COLLECTIVE DYNAMICS OF TETHERED CHAINS - BREATHING MODES

Polystyrene(PS)-polyisoprene(PI) diblock copolymers dissolved in n-dec ane aggregate into spherical micelles with a PS core and a corona of t ethered PI chains. The PI corona may be considered as a brush on the s urface of a sphere or as the outer part of a many-armed polymer star. The thermal density fluctuations of the PI corona have been observed b y neutron spin-echo spectroscopy. The peculiar multi-decay time relaxa tion behavior can be described remarkably well by a model based on an idea of de Gennes for treating the corona as a semidilute polymer solu tion with varying concentration profile.