Title: Photoisomerization of a carbocyanine derivative in the reverse phases of a block copolymer: Evidence for the existence of water droplets
Authors: Mali, Kunal
Dutt, G. B ×
Mukherjee, T #
Issue Date: Aug-2006
Publisher: Amer chemical soc
Series Title: Langmuir vol:22 issue:16 pages:6837-6842
Abstract: In an attempt to understand the nature of water present in the reverse phases of aggregates formed with the triblock copolymer poly(ethylene oxide)(20)-poly(propylene oxide)(70)-poly(ethylene oxide)(20) (P123) and also investigate how these confined environments influence the rates of photoisomerization, fluorescence lifetimes and quantum yields of a carbocyanine derivatives-3,3'-diethyloxadicarbocyanine iodide (DODCI)-were measured in these systems over the temperature range of 293-318 K. Three different copolymer-oil-water compositions were chosen such that the mole ratio of water to copolymer (W) spans the range of 50-150. In these systems, butyl acetate was used as the oil or the nonpolar component. It has been noticed that in all three systems the fluorescence decays of DODCI comprise a long component whose contribution is 85-90%, and this has been ascribed to the fraction of solute solubilized in the core region where hydrated poly(ethylene oxide) units are present. A short-decay component is associated with the remaining fraction, and its values match with those measured in water, indicating that the water present in these reverse phases is in the form of droplets. The photoisomerization rate constants of DODCI located in the core regions of the reverse phases are identical in the three systems at a given temperature and similar to the ones obtained in normal phases of P123. The reasons for the observed behavior have been discussed.
ISSN: 0743-7463
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Molecular Imaging and Photonics
× corresponding author
# (joint) last author

Files in This Item:

There are no files associated with this item.

Request a copy


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science