Abstract
Ultrafast time-resolved UV-visible absorption spectroscopy has been used to study four model azo dyes and five commercial azo dyes. All of the dyes have been found to show strong bleaching of their ground-state absorption bands on photoexcitation, with recovery lifetimes of 1-5 ps in aqueous solution that are attributed to rapid and efficient non-radiative decay; two commercial azo dyes deposited in cellophane have been found to show an additional longer-lived component with a lifetime of > 50 ps that is attributed to the effects of intermolecular interactions with the cellulosic environment. (C) 2011 Elsevier B.V. All rights reserved.
Original language | English |
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Pages (from-to) | 11-16 |
Number of pages | 6 |
Journal | JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY |
Volume | 218 |
Issue number | 1 |
DOIs | |
Publication status | Published - 5 Feb 2011 |
Keywords
- Azo dye
- Picosecond
- Time-resolved UV-visible spectroscopy
- Cellulose
- Cellophane
- VISIBLE ABSORPTION-SPECTROSCOPY
- ALPHA-HYDROXYALKYL RADICALS
- QUANTITATIVE RATE CONSTANTS
- LASER FLASH-PHOTOLYSIS
- TRANS-AZOBENZENE
- ORANGE-II
- AQUEOUS-SOLUTION
- PULSE-RADIOLYSIS
- SPECTRAL CHARACTERIZATION
- OXIDIZED FORMS