Energy transfer in polymers—IV. Singlet and triplet energy transfer in polymethylvinylketone films

The efficiency of transfer from the triplet of polymethylvinylketone (PMVK) to naphthalene has been measured at 77°K. The critical distance of transfer according to Hirayama is 11 · 3 Å. This is the usual value of R_o for exchange interaction without migration. Singlet energy transfer from the polymer to benzophenone occurs when donor and acceptor are very close together, at room temperature. In the system PMVK-anthracene, the emission spectrum shows that microcrystals of the additive are formed in the polymer even at low concentration.