Dynamic fluorescence quenching precedent to thermally-induced phase separation of poly(ethoxyethyl vinyl ether) aqueous solution

We focused on the stage preceding the thermally-induced phase separation of aqueous solution of poly(ethoxyethyl vinyl ether) (PEVE). Previously, we o bserved an interesting dynamic quenching just below the phase separation te mperature. The dynamic fluorescence quenching disappeared by addition of a surfactant. In systems without the phase separation of both the hexane solu tion of PEVE and the PEVE bulk, the fluorescence lifetime decreased monoton ically with the increase of temperature. These results indicated that the m arked decrease is due to the dynamic quenching by the collision between the fluorescent probe and the PEVE segment induced by the thermal fluctuation precedent to the phase separation.