Shape Control of Charge-patterned Nanocontainers

Stimuli-responsive control of the shape of nanoparticle (NP) containers enables their application as adaptive drug-delivery carriers. NP shape adaptation also provides dynamic building blocks in the design of reconfigurable, biomimetic materials. Molecular dynamics (MD) simulations are used to explore the role of surface charge patterning in controlling electrostatically-driven shape deformation of hollow, elastic NPs. Charge patterns investigated include those commonly synthesized in inverse patchy colloids: Janus particles with (N = 2) patches, striped charge patterns (N > 2), and polyhedral patterns. For Janus patterns, transitions to convex bowl, flattened hemisphere, and concave spinning-top-like conformations occur depending on the salt concentration screening the electrostatic drive to deform. As the number of stripes increases (N > 2), NPs with charged terminating ends adopt disc and rod conformations. However, (N > 2) striped particles with neutral terminating ends form concavities reminiscent of lock-and-key colloids. We also explore the shapes of polyhedrally-patterned nanocontainers and discuss the intersection between pattern-driven and buckling-driven shape control.