Order and Phase Behavior of a Cylinder Forming Diblock Copolymers and Nano-Particles Mixture in Confinement: A Molecular Dynamics Study

We study a coarse grained model of cylinder forming diblock copolymers and nano-particles (NPs) mixture confined between Lennard-Jones hard walls. Two models for non-selective interactions between monomers and NPs are applied. In the case of purely repulsive interactions between NPs and monomers (athermal case) strong segregation of NPs at the film surfaces and the formation of droplets of particles inside the copolymer film can be observed. For weakly attractive interactions between NPs and monomers (thermal case) formation of droplets of particles disappears and segregation on the film surfaces depend on temperature. The uptake of NPs by the copolymer film in the thermal case displays a non-monotonic dependence on temperature which can be qualitatively explained by a mean-field model. In both cases of nonselective interactions NPs are preferentially localized at the interface between the microphase domains.