Characterization of trapped electrons in .gamma.-irradiated hydrocarbon polymers by electron spin resonance and optical absorption spectroscopy

1969 ◽  
Vol 73 (5) ◽  
pp. 1623-1624 ◽  
Author(s):  
Ronald M. Keyser ◽  
Ffrancon Williams
Keyword(s):  
Electron Spin Resonance ◽  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Electron Spin ◽  
Optical Absorption Spectroscopy ◽  
Trapped Electrons ◽  
Spin Resonance ◽  
Hydrocarbon Polymers ◽  
Gamma Irradiated

Detection of trapped electrons in organic glasses after gamma irradiation at 4.2 °K by electron spin resonance spectroscopy

1967 ◽  
Vol 45 (22) ◽  
pp. 2723-2727 ◽  
Author(s):  
D. R. Smith ◽  
J. J. Pieroni
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Dipole Interaction ◽  
Necessary Condition ◽  
Resonance Spectroscopy ◽  
Hydrogen Atoms ◽  
Trapped Electrons ◽  
Organic Glasses ◽  
Spin Resonance ◽  
Gamma Irradiated

Several organic glasses which are known to form trapped electrons when gamma irradiated at 77 °K have been irradiated at 4.2 °K and examined by electron spin resonance (e.s.r.) at the same temperature. In each case an absorption is observed which is probably due to trapped electrons. In three cases, the yield of trapped electrons at 4.2 °K seems to be as great as at 77 °K. In one case, a glassy alkane, the yield is enhanced at 4.2 °K. Trapped electrons in ethanol give a narrower e.s.r. line at 4.2 °K than at 77 °K, suggesting less orientation in the solvent cage.Trapped hydrogen atoms are not detected after irradiation at 4.2 °K. Contrary to prediction, hydrogen atoms are also not detected after post-irradiation photolysis of the trapped electrons.The results suggest that electron traps exist prior to irradiation and that molecular orientation via electronic dipole interaction is not a necessary condition for electron trapping. The results do not distinguish between trapping in solvent defects or trapping via electron-induced polarization of molecular orbitals.

A photoconductivity study in γ-irradiated polyethylene at 77 K

1986 ◽  
Vol 64 (4) ◽  
pp. 695-701
Author(s):  
Toyoaki Kimura ◽  
Yutaka Ueda ◽  
Yohichi Hirai
Keyword(s):  
Electron Spin Resonance ◽  
Optical Absorption ◽  
Electron Spin ◽  
High Density Polyethylene ◽  
Methylene Chloride ◽  
Visible Region ◽  
Trapped Electrons ◽  
Photocurrent Generation ◽  
Spin Resonance ◽  
Absorption Measurements

A photoconductivity study was made on γ-irradiated low and high density polyethylene using 3-methylpentane, methylene chloride, and hexafluorobenzene as dopants. Electron spin resonance (esr) and optical absorption measurements were made together with photoconductivity. A study was also made for poly(4-methylpentene-1). The process of photocurrent generation is not ascribed totally to photodetrapping of trapped electrons in polyethylene; the process by photodetrapping of trapped electrons dominantly contributes to photocurrent generation in the ir region and may partly contribute in the visible region but not in the uv region. Another process for photocurrent generation other than photodetrapping of trapped electrons exists in the uv and perhaps partly in the visible region. We have tentatively ascribed this process to photodetachent of electrons from carbanions whch are formed by the reaction between radicals and electrons.

Electron spin resonance studies of radiation damage. Part IV. The effect of photobleaching on the trapped radicals in gamma irradiated 2-methyltetrahydrofuran glasses at 77 °K

1970 ◽  
Vol 48 (21) ◽  
pp. 3453-3455 ◽  
Author(s):  
F. P. Sargent
Keyword(s):  
Electron Spin Resonance ◽  
Radiation Damage ◽  
Electron Spin ◽  
Trapped Electrons ◽  
Spin Resonance ◽  
Gamma Irradiated

The concentration of trapped radicals was found to decrease during the course of photobleaching trapped electrons in gamma irradiated 2-methyltetrahydrofuran glasses at 77 °K.

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