Molecular dynamics simulations of bottlebrush macromolecules in two dimensional polymeric melts under flow conditions

Abstract

Using molecular dynamics simulations and theoretical analysis we studied dynamics of a bottlebrush macromolecule in a matrix of linear chains under flow conditions. Our simulations showed that the velocity of a bottlebrush depends on the degree of polymerization of the brush backbone, degree of polymerization of the side chains and degree of polymerization of the linear chains. The velocity of a bottlebrush, first, decreases with increasing the bottlebrush degree of polymerization then it saturates. The location of the saturation regime was shown to be a universal function of the bottlebrush area. This behavior was explained by a combined effect of the hydrodynamic drag acting on a bottlebrush macromolecule from the matrix of faster moving linear chains and by the difference in the friction coefficients of a bottlebrush macromolecule and of linear chains with a substrate. A proposed theoretical model of bottlebrush dynamics under flow conditions is in a good agreement with simulation results.