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Plasma polymers formed in radio frequency sustained non-equilibrium plasma

Plasma polymers formed in radio frequency sustained non-equilibrium plasma. Morgan Alexander.

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Plasma polymers formed in radio frequency sustained non-equilibrium plasma

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  1. Plasma polymers formed in radio frequency sustained non-equilibrium plasma Morgan Alexander

  2. Different flame types of a Bunsen burner depend on oxygen supply. On the left a rich fuel mixture with no premixed oxygen produces a yellow sooty diffusion flame, and on the right a lean fully oxygen premixed flame produces no soot and the flame color bob produced by molecular radical band emission. The Earth's "plasma fountain", showing oxygen, helium, and hydrogen ions that gush into space from regions near the Earth's poles. The faint yellow area shown above the north pole represents gas lost from Earth into space; the green area is the aurora borealis-or plasma energy pouring back into the atmosphere. An example of a plasma displayComposition of plasma display panel Plasma A fluorescent lamp is a gas-discharge lamp that uses electricity to excite mercuryvapor in argon or neon gas, resulting in a plasma that produces short-wave ultraviolet light. This light then causes a phosphor to fluoresce, producing visible light.0

  3. Radio frequency sustained non-equilibrium plasma

  4. Plasma components • Electrons • Monomer • Radical monomer molecules and molecular and atomic fragments • Positive molecules • Negative molecules • Radiation, including visible and vacuum UV • Substrate-sheath

  5. Reactions of electrons Ionization e- + X-X → X-X+ + 2 e- e- + X → X+ + 2 e- Dissociative ionization e- + X-X → X+ + X+ + 2 e- Dissociation e- + X-X → 2X + e- Dissociative attachment e- + X-X → X- + X X- + X+ + e- Attachment e- + X-X → X-X- e- + X → X- Recombination e- + X+ → X e- + X-X+ → X-X Reactions of ions Charge transfer X+ + X-X → X-X+ + X X-X+ + X → X-X + X X- + X-X → X-X- + X X-X- + X → X-X + X- Detachment X- + X → X-X + e- X- + X-X → X-X + X + e- X-X- + X → X+X X-X + e- X-X- + X-X → 2 X-X + e- Ion-ion recombination X- + X+ → X-X X- + X-X+ → X-X+X X-X- + X+ → X-X + X X-X- + X-X+ → 2 X-X Atom recombination 2 X → X-X 3 X → X+ X-X X → WALL ½ X-X Examples of reactions which can occur in the plasma phase of a di-atomic gas A.T. Bell, Chapter 1 in: Techniques and Applications of Plasma Chemistry, Eds.: J.R. Hollahan and A.T. Bell, Johan Wiley, New York, (1974).

  6. Yasuda (1985)

  7. A new positive ion mechanism O'Toole, L.; Beck, A. J.; Ameen, A. P.; Jones, F. R.; Short, R. D., Radiofrequency-Induced Plasma Polymerization of Propenoic Acid and Propanoic Acid. Journal of the Chemical Society-Faraday Transactions 1995, 91, (21), 3907-3912.

  8. More positive ion mechanisms Alexander, M. R.; Jones, F. R.; Short, R. D., Mass spectral investigation of the radio-frequency plasma deposition of hexamethyldisiloxane. Journal of Physical Chemistry B 1997, 101, (18), 3614-3619.

  9. Surface MS (ToF SIMS)

  10. Experimental setup required to detect negative ions

  11. Peculiarities of PPs

  12. Summary • A large range of reactions are possible in plasma. • Initial plasma polymerisation mechanisms were speculative based on conventional chemistry. • Much subsequent work has sought to measure the species in organic plasmas, revealing other potential mechanisms. • Plasma polymers are often unstable due to a high concentration of trapped free radicals. [T Gengenback ]

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