(470f) Self-Assembly of Diblock Copolymers In Nanopatterned Confinement: Insight from Dissipative Particle Dynamics Simulations

Lisal, M., Academy of Sciences of the Czech Republic
Brennan, J. K., U.S. Army Research Laboratory

In the bulk, diblock copolymers self-assemble into lamellar, cylindrical, gyroid and micellar nanostructures depending on the chemical incompatibility between the copolymer blocks and the ratio of the block lengths. However, in confinement interfacial interactions, symmetry breaking, structural frustration, confinement-induced entropy loss, and nanopatterned surfaces play a determining role which lead to nanostructures that differ from those found in the bulk. The intriguing prospects of diblock copolymer self-assembly in nanopatterned confinement from a technological viewpoint are the novel nanostructures that can be achieved and that furthermore may serve as templates for other nanostructures. In this study, the dissipative particle dynamics method is used to simulate the formation of nanostructures for symmetric and asymmetric diblock copolymers between nanopatterned planar surfaces. The nanopatterned surface is mimicked by a homogenous surface with alternating portions of the surface which interact differently with the diblock copolymers. The formation of the diblock-copolymer nanostructures between the planar surfaces is investigated and characterized by varying the separation width, the area and mutual location of the nanopatterns, and the strength of the interaction between the nanopattern and the diblock copolymers.