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Stretching and Instabilities of Polymer Threads: A Comprehensive Overview

Explore the fascinating world of polymer thread formation and instability. Learn about the characteristics of flexible polymers, extension rates, stress-extension relationships, and the role of various factors in creating singularities. Discover insights from notable experiments and researchers in the field of polymer physics.

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Stretching and Instabilities of Polymer Threads: A Comprehensive Overview

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  1. Jens Eggers Polymer threads: formation and instability

  2. Drop breakup water drop …creates extensional flow and produces multiple singularities

  3. Flexible polymers • extension rate • stress ~ extension • characteristic time λ • maximal extension

  4. Wagner + Sattler Polymers water 50 ppm PEO in water 1.2mm, T = 0,1 sec Y. Amarouchene et al. PRL 86, 3558 (2001)

  5. Polymer breakup: overview polymer (Ch. Clasen) beads on a string blistering water jet

  6. Newtonian breakup: linear stability surface tension- inertial balance: W. Strutt fastest growing mode: (1873)

  7. Newtonian breakup: similarity solution glycerol drop center experiment by Tomasz Kowalewski 1mm Eggers, PRL `93

  8. Bead formation PEO in water Wagner et al., PRL ‘05 pure water

  9. One-dimensional approximation stretching Entov et al. `80 Renardy `82

  10. Thread formation thinning dominated by end effects! Bazilevskii et al, `81: Ch. Clasen and G. McKinley

  11. Corner region string tension: similarity solution thread drop Clasen et al., JFM ‘06

  12. Experiment: rescale thread similarity form: drop Boger fluid …but experimental curvature greater x 2 Clasen et al. JFM ‘06

  13. Blistering instability Sattler et al., PRL ‘08 increases by 5 orders of magnitude! full strech Fontelos + Li: Rayleigh instability with effective PEO in water, 2000 ppm

  14. Rayleigh instability? sub-pixel resolution! time (ms)

  15. Nonlinear instabilities • Iterated thread instability • (bulk) 2) Breathing instability (end)

  16. Weird instabilities

  17. Does it ever break? drops do not wet the fiber! PEO, 4Mio MW, 2kppm, overall duration 0.016s

  18. A solid fiber!

  19. Mayonnaise, ketchup, yoghurt movies by D. Bonn

  20. Remarks, open problems • No predictive model for flow at high deformations! • FENE-P: have to be treated as adjustable • thinning rate of filament depends significantly on concentration (factor 10), and even on nozzle radius! • no significant quantitative statement about saturation! • filament thinning still open (stability, full 3D model) • mechanism for demixing ???! • extensional behavior of suspensions; is there • extensional thinning?

  21. Polymeric fluid (100 ppm of PEO) experiment 1-D simulation Wagner, Amarouchene, Bonn, Eggers: PRL (`05)

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