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

Amphiphilic block copolymers of vinyl ether were prepared by living ca tionic polymerization. The partially deuterated copolymers for SANS ex periments 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 ex hibit a core-shell structure and that the size and shape of micelles a re largely dependent on the length of the hydrophobic chain. The micel le of the shorter hydrophobic chain was found to be nearly spherical, whereas the micelle of the longer hydrophobic chain was confirmed to h ave an ellipsoidal shape.