Electrospun nanofibrous materials as X-ray sources at atmospheric conditions Pavel Pokorný, Petr Mikeš and David Lukáš 1Electrospinning - X-rays

2 Technical University of Liberec Czech Republic

Clemson UniversityElectrospinning - X-rays3 William Gilbert 1600 amberHistory

Clemson UniversityElectrospinning - X-rays4 Solvent evaporation Whipping Taylor cone Stable jet d =200 nm Polymer solution Self-organized nanofibrous layerSelf-organization John Zeleny ( ) Czech-American physicist

5 Epoxy resin E no Self-organization E = 0 E = E c EcEcEcEc A rode instead of a needle 5 d=1cm Stationary wave F.Sanetrník Sandra Torres

Clemson UniversityElectrospinning - X-rays6 Technology Jirsák, O. Sanetrník, F. Lukáš, D. Kotek, V. Marinová, L. Chaloupek, J. (2005) WO A Method of Nanofibres Production from A Polymer Solution Using Electrostatic Spinning and A Device for Carrying out The Method.

Clemson UniversityElectrospinning - X-rays7 Capillary force Elektrostatic force Force equilibrium ! r h  Physics Sir G. Taylor (1964) Disintegration of water drops in an electric field, Proc. Roy. Soc. A, vol. 280, 1964, pp Needle Electrospinning permitivity

Clemson UniversityElectrospinning - X-rays8 Wave vector Angular frequency Physics Needleless electrospinning Dynamic phenomenon: field strength increment can lead to unlimited growth of a wave amplitude. A. Sarkar Growth factor Amplitude

Clemson UniversityElectrospinning - X-rays9 Stable amplitude Growing amplitude Physics Lukas D Sarkar A Pokorny P, S ELF ORGANIZATION OF JETS IN ELECTROSPINNING FROM FREE LIQUID SURFACE - A GENERALIZED APPROACH, ACCEPTED FOR PUBLICATION, Journal of Applied Physics, 103 (2008), Dispersion law

Clemson UniversityElectrospinning - X-rays10 Stable waves of various wave numbers and angular frequencies. Fastest forming instability The only wave Physics Various field strengths E E Tonks-Frenkel instability

Clemson UniversityElectrospinning - X-rays11 Experimental 

Clemson UniversityElectrospinning - X-rays12 Linear clefts emit polymeric jets. Linear clefts in (a) and (b) emit polymeric (polyvinyl alcohol) jets at the voltages, 32 kV and 43 kV, respectively. The inter-jet distance / wavelength is. The distance between the cleft and the collector was adjusted on 802 mm. b 32 kV43 kV Experimental

13Clemson UniversityElectrospinning - X-rays Electrospun nanofibrous materials as X-ray sources

+ + Clemson University14 St. Elmo‘s fire

D.H. Reneker, A.L. Yarin / Polymer 49 (2008) Taylor coun

First observation of radiation recorded in X-ray sensitive film. 16 Shield: -black paper, 160 g/m -2 -Aluminum foil, 0.01 mm, 25 gm -2. Deutherium lamp HERAEUS D200F, 300W, UV light,160 nm- 400 nm, i.e. 120 eV - 50 eV, Clemson UniversityElectrospinning - X-rays P. Pokorný observation

Electrospinning setup Setup with parallel and fixed gold- coated nanofibers X-ray record SEM microphotograph Clemson University Experimental setup

The detected radiation arose from the vicinity of freshly electrospun nanofibres as proven by the geometrical similarity of the tracks recorded on a radiographic film and the location of deposited nanofibrous heaps. 18 X-ray records

19Clemson University X-ray records Kirlian photography

-Premium performance spectroscopy from 1 keV to 30 keV -Energy resolution 35 eV -Thin Be window, 25  m -Nitrogen cooled Prof. Tomáš Čechák FJFI, ČVUT – Prague 20Clemson UniversityElectrospinning - X-rays SLP Silicon Lithium-Drifted Low-Energy X-Ray Detector

21 Electromagnetic spectrum of radiation

22 Continuious ‘bremsstrahlung’ and Discrete ‘characteristic radiation’

Spectra 23 Continuious ‘bremsstrahlung’ and Discrete ‘characteristic radiation’

24 Richard P. Feynman: „There‘s plenty of room at the bottom.“ (1959) teraT10 12 gigaG10 9 megaM10 6 kilok10 3 prefix X-ray sources at atmospheric conditions

25 MACRO NANO Clemson UniversityElectrospinning - X-rays Macro and nano … NANO h = 10 cm a = 50 nm

26Clemson UniversityElectrospinning - X-rays Warp of fibers

8 x 10 8 m -3 Clemson University27Electrospinning - X-rays Ionic clouds, Debye length, Manning region, Counterion condensation Poisson–Boltzmann equation

- + Kornev K. Lateral interactions of charges in thin liquid films and the Berezinskii-Kosterlitz-T houless transitiv, Physical Review E, 60 (4), (1999). 28 Manning region

29 Needleless electrospinning is promising industrial technology. It will be worthwhile to investigate x-ray emission from nanofibrous electrodes in a more intensive manner, since it could find applications in a lot of fields. Clemson UniversityElectrospinning - X-rays Conclusion

Clemson UniversityElectrospinning - X-rays30 Antonín Kopal Konstantin Kornev Acknowledgement

Thank you for your attention. You are more than welcome to an open discussion. 31

Radon daughter deposition on electrostatically charged surfaces Background level Measurement by Geiger – Muller detectror Radiant energy ranges of Gamma-radiation: from 0,06 to 1,2 MeV Radiant energy ranges of Beta-radiation: from 0,5 to 3 MeV 32Clemson UniversityElectrospinning - X-rays

33 Lily Nanofibres

Clemson UniversityElectrospinning - X-rays34 W.J. Morton: Method of dispersing fluids, US Patent, Seriál No. 705,691, July 29, 1902 (Application 1900) „Electrical method where volatile fluids are separated from their combination or association with relatively non-volatile or fixed substances in composite fluids.“History Needleless Electrospinning

Clemson UniversityElectrospinning - X-rays35 John Zeleny ( ) was a Czech-American physicist at the University of Minnesota. CzechAmerican physicist University of Minnesota CzechAmerican physicist University of Minnesota His work is seen by some as a beginning to emergent technologies like liquid metal ion sources and electrospraying and electrospinning. electrospraying electrospinning electrospraying electrospinningHistory Needle Electrospinning

Clemson UniversityElectrospinning - X-rays36 Technology Theron, Yarin, Zussman (2005) Polymer, 46 Needle arrays Scaling up the technology 1 g/hour

Clemson UniversityElectrospinning - X-rays37 Yarin, Zussman (2004) Polymer, 34 Needleless Electrospinning Technology

Clemson UniversityElectrospinning - X-rays38 Needleless Electrospinning Bubble Electrospinning Yong Liu, Ji-Huan He International Journal of Nonlinear Sciences and Numerical Simulation, 8(3),2007

Clemson UniversityElectrospinning - X-rays39 Stable amplitude Growing amplitude Growing parameter  is imaginary Physics

Clemson UniversityElectrospinning - X-rays40 Euler equation Landau equation gravitation Surface tension Elektrostatic forces Physics dispersion law Velocity potential

Clemson UniversityElectrospinning - X-rays41 Critical field strength for needle electrospinner. Experimental 2r J. Zeleny, Phys. Rev. 3 (1914), p. 69

Clemson UniversityElectrospinning - X-rays42 Experimental Cleft spinner

Clemson UniversityElectrospinning - X-rays43 Rayleigh instability rr0rr0 Physics

Clemson UniversityElectrospinning - X-rays44 32 kV Experimental

Clemson UniversityElectrospinning - X-rays45 42 kV 'Physical principles of electrospinning (Electrospinning as a nano-scale technology of the twentyfirst century)',Textile Progress,41:2, , (2009). Experimental 1 cm

46 Polystyrene Density =1.060E+00 (g/cm 3 ) Energy t 1/2 Energy t 1/2 (keV) (cm 2 /g) (mm) E E+03 0, E E+01 0, E E+00 4, E E-01 21,622 Clemson UniversityElectrospinning - X-rays

47 Air, Dry (Near Sea Level) Density= 1.205E-03 (g/cm 3 ) Energy t 1/e Energy t 1/e (keV) (cm 2 /g) (mm) E+03 2, E+03 2, E+01 24, E+01 24, E , E ,051 The mass attenuation coefficient, Clemson UniversityElectrospinning - X-rays X- ray attenuation

Clemson UniversityElectrospinning - X-rays48 Kirlian photography: If an object on a photographic plate is connected to a source of high voltage, small corona discharges (created by the strong electric field at the edges of the object) create an image on the photographic plate.photographic platecorona dischargeselectric field Kirlian Photography

h = m a = m 49 Single fiber

50 The X-ray radiation

51Clemson University Crookes tubesCrookes tubes: invented by British physicist William Crookes and others in1920s. William Crookes tubesWilliam Crookes X- ray tube