Hostname: page-component-848d4c4894-cjp7w Total loading time: 0 Render date: 2024-07-05T00:05:22.446Z Has data issue: false hasContentIssue false
  • English
  • Français

Excimer and Exciton Fusion of Blends and Molecularly Doped Polymers--A New Morphological Tool.

Published online by Cambridge University Press:  21 February 2011

Zhong-You Shi ,
Ching-Shan Li  and
Raoul Kopelman
Zhong-You Shi
Affiliation:
Department of Chemistry, The University of Michigan, Ann Arbor, MI 48109-1055
Ching-Shan Li
Affiliation:
Department of Chemistry, The University of Michigan, Ann Arbor, MI 48109-1055
Raoul Kopelman
Affiliation:
Department of Chemistry, The University of Michigan, Ann Arbor, MI 48109-1055
Get access

Abstract

Exciton-exciton and exciton-excimer triplet fusion kinetics is monitored in medium molecular weight P1VN/PMMA solvent cast films with concentrations from 0.005 to 100% (weight), at temperatures of 77 to 300 K, via time resolved fluorescence and phosphorescence (10 ns to 10 sec). The heterogeneity exponent (h) is 0.5 for isolated P1VN chains, zero (classical) for pure P1VN and “fractal-like” throughout certain concentration regimes. However, h is not monotonic with blend concentration but rather oscillates between zero and 0.5. Correlation is made with morphology changes (phase separation, filamentation). As expected, the triplet exciton kinetics is dominated by short-range hops (about 5 A) and thus monitors the primary topology of the chains. At concentrations below 0.01%, the excitons are constrained to a truly one-dimensional topology. At higher concentrations there is a fractal-like topology. Similar studies were conducted on naphthalene-doped PMMA (1-20% weight). The lower concentration samples are neither segregated nor random solution phases.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 171: Symposium O – Polymer Based Molecular Composites , 1989 , 245
Copyright
Copyright © Materials Research Society 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Thomas, E. L., Anderson, D. M., Henkee, C. S. and Hoffman, D., Nature 334 (6184), 598 (1988).Google Scholar
2. Gruner, S. M., et al., Biochemistry 27 (8), 2853 (1988).Google Scholar
3. Alward, D. B., Kinning, D. J., Thomas, E. L. and Fetters, L. J., Macromolecules 19 (1), 215 (1986); E. L. Thomas, D. B. Alward, D. J. Kinning, D. C. Martin, D. L. Handlin and L. J. Fetters, ibid., 19 (8), 2197 (1986); H. Hasegawa, H. Tanaka, K. Yamasaki and T. Hashimoto, ibid., 20 (7), 1651 (1987).Google Scholar
4. Kinning, D. J., Thomas, E. L. and Fetters, L. J., J. Chem. Phys. 90 (10), 5806 (1989).Google Scholar
5. Anderson, D. M. and Thomas, E. L., Macromolecules 21 (11), 3230 (1988).Google Scholar
6. Gobran, D. A., PhD thesis, University of Massachusetts, forthcoming.Google Scholar
7. Leibler, L., Orland, H. and Wheeler, J. C., J. Chem. Phys. 79 (7), 3550 (1983).Google Scholar
8. Kinning, D. J., Winey, K. I. and Thomas, E. L., Macromolecules 21 (12), 3502 (1988).Google Scholar
9. Wang, Z.-G. and Safran, S. A., Physique, J. de, in press; Europhys. Lett., in press.Google Scholar