Long‐lived species generated via irradiation of poly(methyl methacrylate) containing pyrene

Abstract

The fate of long‐lived species [pyrene (Py) radical cations and Py–cyclohexadienyl‐type radicals] generated by electron‐beam irradiation at room temperature in poly(methyl methacrylate) (PMMA) doped with Py is described. The separation of reacting solute intermediates and the relaxation phenomena seem to be the main factors limiting the reactivity of long‐lived Py species in the PMMA matrix. The temperature‐stimulated recombination of ionic species in PMMA doped with Py results in Py excited‐state formation. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4110–4118, 2001

Wavelength-selected radiothermoluminescence of polyethylene doped with pyrene

“…For the highest Py concentration, a very broad and strong WS RTL 395 maximum was found in the temperature range of 100–160 K. For such Py concentration all e have to be scavenged by solute, and no e are present in the PE matrix; hence, this WS RTL 395 peak has to be related to molecular solute radical ion recombination also. In the temperature range lower than the glass transition, the tunnelling mechanism should be involved in the charge transfer because of rather low activation energy found for the Py radical ion recombination reaction by means of the pulse radiolysis method 7, 13. The migration of Renker‐type defects in crystalline PE has been suggested to occur at about 123 ± 5 K,9 and may influence the events on the lateral surfaces of crystalline domains interacting in this way with amorphous regions.…”