|Title||VISCOSITY DEPENDENCE OF THE LOCAL SEGMENTAL DYNAMICS OF ANTHRACENE-LABELED POLYSTYRENE IN DILUTE-SOLUTION|
|Publication Type||Journal Article|
|Year of Publication||1991|
|Authors||Waldow, D. A., M. D. Ediger, Y. Yamaguchi, Y. Matsushita, and I. Noda|
|Type of Article||Article|
|Keywords||1,9-DIMETHYLANTHRACENE, CHAINS, FLUORESCENCE ANISOTROPY DECAY, MODELS, POLARIZATION, POLYISOPRENE, POLYMERS, ROTATION|
The local segmental dynamics of anthracene-labeled polystyrene in dilute solution have been studied by using time-correlated single-photon counting. Six solvents covering 2 decades in viscosity were utilized. Correlation times were extracted from the orientation autocorrelation functions and determined as a function of temperature in all solvents. Under good solvent conditions, the correlation time is proportional to eta-0.9 at constant temperature, in reasonable agreement with the eta-1.0 prediction to the Kramers' equation in the high-friction limit. Other aspects of the results are also reasonably consistent with the assumption that the solvent acts as a viscous continuum. As noted in previous investigations, somewhat slower dynamics are observed in THETA-solvents than in good solvents. The potential barrier height for local dynamics extracted from these measurements is 11 +/- 3 kJ/mol.