivity 2/3
a = layer of magnetic liquid ; b = layer of polymeric solution; c e d = counter electrode located at a
distance H;e = high voltage source; f = electromagnet
Needleless electrospinning
From A.L.Yarin et al., Upward needless electrospinning of multiple nanofibres, Polymer, 45 (2004), 2977-2980
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Productivity 3/3
Needleless electrospinning:Elmarco Nanospider®
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Electrospinnig feed
From polymer solution
•Problems connected to removal and to recycling of organic solvents.
•No difficult in the capillaries cleaning
•Greater environmental impact respect to electrospinng from polymer melt
From polymer melt
•Problems connected to thermal control of process room and to high viscosity of polymer melt
•Problems connected to cleaning of the capillaries
•No solvent use
•Possibility to produce nanofibres of polymers as polyethylene, polypropylene and polyester
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Electrospinning research activities on the textile field
Process
Feedingsystem
Product
Collectors for electrospun
fibres
Cross-linking nanofibre web
on textile support
Physical and
Mechanical
performance
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Bibliography• 1. M. Ming Huang et al., A rewiew on polymer nanofibers by electrospinning and their application in
nanocomposites, Composites Science and Technology, 63, 2003• 2. A. Montarsolo et al., Potenzialità e Applicazioni delle Nanofibre prodotte mediante Elettrofilatura
per l’Innovazione Tessile, Convegno NanoItaltex Milano 12 luglio 2005 • 3. G. Mazzuchetti et al, Relazione finale Progetto LATT, Regione Piemonte 2005• 4. A. Aluigi ed altri, Elettrofilatura per la produzione di nanofibre, Nanotec IT newsletter, giugno
2005l.5. G. Mazzuchetti et ai, Il processo di elettrofilatura per la produzione di nanofibre, Convegno Moda e Tecnologia, 29-30 settembre Padova
• 5. Defil, La filtrazione dell’aria, www.defil.it• 6. F. Dotti et al. Electrospun porous mats for air/gas filtration, Journal of industrial textiles, 37, 2007,
151-162• 7.Seungsin Lee et al. , Developing protective textile materials as barriers to liquid penetration using
melt electrospinnig, Journal of applied polymer science, vol.102, 3340-3437 (2006) • 8. S.A. Theron ed altri, Multiple jets in electrospinning: experiment and modelling, Polymer, 46,
(2005) 2889-2899• 9. W. Tomaszewski et al., Investigation of electrospinning with use of a multi-jet electrospinning
head, Fibres & Textiles in Eastern Europe, October/December 2005, Vol.13 n. 4(52), 22-26• 10. A.L.Yarin et al., Upward needless electrospinning of multiple nanofibres, Polymer, 45 (2004),
2977-2980• 11. Elmarco, Brochure presentazione Sistema Nanospide®• 12. A. Varesano et al., Electrospinning and nanofibres in textile application, Nanonforum 2007,
Milan September 18-19th• 13. L. Li, et al., J. Eng. Fibers Fabrics, 1(1) (2006).• 14 T.H. Grafe, K.M. Graham, Nonwovens in Filtration Fifth International Conference, Stuttgart
(GER) 2003.
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Thank you very much for your attentionThank you very much for your attention
CONSIGLIO NAZIONALE DELLE RICERCHE
ISTITUTO PER LO STUDIO DELLE MACROMOLECOLE
Sede di BIELLA
C.so G. Pella 16, 13900 BiellaTel. +39-15-8493043 - Fax +39-15-8408387
e-mail: [email protected]
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