Electrospinning process and its application in the textile field

Transcription

1 CNR ISMAC Istituto per lo Studio delle Macromolecole Sede di Biella Electrospinning process and its application in the textile field Electrospinning research group A. Varesano G. Mazzuchetti A. Aluigi C. Vineis 1

2 now-how 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 2

3 Electrospinning process Polymer filaments using a electrostatic force Formahls Electrodes 3

4 Application areas her Areas: ctromagnetic interference shielding D and photovoltaic devices tra-lightweight spacecraft materials 25% Medical and Life Science: Natural extra-cellular matrix Porous membrane for skin Tubular shapes for blood vessels and nerve regeneration Three dimensional scaffolds for bone and cartilage regeneration Drug delivery carrier Wound dressing 60% 15% Filter media: Liquid filtration Gas filtration Molecule filtration 4

5 Applications in textile field Thermal insulation Vapour resistance Lightness End use performance Comfort Leisure Nanofibres properties: Large surface-to-volume ratio High effective porosity Small pore size Low apparent density High surface cohesion Sportswear Protective cloths chemical and biological gas Anti vapour barriers Bacteria barrier Comfort High durability and easy filter cleaning High efficiency Trapping of tiny unfriendly particles with diameter < 0,5 µm Media filters 5

6 Electrospinning device for polymer solution CNR ISMAC Biella Electric field Schematic of the electrospinning setup Characteristics electrospinning device High - voltage power supply: 0-30 kv Metering pump: ml/h Metallic needle: mmø Collector (rotanting) : 5.5 cmø 6

7 undamental aspect electrospinning process REF > ST 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 Emisferical surface of the fluid at the tip of the capillary tube Increasing the electric field intensity the emisferical surface elongates a conical shape Taylor cone Electrospun mat: final product Electrospun nano-fibres web: a typical random distribution of the nano fibres on the collector The polymers solution, during the course from the tip of the capillary tube to the collector, undergoes whipping process where the solvent evaporation occurs 60 fps Linear Fluid-dynamic instability zone Jet trajectory Typical whi like motion 5000x 4500 fps 7

8 Electrospinning parameters Process Parameters System parameter Solution properties Molecular weight Polymer architecture Flow rate of the polymer solution Electrical potential at the capillary tip Concentration Conductivity Hydrostatic pressure in the capillary tube Gap distance between the tip an the collector Viscosity Surface tension Temperature Pressure Ambient conditions

9 System and processes parameters: influence on fibres diameters and defects 1/2 Parameters viscosity solution polymers concentration surface tension gap electrodes distance electrical voltage Beads Fibres diameters Defects /Beads

10 System and processes parameters: influence on fibres diameters, defects and morphology 2/2 Droplets 1 Beads Droplet Polymer molecular weight Beads Drops 2 Solvent volatility 3 Nanofibres with pores Diameter Flow rate Beads 250 nm From Zheng-Ming Huang et al., Composite Science and Technology, 63 (2003), nm 10

11 bres diameter [nm] vs. Electrical Voltage [kv] 20000x PEO/ Water, 5% p/p 15 kv, 0.01 ml/min d m = 251 nm PEO/ Water, 5% p/p, Diameters distribution Diameters distribution nm 20 kv, 0.01 ml/min 20000x d m = 190 nm Diameters distribution nm PEO/Water, 5% p/p, kv, 0.01 ml/min 30 kv d m = 172 nm nm

12 Electrospinning device for polymer melt Polypropylene electrospun condition: T 1 : 230 C T 2 : C T 3 : C T 4 : C Seungsin Lee et al., Developing protective textile materials as barriers to liquid penetration using melt electrospinnig, Journal of applied polymer science, vol.102, (2006) 12

13 Filtration 1/3 Filtration Mechanisms Mechanical separation Coarse Particles Inertial impact Particles > 0,5 µm Diffusion Particles < 0.5 µm Adsorption Nanofibres!! 13

14 Filtration 2/3 Front view Electrospinning process: PEO nanofibre deposition Front view Cross-section PET non-woven ir permeability: 2510 m/h Collector PET non-woven + nanofibres web PET non-woven Performance request to filter media Trapping of tiny unfriendly particles with diameter < 0,5 µm High efficiency High durability and easy filter cleaning Trapping of tiny unfriendly particles with diameter < 0,5 µm Pz = f(d*t -1 ) Pz = pore size d = fibre diameter t = exposition time From F. Dotti, A. Varesano, A. Montarsolo, A. Aluigi, C. Tonin, G. Mazzuchetti, J. Ind. Textiles, 37, 2/ October 2007,

15 iltration 3/3 High efficienty PA6 nanofibres on cellulose-based air filter Use the nanofibers filter resulted 4 times less penetration of sub-micron dust Filter Outside dust [mg/m 3 ] Inside dust [mg/m 3 ] Dust reduction% Cellulose Sub-micron Respirable >1 micron Cellulose +nanofibers Sub-micron Respirable >1 micron From L. Li, et al., J. Eng. Fibers Fabrics, 1(1) (2006). (Available on: From T.H. Grafe, K.M. Graham, Nonwovens in Filtration Fifth International Conference, Stuttgart (GER) Filtration efficiency is improved by nanofibre webs. Filtration efficiency increases as coverage level increases Similar life with nanofiber filter and standard filter 15

16 rotective cloths 1/2 PET non-woven Air permeability: 2510 m/h Barrier performance Good breathability Comfort Good water vapour diffusion Barrier performance but From F. Dotti, A. Varesano, A. Montarsolo, A. Aluigi, C. Tonin, G. Mazzuchetti, J. Ind. Textiles, 37, 2/ October 2007, Air permeability: f(d*s -1 ) Air permeability Goal High protection as well as an acceptable level of comfort Comfort 16

17 rotective cloths 2/2 Nonwoven + microporous membrane Nonwoven + electrospun membrane Electrospun membrane: A good compromise among protection and comfort Air p ermeab ity [cm 3 /s/cm 2 ] microporous membrane electrospun membrane woven work cloth Protection % 17

18 roblems connected to electrospinning pplication in textile field Productivity: Electrospinning feeding: from polymer solution? multi jet solution? from polymer melt? other systems? 18

19 roductivity 1/3 Multi jet device Mono jet: from 10 µl/min to 10 ml/min Multi jet* : from 22.5 µl/cm 2 min to 22.5 ml/cm 2 min *inter capillary distance: 1 cm density: 2 capillaries/cm 2 Jets pushed away from their neighbours by Coulombic forces applied from the latter From S.A. Theron et al., Multiple jets in electrospinning: experiment and modelling, Polymer, 46, (2005)

20 roductivity 2/3 Needleless electrospinning = layer of magnetic liquid ; = layer of polymeric solution; e d = counter electrode located at a distance H; = high voltage source; = electromagnet From A.L.Yarin et al., Upward needless electrospinning of multiple nanofibres, Polymer, 45 (2004),

21 roductivity 3/3 Needleless electrospinning: Elmarco Nanospider 21

22 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 22

23 Electrospinning research activities on the textile field Process Product Feeding system Collectors for electrospun fibres Physical and Mechanical performance Cross-linking nanofibre web on textile support 23

24 ibliography 1. M. Ming Huang et al., A rewiew on polymer nanofibers by electrospinning and their application in nanocomposites, Composites Science and Technology, 63, A. Montarsolo et al., Potenzialità e Applicazioni delle Nanofibre prodotte mediante Elettrofilatura per l Innovazione Tessile, Convegno NanoItaltex Milano 12 luglio G. Mazzuchetti et al, Relazione finale Progetto LATT, Regione Piemonte 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, settembre Padova 5. Defil, La filtrazione dell aria, 6. F. Dotti et al. Electrospun porous mats for air/gas filtration, Journal of industrial textiles, 37, 2007, Seungsin Lee et al., Developing protective textile materials as barriers to liquid penetration using melt electrospinnig, Journal of applied polymer science, vol.102, (2006) 8. S.A. Theron ed altri, Multiple jets in electrospinning: experiment and modelling, Polymer, 46, (2005) 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), A.L.Yarin et al., Upward needless electrospinning of multiple nanofibres, Polymer, 45 (2004), 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)

25 CONSIGLIO NAZIONALE DELLE RICERCHE ISTITUTO PER LO STUDIO DELLE MACROMOLECOLE Sede di BIELLA C.so G. Pella 16, Biella Tel Fax segreteria@bi.ismac.cnr.it Thank you very much for your attention 25