Influence of the conformational state of polymethacrylic acid on the photophysical properties of pyrene in aqueous solution: a fluorescent probe and laser photolysis study
The excited state of pyrene observed in fluorescence and pulsed laser techniques is used to show that pyrene is solubilized in the polymer coil of aqueous solution of polymethacrylic acid (PMA) at pH < 4-5. This leads to a decreased access of molecules such as I/sup -/, Tl/sup +/, CH/sub 3/NO/sub 2/, and O/sub 2/ to excited pyrene in the polymer coil. The protection of the excited state by solubilization in the polymer is sufficient to enable 3-bromopyrene phosphorescence to be observed at room temperature in these systems. Increasing the pH of the system uncoils the polymer and leads to increased accessibility of excited pyrene to CH/sub 3/NO/sub 2/; eventually, at pH > 5, the pyrene is ejected into the aqueous phase of the system. In the presence of micellar solutions of surfactants increasing pH transports the pyrene from the polymer to the micellar aggregates. These fluorescence techniques are used to investigate the kinetics of expansion of the polymer coil. The system is suggested as a suitable model for the interaction of pyrene with biopolymers such as DNA. 13 figures, 1 table.
- Research Organization:
- Univ. of Notre Dame, IN
- OSTI ID:
- 7037192
- Journal Information:
- J. Polym. Sci.; (United States), Vol. 17
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
PYRENE
FLUORESCENCE SPECTROSCOPY
PHOTOIONIZATION
AQUEOUS SOLUTIONS
DNA
ELECTRON TRANSFER
EXCITED STATES
EXPERIMENTAL DATA
LASER RADIATION
MEDIUM TEMPERATURE
METHANOL
MICELLAR SYSTEMS
MONOCARBOXYLIC ACIDS
ORGANIC POLYMERS
PH VALUE
QUENCHING
SOLUBILITY
SURFACTANTS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
VISCOSITY
ALCOHOLS
AROMATICS
CARBOXYLIC ACIDS
CONDENSED AROMATICS
DATA
DISPERSIONS
ELECTROMAGNETIC RADIATION
EMISSION SPECTROSCOPY
ENERGY LEVELS
HYDROCARBONS
HYDROXY COMPOUNDS
INFORMATION
IONIZATION
MIXTURES
NUCLEIC ACIDS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
POLYMERS
RADIATIONS
SOLUTIONS
SPECTROSCOPY
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)
400500 - Photochemistry