Excimer formation has been investigated in polystyrene, poly(1‐vinylnaphthalene), poly(2‐vinylnaphthalene), and in copolymers of 1‐vinylnaphthalene with styrene and with methyl methacrylate Solid films as well as solutions were studied over the temperature range 77–298°K In the solid polymers, interchain excimer formation is superimposed on the intrachain interaction observed in dilute solutions; intrachain excimer formation is essentially unaffected by the solvent in fluid solutions Conformations that lead to excimer interaction in a solid solution are fixed by the temperature at which the solid is formed Activation energies for intramolecular excimer formation for these polymers are somewhat less than those for the corresponding two‐unit model compounds and much less than those for the single‐unit model compounds While excimer sites act as efficient singlet traps for intramolecularly migrating energy and act to decrease the triplet yield, they do not present a barrier to the transfer of energy to a

Photophysical Processes in Polymers. IV. Excimer Formation in Vinylaromatic Polymers and Copolymers

The photogeneration of reactive species (RS) from dissolved organic matter (DOM) exhibits a great impact on the attenuation of pollutants in natural waters. However, the effect of metal ions on the...

Mechanistic Insight into the Effect of Metal Ions on Photogeneration of Reactive Species from Dissolved Organic Matter

The objective of this review is to characterize the excimer formation and energy migration processes in aryl vinyl polymers sufficiently well that the excimer probe may be used quantitatively to study polymer structure One such area of application in which some measure of success has already been achieved is in the analysis of the thermodynamics of multicomponent systems and the kinetics of phase separation In the future, it is likely that the technique will also prove fruitful in the study of structural order in liquid crystalline polymers

Photophysics of excimer formation in aryl vinyl polymers

Time-resolved fluorescence techniques in polymer and biopolymer studies

Luminescent groups in very weakly degraded polystyrene

Luminescence quenching in polystyrene + 9,10-diphenylanthracene + quencher and polystyrene + quencher systems has been investigated. In the latter system, the residual styrene monomer is regarded as a fluorescent solute. Result show that solvent quenching observed under uv excitation is due mainly to the competition between dipole-dipole energy transfer from polystyrene to the fluor and that from polystyrene to the quencher, and that such a transfer occurs directly from an excited polystyrene segment before it forms an excimer with an unexcited segment. Solvent quenching under beta-ray excitation was generally greater than that under uv excitation. It is suggested that this phenomenon may result from the occurrence of energy transfer at higher excited state of polystyrene. Solute quenching in some series of polystyrene + 9,10-diphenylanthracene + quencher is not accounted for by usual mechanisms of quenching. Such quenching can be explained by assuming energy transfer from the singlet excited sta...

C. Klkuchi

Papers

Energy Transfer and Quenching in Plastic Scintillators