Abstract
A well organized, three dimensionally packed nanohelical phase microstructure has been obtained by the self-assembly of chiral block copolymers, polystyrene-b-poly(L-lactide) (PS-PLLA) with PS-rich fractions, which have been transformed into cylinders by crystallization and shear. PS-PLLA diblock copolymers have been prepared by a double-headed polymerization sequence and finally quenched to room temperature for transmission electron microscopy (TEM) and X-ray scattering experiments. The observed core-shell cylinder microstructure arises from the chirality-driven twisting and bending of the bilayered microstructure through the scrolling of the helical microdomains. It demonstrates a potential route for generating a unique phase with helical sense from achiral components by using the chiral effect for microphase separation. The self-assembly of the degradable PS-PLLA diblock copolymers provides an easy and convenient way for preparing tubular nanostructures.