Laser flash photolysis of dyed fabrics and polymers—I. Rose bengal as a photosensitizing dye
✍ Scribed by F. Wilkinson; C.J. Willsher; R.B. Pritchard
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- English
- Weight
- 512 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0014-3057
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✦ Synopsis
A~tract---We report emission and transient absorption observed using diffuse reflectance following pulsed laser excitation of rose bengal in a variety of opaque heterogeneous environments. These include kinetic transient absorption studies for the first time on dyed fabrics and within cross-linked polymer beads to which rose bengal has been chemically attached. The transient absorption difference spectra which sometime show ground state depletion and isosbestic points upon decay are assigned to the production of triplet rose bengal. The transient decay is a mixture of first and second order kinetic processes. A strong contribution due to triplet-triplet annihilation is interesting in connection with the possibility of energy transfer between dyes attached to or adsorbed on polymers. These measurements illustrate that the primary photochemical processes of heterogeneous sensitizers and dyed fabrics can now be studied directly using diffuse reflectance flash photolysis.