| Popis: |
Diblock polystyrene- block -poly(hydrogenated isoprene) was fluorescence labelled by random covalent attachment of anthracene at the polystyrene block (the average number of anthracenes per copolymer chain was 0.88). Micellization of the labelled copolymer was studied in a broad composition range of the solvent mixture 1,4- dioxane heptane . Micelles with polystyrene cores are formed in heptane-rich solvents (0–30 vol% 1,4-dioxane). In mixtures with 30–50 vol% 1,4-dioxane, the sample dissolves molecularly in the form of individual copolymer coils and in dioxane-rich solvents (more than 50 vol% 1,4-dioxane), micelles with polystyrene shells are formed. Micellar solutions were characterized by static and quasielastic light scattering and by sedimentation velocity measurements. The mobility of pendant fluorophores and polymer segments in micellar cores and shells in selective solvents and in individual copolymer coils in good solvents was studied by time-resolved fluorescence-anisotropy measurements. |
