Abstract: | The spectra of transients produced in pulse-irradiated pure poly(methyl methacrylate), PMMA, at room and ∼ 130 K temperatures were measured. The intermediates were identified as PMMA radicals and radical anions. In the pulse-irradiated PMMA–pyrene (Py) system the solute excited states and radical ions were produced. Scavenging of negative charges by Py was directly observed at 130 K in a µs time scale. Py fluorescence was found to be produced mainly as a result of Čerenkov photoexcitation. At room temperature, some contribution of ionic mechanism to Py fluorescence formation was found. © 1997 John Wiley & Sons, Inc. |