Aquisição de tempos de vida de fosforescência com resolução de fase e sua aplicação ao estudo de relaxações em polímeros

M. Talhavini, T. D. Z. Atvars
1998 Química Nova  
Recebido em 17/3/97; aceito em 9/8/97 PHOSPHORESCENCE LIFETIME IN POLYMER RELAXATION STUDIES: PHASE RESOLU-TION METHOD. We describe in this work a simple experimental set up to perform time dependent luminescence experiments in time scales from mili-seconds to seconds, based on the phase resolution of the emission signal. This system is composed by modulation of a continuous light source with an external chopper controlled by a lock-in amplifier. We exemplified the utility of the system in
more » ... the system in studies of phosphorecence emission using benzophenone dissolved in polystyrene and since the phosphorescence intensity and lifetime are temperature-dependent processes, we also studied polymer relaxation processes in the temperature range from 20 to 400K. A software that drives the spectrofluorimeter and controls both the cryosystem and the lock-in amplifier was developed.
doi:10.1590/s0100-40421998000300015 fatcat:kky2367qunetlanksmtbgdsd4y