SMALL-ANGLE NEUTRON-SCATTERING STUDY OF THE MICELLE STRUCTURE OF AMPHIPHILIC BLOCK-COPOLYMERS

Amphiphilic block copolymers of vinyl ether were prepared by living cationic polymerization. The partially deuterated copolymers for SANS experiments were specially synthesized by introducing deuterated phenyl units into the hydrophobic chain. SANS measurements were performed for aqueous solutions of these copolymers by changing the H2O/D2O ratios. The SANS profiles indicate that the micelles in the present system exhibit a core-shell structure and that the size and shape of micelles are largely dependent on the length of the hydrophobic chain. The micelle of the shorter hydrophobic chain was found to be nearly spherical, whereas the micelle of the longer hydrophobic chain was confirmed to have an ellipsoidal shape.