Self-assembly of ABC triblock copolymer into giant segmented wormlike micelles in dilute solution

We report the self-assembly of a linear ABC triblock copolymer into the previously unknown architecture of giant segmented wormlike micelles (SWMs). The lengths and diameters of these giant SWMs were as high as ca. 10 mu m and 500 nm, respectively. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) analysis revealed that the SWMs comprised sequences of repeated elemental parts, i.e., disks having a thickness of ca. 65 nm. A most interesting feature is that disks having different diameters became connected through threads to form various giant segmented wormlike micelles. A kinetic study indicated that the process of SWM formation occurred basically through three stages: (1) the ABC triblock copolymer self-assembled into small spheres of ca. 38 nm diameter; (2) these small spheres joined together to form intermediate shuttlelike structures; (3) the spheres within the shuttlelike structures rearranged and underwent further adjustment to form the final SWMs.