Shapes of Deformable Charge-patterned Nanoparticles

Deformable nanoparticles have received attention as candidates for designing stimuli-responsive nanocontainers for therapeutic applications. These systems are also investigated as dynamic building blocks for designing reconfigurable materials. Using molecular dynamics based simulated annealing, we investigate the shape of deformable nanoparticles for a variety of surface charge patterns including octahedral charged patches, single-charged spherical caps, and oppositely-charged spherical caps. Our simulations reveal that deformable nanoparticles of diameters within 20 - 100 nm adapt their shape differently in response to changes in pattern types and salt concentration over 0.01 - 10 mM. Shape transitions to faceted and rounded octahedra, spherocylinders, squared and rounded disks, capsules, variously-deformed bowls, and prolate spheroids are observed. Effects of counterion condensation on the stability of shape deformations are discussed. The observed shape transitions, controlled by pattern type and screening length, can change the directional specificity of interactions between nanoparticles, which may in turn hinder or promote reconfiguration in assembled materials.