(166u) A Corona Phase Hamiltonian for Cylindrical Nanoparticle-Polymer Interactions

Nanoparticle surfaces, such as cylindrical nanowires and carbon nanotubes, are commonly decorated with adsorbed polymer corona phases to impart solution stabilization and to control molecular interactions. While the specific configuration of this corona phase is critical to interfacial interactions, the prediction of its most basic properties remains an unresolved problem in polymer physics. In this work, we construct the Hamiltonian describing the adsorption of an otherwise linear polymer to the surface of a cylindrical nanorod in the form of an integral equation summing up the energetic contributions corresponding to polymer bending, confinement, solvation and electrostatics. An approximate functional that allows for the solution of the minimum energy configuration in the strongly bound limit is shown to predict the pitch and surface area of observed helical corona phases in the literature from the surface binding energy and persistence length. This approximate functional also predicts and quantitatively describes recently observed ionic strength-mediated phase transitions of charged polymer corona at carbon nanotube surfaces. The Hamiltonian and approximate functional provide a theoretical link between polymer mechanical and chemical properties and the resulting adsorbed phase configuration, and therefore should find widespread utility in predicting corona phase structure around nanoparticles.