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

Autor:	Talhavini, M., Atvars, T. D. Z.
Jazyk:	portugalština
Rok vydání:	1998
Předmět:	polymer relaxation processes phase resolution lifetime determinations benzophenone
Zdroj:	Química Nova v.21 n.3 1998 Química Nova Sociedade Brasileira de Química (SBQ) instacron:SBQ Química Nova, Volume: 21, Issue: 3, Pages: 332-336, Published: JUN 1998
Popis:	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 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.
Databáze:	OpenAIRE
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