Exploring Network Morphologies in Block Copolymers

The exploration of three-dimensional (3D) nanostructures in block copolymers involves the manipulation of compositional fluctuations at interfaces, induction of conformational asymmetry, and design of complex architectures. Despite the abundance of such nanostructures identified to date (e.g., triply periodic minimal surfaces and Frank–Kasper phases), the experimental demonstration of thermodynamically stable complex 3D network structures with high packing frustration remains limited. In this talk, I would like to show the critical role of molecular interactions at polymer chain ends in stabilizing network morphologies and propose the use of end-group chemistry as a versatile approach to achieve thermodynamically stable network structures with high packing frustration in simple linear diblock copolymers. This strategy allows precise control over physical properties, nanoscale self-assembly, and interfacial functionality, all without altering the polymer backbone. I advocate revising conventional block copolymer phase diagrams to consider end–end interactions and end-group arrangements. In instances where end-functionalized block copolymers exhibit strong end–end interactions, a broader phase window is occupied by network structures such as gyroid, diamond, and primitive phases, instead of lamellar structures. This highlights the transformative potential of end-group chemistry in designing functional nanomaterials for emerging applications.