SOLVENT EFFECT ON FLUORESCENCE LIFETIMES AT SWOLLEN GLASSY-RUBBER INTERPHASE DOMAINS IN BLENDLIKE PARTICLES


PEKCAN O.

JOURNAL OF APPLIED POLYMER SCIENCE, cilt.57, ss.25-36, 1995 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 57 Konu: 1
  • Basım Tarihi: 1995
  • Doi Numarası: 10.1002/app.1995.070570103
  • Dergi Adı: JOURNAL OF APPLIED POLYMER SCIENCE
  • Sayfa Sayıları: ss.25-36

Özet

Fluorescence of naphthalene (N) labeled to poly(methyl metracrylate) (PMMA) particles sterically stabilized by polyisobutylene (PIE) was studied by transient fluorescence method in iso-octane, hexadecane, and in powder form. When samples of dispersions are annealed above 60 degrees C, their room temperature lifetimes increase, and when powder samples are so annealed, lifetimes decrease. Self-quenching effects among N*/N pairs were eliminated to isolate unimolecular lifetimes. Low-frequency intramolecular vibrations are found responsible for the temperature dependence of nonradiative transition of excited N molecules. Corresponding activation energies are measured and found to be between 2300 and 1100 cal/mol. Solvent effects on these activation energies are discussed. (C) 1995 John Wiley and Sons, Inc.