M.Paula Militello , Micaela E. Grassano , Ernesto M. Arbeloa , Sonia G. Bertolotti , Carlos M. Previtali
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引用次数: 0
Abstract
The photopolymerization of acrylamide in water under visible irradiation was initiated by the system eosin B/triethanolamine in deaerated conditions. In order to understand the mechanism of photoinitiation, the photophysics of the dye in the absence and presence of the amine was studied. The absorption and fluorescence properties in ethanol–water mixtures were determined. The fluorescence quantum yields were 0.003 and 0.02 in water and ethanol, respectively. The triplet state was observed by laser flash photolysis only in the alcohol. In water, the transient signal could not be detected. The triplet quantum yield was estimated at 0.08. In the absence of the amine or in air equilibrated solutions the polymer was not formed. Since no triplet is detected by laser flash photolysis in water, the question regarding the photoinitiation mechanism arises. It is suggested that, despite the lack of transient signal with our laser photolysis system, the triplet is formed in very low yield. Since the dye is photostable under the irradiation conditions of the polymerization experiments, in the long term polymerization could take place initiated by the triplet.
期刊介绍:
JPPA publishes the results of fundamental studies on all aspects of chemical phenomena induced by interactions between light and molecules/matter of all kinds.
All systems capable of being described at the molecular or integrated multimolecular level are appropriate for the journal. This includes all molecular chemical species as well as biomolecular, supramolecular, polymer and other macromolecular systems, as well as solid state photochemistry. In addition, the journal publishes studies of semiconductor and other photoactive organic and inorganic materials, photocatalysis (organic, inorganic, supramolecular and superconductor).
The scope includes condensed and gas phase photochemistry, as well as synchrotron radiation chemistry. A broad range of processes and techniques in photochemistry are covered such as light induced energy, electron and proton transfer; nonlinear photochemical behavior; mechanistic investigation of photochemical reactions and identification of the products of photochemical reactions; quantum yield determinations and measurements of rate constants for primary and secondary photochemical processes; steady-state and time-resolved emission, ultrafast spectroscopic methods, single molecule spectroscopy, time resolved X-ray diffraction, luminescence microscopy, and scattering spectroscopy applied to photochemistry. Papers in emerging and applied areas such as luminescent sensors, electroluminescence, solar energy conversion, atmospheric photochemistry, environmental remediation, and related photocatalytic chemistry are also welcome.