Polyzwitterionic Material Structure and Dielectric Properties

There is a growing need for flexible, high dielectric constant materials that move beyond current polar solvent swelling and nanofiller approaches to advance energy storage and actuator applications. Here, we synthesized a series of statistical copolymers consisting of poly(2-(dimethylamino)ethyl acrylate)-co-polybutyl acrylate (PDMAEA-co-PBA) that were then converted into polyzwitterions to explore the impact of zwitterions on material structure and dielectric properties. The DMAEA residues in each copolymer were quaternized using 1,4-butane sultone to yield polyzwitterions through post-polymerization modification. The functionalization of the copolymers with zwitterions increases the static dielectric constant of the materials (i.e., ~9.3 at 80 °C) compared to the unquaternized materials. The strong dipolar interactions between zwitterions lead to aggregation, which was confirmed by X-ray scattering. Although the zwitterions increased the dielectric constant of the materials, the zwitterion-rich aggregates are posited to restrict zwitterion mobility, precluding maximum material dielectric constant. The reported findings position polyzwitterions as promising next-generation dielectric materials, potentially broadening applications in flexible electronics and energy-efficient devices.