Helical wrapping of diblock copolymers on nanocylinder

The development of the helical structure of diblock copolymers in solutions or melts is a challenging task although helices can be readily formed in a confined environment such as nanopore. In this study, dissipative particle dynamic simulations are performed to explore helical supramolecular structures self-assembled from diblock copolymers induced by nanocylinder. At low polymer concentrations, helical ellipsoids are formed on the nanocylinder and they remain stable after the nanocylinder is removed. As the concentration increases, three types of cylindrical morphologies appear: single-single helix, double-double helix, or segmented structures. The influences of block lengths and block-nanocylinder interaction on suprastructures are shown in the morphological phase diagram. When the nanocylinder is bounded by two planes, a helical funnel can emerge. In the presence of a ring-like nanoparticle, a helical toroid can arise. Our simulation results provide a new strategy for the fabrication of various helical assemblies of diblock copolymers in solutions.