ELASTIC-SCATTERING AND RELAXATION MODES OF CYCLIC DIBLOCK COPOLYMER CHAINS IN SOLUTION - ROUSE MODEL

In this work the static and dynamic scattering properties of (A-B), ri ng diblock copolymer chains in the semi-dilute solutions are discussed . The case of a symmetric diblock in a solvent satisfying the optical theta condition is considered in detail. The results show substantial differences with respect to linear diblock copolymers. This is mainly due to the effect of connectivity of the chain extremities A and B, le ading to different conformations for both types of diblock copolymer c hains. The additional entropic interaction in cyclic chains induces a decrease of the scattering intensity and a shift of the location of it s maximum to a higher q value. As for the dynamic (in the Rouse model) , the fact that the two extremities are connected speeds up the freque ncy of the interdiffusion mode and shift its minimum to higher q value .