Self-Assembly of Charged Diblock Copolymers with Reduced Backbone Polarity

Charged block copolymers that can self-assemble into a host of nanostructures offer a great opportunity as next generation battery electrolytes with outstanding ionic conductivity and mechanical robustness. The impact of ions on the self assembly of charged block copolymers, however, remains to be fully understood. In this article, we report the phase behavior of charged-neutral block copolymers where a relatively nonpolar matrix was employed in the charged block to boost the strength of electrostatic interaction. The phase behavior was established using small-angle X-ray scattering (SAXS). We found that the overall shape of the phase boundary between ordered and disordered states is asymmetric, tilting toward the charged block-lean side of the phase portrait. However, the composition windows of the ordered phases, such as lamellae and hexagonally packed cylinders observed in this study, are comparable to those of neutral diblock copolymers and are not obviously affected by the incorporation of charges. The results obtained in this work provide insight into the impact of ions on the self-assembly of charged block copolymers as well as the design of nanostructured polymer electrolytes.

Automated summary

Charged block copolymers have potential as next generation battery electrolytes due to their ability to self-assemble into various nanostructures with high ionic conductivity and mechanical strength. This study investigates the impact of ions on the self-assembly of charged block copolymers by employing a nonpolar matrix to enhance electrostatic interactions. The phase behavior was analyzed using small-angle X-ray scattering (SAXS), revealing an asymmetric shape of the phase boundary and comparable composition windows of ordered phases to neutral diblock copolymers. These findings provide insight into the design of nanostructured polymer electrolytes and the influence of ions on charged block copolymer self-assembly.