SHEAR-INDUCED CRYSTALLIZATION AND MELTING OF A MICELLAR SOLUTION

Di-block copolymers of polystyrene-b-ethylene-co-propylene in the sele ctive solvent dodecane form highly monodisperse spherical micelles. At concentrations above about 3 wt % these form microdomains with crysta lline order, and the type of lattice appears to depend on the shear tr eatment of the sample. Formation of long range order is enabled by ver y low shear rates and gives rise in small angle neutron scattering exp eriments to a pattern of diffraction spots. The formation of the long range order and the melting at high shear rates has been followed in a sequence of SANS experiments carried out on samples contained in a Co uette cell.