Journal of Polymer Science Part B: Polymer Physics, Vol.41, No.14, 1615-1626, 2003
Energy migration in poly(N-vinyl carbazole) and its copolymers with methyl methacrylate: Fluorescence polarization, quenching, and molecular dynamics
Fluorescence polarization and quenching measurements were used to examine intramolecular energy migration for poly(N-vinyl carbazole) and copolymers of N-vinyl carbazole with methyl. methacrylate. Quenching measurements of the carbazole fluorescence by CCl4 were performed in dilute solution in toluene, and fluorescence anisotropy, r, was measured for the chains dispersed in a solid matrix of poly(methyl methacrylate) (PMMA). The results suggested that the chains with a high carbazole content, that is, a high content of excimer trapping sites, do not show the highest values of the singlet energy-migration rate. Isotropies, r(-1), of the samples in vitrified PMMA corroborated such conclusions. Molecular dynamics simulations on isotactic and syndiotactic trichromophoric copolymer fragments were used to obtain parameters related to the energy-transfer process as a function of the methyl methacrylate content. The parameters from the simulations supported the interpretation of the experiments. (C) 2003 Wiley Periodicals, Inc.
Keywords:poly(N-vinyl carbazole);energy transfer;energy migration;quenching;fluorescence;molecular dynamics;copolymerization