Macromolecules 1993,26, 7189-7194
7189
Formation of Micelles of Diblock and Triblock Copolymers in a Selective Solvent D. Izzot and C. M. Marques*** Institut Charles Sadron, 6 rue Boussingault, 67083 Strasbourg Cedex, France, and Instituto de mica da Universidade de Stio Paulo, Caixa Postal 20 516, 01498 S l o Paulo, Brazil Received May 6, 1993; Revised Manuscript Received September 24, 199P
ABSTRACT We study theoretically the formation of dilute phases of spherical (micelles), cylindrical
(vermicelles), and planar (lamellae) aggregates of copolymer chains in a selective solvent. In the case of diblock copolymer chains, micelles are formed for all values of the block asymmetryin the regime where dilute phaaes are predicted to occur (NA NB'"''), where the diblock copolymers have a collapsed block much larger than the swollen block, the lamellar dense phase always has a chemical potential lower than the two other phases (eqs 111.6, 111.12, and 111.16). In the intermediate regime (Ng15/11
