Self-Assembly of End-functionalized Amphiphilic Block Copolymers

End-functionalization of block copolymers have emerged as a powerful strategy for regulating self-assembled nanostructures by controlling molecular interactions at polymer termini under confined geometries. Incorporating selective ion-dipole electrostatic interactions at polymer chain ends has provided an effective platform for designing complex network nanostructures by alleviating packing frustration. However, the role of dielectric constant of polymer chains bearing end-functional groups on the strength and organization of terminal interactions remains largely unexplored. Here, we investigate the phase behavior of amphiphilic diblock copolymers in which ionic moieties are selectively introduced at either the hydrophobic or hydrophilic block termini. This enables elucidation of how end-group aggregation and/or Coulombic interactions at polymer termini govern chain stretching and alleviate packing frustration. Furthermore, the morphologies of these end-functionalized block copolymers were investigated in the presence of added metal salts. Upon increasing salt concentration, the salts preferentially localized at the end-groups of low-dielectric hydrophobic polymers, while in hydrophilic polymers, the salts diffused throughout the block, diminishing the directionality of terminal interactions. This led to distinct self-assembled morphologies and the resulting structure-ion transport properties of the block copolymer electrolytes were systematically examined.