Polystyrene energy migration

CMS and Polystyrene Solutions in Cyclohexane. Both monomer and excimer fluorescences were observed in the pulse radiolysis of polystyrene solution in cyclohexane. The decay curves of monomer and excimer fluorescences at 287 and 360 nm are shown in Figures 7(a) and (b), respectively. Energy migration on the polymer chain has been discussed elsewhere (15). The dependences of the decay of monomer fluorescence and the rise of excimer fluorescence on the... 

One point which can be settled qualitatively, however, is whether singlet exciton migration does in fact occur in the aryl vinyl polymers. It will be shown that available evidence supports energy migration as an important feature of the photophysics of polystyrene (PS), poly(l-vinyl naphthalene) (P1VN), and poly(2-vinyl naphthalene) (P2VN), the homopolymers which are the subject of the majority of the review. 

Evidence for Energy Migration in Poiy(2-vinylnaphthalene) and Polystyrene... 

Excimer formation and energy migration and its relationship toward an understanding of molecular mobility in polymers remains to be the nost prolific area of study in luminescence analysis. Measurements on excimer fluorescence from copolymers of polystyrene with various acrylates has shown that excimer formation is directly related to the... 

The photophysical behavior of poly(vinyl aromatics) has stimulated much interest from both practical and theoretical points of view. The proposal that such molecules exhibit electronic energy migration, e.e.m., resulted in, among other things, development of the concept of synthetic antennae macromolecules (1 ). The object of this paper is to introduce a note of caution to interpretation of observed photophysical phenomena. The bulk of the discussion is concerned with polystyrene, although the behaviour of poly(vinyl naphthalene) will also be considered. 

In co-polymers, heterogeneity of environment of a chromophore by virtue of composition becomes of overriding concern. In our earlier work on co-polymers of vinyl naphthalene (4-10) and polystyrene (11-13), the models adopted to explain results deliberately emphasised heterogeneity at the expense of, say, energy migration. 

Excimer formation has been studied in polystyrene and poly(a-alkylstyrenes)189 (PS), poly(vinylcarbazole),139>140 poly-(2-vinylnaphthalene), and poly-(4-vinyl-biphenyl).141 For polystyrene films, David et a/.189 showed that the fluorescence yield increased with increasing crystallinity, at both ambient temperature and 77 K. The contribution of excimer fluorescence yield increased in the sequence atactic (0.7) < atactic oriented (0.60) < isotactic amorphous (0.28) < isotactic crystallized (0.01), with normal yields relative to excimer given in parentheses. Similar results were obtained for poly(vinylcarbazole), PVCZ, although the contribution of excimer fluorescence at 77 was independent of crystallinity. The results can be interpreted in terms of electronic energy migration to low-energy defect sites from which excimer emission can occur. In PVCZ copolymers with fumaronitrile (10), diethyl fumarate (11), and diethyl maleate (12) (Scheme 6),... 

In contrast, when 1% poly( 1-vinylnaphthalene) is blended with 99% polystyrene, the result is mainly polystyrene phosphorescence. These results lend themselves to the conclusion that energy migration must occur intramolecularly via the mani-... 

Gelles R, Frank CW (1982) Energy migration in the aromatic vinyl-polymers. 2. Miscible blends of polystyrene with polyvinyl methyl-ether). Macromolecules 15(3) 741-747. doi 10. 1021/ma00231a012... 

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