Fluorescence probe and pulsed field gradient NMR study of aqueous solutions of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)block copolymer F88

摘要

In aqueous solutons of the triblock copolymer F88 micelle formation has been studied by means of dual fluorescence of the probe molecule 1,3-bis(1-pyrene)propane monitoring visosity changes in its microenvironment.Mobility chanes of the polymer molecules on micellization were followed by means of pulsed field gradient (PFG) NMR.These results compecules on micellization were followed by means of pulsed field radient (PFG)NMR.These results complement a recentdetailed study of cis-trans isomerization of azo dyes as "kinetic probes" for structure formation in aqueus solutions of F88.Differences of the critical micellization temperatures determined by various methods,and in H_2O and D_2O as solvents,are discussed.Our results reflect the particular large content of polye(ethylene oxide) in F88 (80%) compared to other triblock copolymers of this type.