1 Fyzikální principy tvorby nanovláken 1. Úvod D.Lukáš 2014

2 Physical principles of electrospinning (Electrospinning as a nano- scale technology of the twenty- first century) D. Lukáš; A. Sarkar; L. Martinová; K. Vodsed'álková; D. Lubasová; J. Chaloupek; P. Pokorný; P. Mikeš; J. Chvojka; M. Komárek Department of Nonwovens, Faculty of Textile Engineering, Technical University of Liberec, Liberec, Czech Republic Physical principles of electrospinning (Electrospinning as a nano-scale technology of the twenty-first century)

3

4 Chapters Physical principles of electrospinning (Electrospinning as a nano-scale technology of the twenty-first century) 1. Introduction 2. Historical overview 3. Theoretical evolution of electrospinning 4. Liquid jet in an electric field 5. Special collectors 6. Electrospinning variants 7. Exceptional features of electrospinning 8. Polymeric solutions for electrospinning 9. Základy teorie zvlákňování 10. Nanovlákna v buňce 11.Tvorba nanovláken technologií „drawing“, tažení 12.Tvorba nanovláken technologií odstředivého zvlákňování Přednášky podle učebnice Samostudium Pouze přednášky

5 Podmínky pro udělení zápočtu + další informace 100% účast na seminářích (krom dálkových studentů) Sledování obsahu přednášek a plnění úkolů z nich vyplývajících. Absolvování testů: v polovině semestru a testu zápočtového se známkou alespoň d o b ř e Odevzdání a „obhájení“ semestrální práce na téma: Centrifugální zvlákňování Výroba nanovláken technologií tažení Výroba nanovláken technologií MeltBlown Aplikace nanovláken (biologie,leštění …) Produkce nanovláken živočich (hmyz) nebo rostlinami Teorie zvlákňovacího procesu (Ziabinski) Výrobci zařízení pro elektrostatické zvlákňování

6 Ing. Julie Soukupová, Ing. Tomáš Kalous – představení Stanovení termínů seminářů/cvičení – seminární mástnost KNT Poskytnutí kontaktů na studenty – a mobil. david.lukas  tul.cz, Další informace

7 Monographs [1] Y. Filatov, A. Budyka, and V. Kirichenko, Electrospinning of micro- and nanofibres: fundamentals in separation and filtration processes, Begell House Inc., Redding, [2] S. Ramakrishna, K. Fujihara, W. Teo, T. Lim, and Z. Ma, An introduction to electrospinning and nanofibres, World Scientific Publishing Co., Singapor, [3] D.H. Reneker and H. Fong, Polymeric nanofibres, Oxford University Press, Washington D.C., [4] D.H. Reneker and A.L. Yarin, Electrospinning jets and polymer nanofibres, Polymer, 49 (2008), pp (INTERNET) [5] A.L. Andrady, Science and Technology of Polymer Nanofibres, Wiley, New Jersey, 2008.

8 Monographs Open Access Nanotechnology and Nanomaterials Nanofibers - Production, Properties and Functional Applications Edited by Tong Lin, ISBN , Hard cover, 458 pages, Publisher: InTech, Chapters published November 14, 2011 under CC BY 3.0 license Internet and-functional-applications

9 Electrospinning Force spinning Drawing Melt Blown Production of nanofibres by living cells, insects, e.t.c. Various methods to produce nanofibres

10 Figure Schematic diagram of an electrospinning set up: (1) syringe and metering pump (2) needle/capillary serving as the electrode (3) stable part of the jet, (4) whipping/coiling zone, (5) collector, (6) ground, (7) high voltage supply, Electrospinning and a needle electrospinner Video“ ww.youtube.co m/watch?v=87 uRQ7KwbB0

11 Drawing

12

13 Force spinning

14 Melt blown Ellison C. J. Melt blown nanofibers: Fiber diameter distributions Polymer and onset of fiber breakup 48 (2007) 3306e no/pluginfile.php/689/cou rse/section/777/1-s2.0- S main.pdf

15 Melt blown Fig. 3. Representative SEM images from (a) PS-1, (b) PS-3, (c) PP-1, (d) PP-3, (e) PBT-1, and (f) PBT-2 melt blowing runs. All black scale bars represent 2 mm.

16 Production of nanofibres by livig cells

Needle Electrospinning Solvent evaporation Whipping Taylor cone Stable jet 1 2 John Zeleny, Physical Review, Vol. III, No. 2, 1914 An easy technology - History

18 Electrospinning process has potential to revolutionise spinning technology.

19 Unlike a typical classic nonwoven technology the devices and equipments in electrospinning process are free of complex passive or rotating components. Carding machine Electrospinner An easy technology – complex phenomenon

20 Various physical phenomena play the role of traditional mechanical components when fibre spun under external electric field. So, the magnificence of mechanical engineering is substituted indirectly by external fields in helping in diverse physical self-organization. Hence, a better understanding of its intrinsic physical fundamentals is needed for further technological developments and, so, this lectures are largely devoted to the physical insight, in an attempt to enlighten the marvellous phenomenon of electrically driven polymeric jets. Better understanding of Electrospinning intrinsic physical fundamentals is needed

21 It has remarkable manifold external morphology: (2) ‘Roots’ evolving from a charged extremely thin surface layer, called as Debye’s layer, of the polymer solution. (3) Stable part of the jet that looks like a ‚tree stem‘. (4) Whipping zone / bending instability of the jet looks out like ‚branches‘ of the tree with lives of the form of jet coil cascades and jet-branching. (5) Eventually, the nanofibres collected on the other electrode, so-called collector, may literally be thought of as the ‘fruits’ of the entire process. Electrospun polymeric jet almost resembles a tree. Electrospinning jet

Physically, electrospinning is a consequence of a tug of war between electrostatic and capillary forces. Liquid bodies disintegrate due to long range repulsive Coulombic forces between ions of the same signs, Capillary forces causes liquid particles to flock together to minimize the liquid surface area and surface energy, resulting from short distance intermolecular interactions at quantum level. 22 Electrostatic and capillarity

23 Liquid bodies disintegrate in two possible ways: (1) Simple liquids, having small molecules, spray in clouds of small charged droplets with a tendency to break down further. (2) Polymer solutions and polymer melts with sufficiently entangled macromolecules disintegrate in long tiny liquid columns. The internal pressure of electric nature, forces them to be stretched longitudinally. Electrospinning and Electrospraying

24

25 Narrowing down of the jet effectively drives the solvent out from the jet. Solvent Thermodynamics governs a solvent evaporation

26 Whipping zone / bending instability of the jet Whipping zone

27 d =200 nm Polymer solution Self-organized nanofibrous layer s S Electrospinning resembles biological procedures wherein bio- nanofibres like cellulose and collagen are created by self-organization. Entropy Self-organization

28 Electrospinning technology can be divided into two branches. (1)Less productive needle / capillary spinners with production rates in the order of unit grams per hour. (2) Highly productive jet creation from free liquid surfaces by self-organization. These effective methods may be classified as needleless electrospinning. Needle and needleless Electrospinning technology

29 Magnified view of the coil; photos of spiral coil spinning processes. Needleless Electrospinning

30 Filip Sanetrník, TUL, Rod Electrospinning

31

32 The technologies to produce polymeric nanofibrous materials, are of primary interest of various disciplines, like: medicine, biology, tissue engineering, drug delivery systems, Chemical engineering, textile and material engineering, filtering, protective clothing, substrates for catalysis, analytical chemistry, testing probes. Applications

33 Domácí úkol 1: Nakreslete schéma jehlového a bezjehlového/hladinového způsobu elektrostatického zvlákňování a popište jeho jednotlivé součásti a „fáze“ polymerní trysky. Domácí úkol 2: Načrtněte časovou osu a zaznamenejte na ni významné události při vývoji teorie i technologie elektrostatického zvlákňování. Domácí úkol 3: Vyjmenujte známe metody/technologie pro výrobu nanovláken Domácí úkol 4: Uveďte alespoň 5 oblastí aplikace nanovlákenných materiálů.