Capillary Rise Infiltration of Copolymers into Confined Packings

Capillary rise infiltration (CaRI) is a method through which numerous polymer architectures, such as block or random copolymers, can be infiltrated into a highly confined random close-packed nanoparticle packing. In contrast to the capillary rise infiltration kinetics of homopolymers, the microphase separation of block copolymers becomes a factor. In addition, wetting behaviors, where one monomer type prefers the nanoparticle surface, will alter the infiltration kinetics of both block and random copolymers. Here we present a computational study using molecular dynamics simulations to investigate the impact of polymer-nanoparticle interactions and polymer architecture on capillary rise infiltration kinetics in dense nanoparticle packings. The mechanisms underlying the infiltration of different polymer architectures (block and random copolymers) are explored by analyzing both transient chain level behavior, such as fraction of chains adsorbed to the gold surface and chain Rg during infiltration, as well as changes in the larger phase separated structures of block copolymers. We compare our findings with experimental results from capillary rise infiltration of poly-2-vinylpyridine (P2VP) and polystyrene into silica nanoparticle packings.