ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
A versatile double-beam polarization fluorimeter has been constructed for measuring the polarization of fluorescence from polymer solutions, melts, and glasses. Polarizations can be determined over a range of temperatures from -20 to +80°C in a controlled atmosphere with a precision of ±0.001 to ±0.005 for the studies reported herein. Data collected at different temperatures for 1.5 × 10-5M solutions of 9,10-diphenylanthracene (PA) in di-n-butyl phthalate (BP) fit a relation of the Perrin type, 1/P = (1/P0) + (ST/η1), where P is the polarization, T is the absolute temperature, and η1 is the solvent viscosity. The constants P0 and S were 0.400 ± 0.005 and (7.4 ± 0.3) × 10-3 P/°K, respectively. Polarizations were also determined at 25.0 ± 0.1°C for BP solutions containing 1.5 × 10-5M PA and polystyrenes at various weight fractions w2 and molecular weights M. Rotational friction coefficients ζr deduced from these data showed no dependence on M from 5.1 × 104 to 8.6 × 105 g/mole, and a gradual increase as w2 was varied from 0 to 0.1. It is concluded from these results that PA is an especially attractive emitter for rotational diffusion studies in nonaqueous systems, and that the abrupt changes in ζr with w2 and M observed for some other emitter-polymer systems and attributed to onset of coil overlap are not universal characteristics of such systems.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1972.180101114
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