Response of Tb(III) and Eu(III) centered luminescence on phase transitions in aqueous solutions of triblock copolymers

The work introduces the temperature induced quenching of Tb(III) and Eu(III) centered luminescence sensitized by ligands 2,2′:6′,2″-terpyridine and difloxacin in aqueous solutions of triblock copolymers, namely (PEO)13(PPO)30(PEO)13 (L64), (PPO)14(PEO)24(PPO)14 (17R4) and (PPO)8(PEO)22(PPO)8 (10R5). The results reveal the temperature induced shifting of the complex formation equilibriums in solutions of the triblock copolymers as the reason of the quenching of Eu(III) and Tb(III) centered luminescence. The correlation between the temperature induced quenching and the aggregation behavior of the triblock copolymers is revealed. Both the nature of the ligand and the architecture of the triblock copolymer affect the Tb(III) and Eu(III) centered luminescence response to the temperature induced phase transitions.