초록 |
Network morphologies of functional block copolymers have been receiving spotlight to improve the optical, mechanical and transport properties. Nevertheless, because of the narrow thermodynamic stability window of network morphologies in block copolymers, it has not been trivial to design targeted structures. Key is the control of packing frustration and various approaches such as increasing molecular weight distribution, blending homopolymers, and modifying junctions, have been attempted for this, yet the methodology has not been reliably credited. In this study, a simple but powerful end-group chemistry is proposed to stabilize network morphologies of block copolymers. A set of polystyrene-b-poly(ethylene oxide) block copolymers with different end-functional moieties and junction linkers were synthesized, revealing remarkably rich network morphologies of gyroid (Ia3d), orthorhombic network (Fddd), and double primitive cubic structure (Im3m) at nominally symmetric block compositions. |