Structure of nanorod assembly in the gyroid phase of diblock copolymer.

Diblock copolymers undergo microphase separation to form various microstructures, for example, lamellar, gyroid, cylindrical, cubic phases depending on composition and segregation strength (Flory–Huggins parameter χ). Thus, it can act as template to organize doped nanomaterials into different 3D self-assembled structures located within the block copolymer matrix. Gyroid phase is one of the microstructures formed by block copolymer. It has a curved interfacial surface providing confinements throughout the matrix and thus can regulate the shape and sizes of self-assembled nanorods doped in it. Mesoscale simulation of model systems has been performed to explore the structure and dynamics of self-assembly of bundles formed by nanorods of different flexibilities in the gyroid phase of diblock copolymer matrix. Bundles of different shapes and sizes have been found to be formed depending on the nanorod bending flexibility and copolymer–nanorod interactions. The shape anisotropy (κ(2)) and radius of gyration (R(g)(2)) of bundles situated at different interfacial confining locations of block copolymer matrices have been investigated as a function of nanorod flexibility and nanorod–diblock copolymer miscibility.