Luminescence from Aromatic Polymers, Monomers, and Dimers under High-Energy Electron Excitation

Abstract

The luminescence spectra of various polymers and solid-model compounds induced by 1-MeV electrons are reported and interpreted. The presence of enhanced triplet emission and absence of singlet emission from poly(p-xylene), poly(monochloro-p-xylene), and the model compound dibenzyl are interpreted on the basis of a molecular resonance model. Some triplet excimer and other long-wavelength (450–550-mμ) emission were also observed in these spectra. The spectra of the monomers p-xylene and 2-chloro-p-xylene consisted primarily of long-wavelength emission (400–600 mμ), while the spectra of frozen toluene and durene exhibited both neutral molecule singlet and the long-wavelength emission. Benzene exhibited only singlet, singlet excimer, triplet, and triplet excimer emission. The polymers poly(ethylene-2,6-naphthalene-dicarboxylate), poly(ethyleneterephthalate), and polysulfone emitted primarily from singlet and singlet excimer states. The model compounds for these polymers, dimethyl-2,6-naphthalenedicarboxylate, dimethylterephthalate, and methyl-p-toluenesulfonate exhibited varying amounts of singlet, triplet, excimer, and neutral or ionic radical emission.

Investigation of transient species in pulse-irradiated poly(ethylene terephthalate) film

“…14 -26 The monomer compound, DMT, excited by an electron, produced at 300 K an emission 27 quite similar to that one observed by us. Isothermal luminescence spectrum detected at 83 K for PET irradiated by an electron beam at the same temperature was found to be constructed of two bands with maxima at 350 and 475 nm.…”

Ultra-Violet Light Emission from HPV-G Cells Irradiated with Low Let Radiation from 90Y; Consequences for Radiation Induced Bystander Effects

“…Light emission from polymers as a consequence of β particle and other ionizing radiations is not a new phenomenon and has been studied, generally for the purposes of radiation detection (Phillips andSchug 1969, Chen et al 2011). It is, of course, the physical basis of many scintillation radiation detector systems.…”

Features of fluorescence spectra of polyethylene 2,6‐naphthalate films

“…As films, these polyesters are endowed with excellent practical properties; therefore, their comparison has attracted much scientific and technological attention 2, 3. They are transparent in the visible region but absorb light strongly in the ultraviolet region, in which the absorption and emission spectra extend toward longer wavelengths in PEN than in PET 2, 4. The electron‐beam‐excited fluorescence of PET and PEN was first observed by Phillips and Schug,4 who attributed the main broad fluorescence band of a PEN film peaking around 430 nm to excimers.…”

“…They are transparent in the visible region but absorb light strongly in the ultraviolet region, in which the absorption and emission spectra extend toward longer wavelengths in PEN than in PET 2, 4. The electron‐beam‐excited fluorescence of PET and PEN was first observed by Phillips and Schug,4 who attributed the main broad fluorescence band of a PEN film peaking around 430 nm to excimers. Thermally stimulated chemiluminescence was observed in PEN when it was heated to 80–140°C 5.…”