Molecular Simulation of Conformational and Structural Properties of Random Copolymer Nanoparticles

Abstract

Random copolymer nanoparticles are studied by Monte Carlo simulation of coarse-grained models on the second nearest neighbor diamond (2nnd) lattice. Molecular and surface properties of free-standing nanoparticle are characterized as a function of co-monomer fraction. "Polyethylene-like copolymer" chains are treated by the Rotational Isomeric State (RIS) model of polyethylene (PE). To mimic the characteristics of copolymer chain, non-bonded interactions with stronger attraction of comonomer units are described by different Lennard-Jones (LJ) potential parameters. For higher co-monomer fraction, the bulk densities of nanoparticles are increased and the interfacial profile is sharper. Molecular dimension and shape are changed as a function of co-monomer composition and mostly in the region close to the surface.