Theory and Simulation of Polymer Brushes - Interaction and Structure

Addition of polymer-grafted nanoparticles (NPs) to a polymer melt can result in hybrid materials with improved properties. Understanding of the structure and the interactions of polymer-grafted NPs in a melt is essential to improve their practical applicability. In this study, we focus on the fundamental aspects of the interactions and structure of polymer brushes in either a poor solvent (i.e., incorporating compressibility effects in the brush) or in a (compressible) polymer-matrix. First, we study two planar brushes in a poor solvent and then in a matrix-polymer melt by using theory and simulations. We study the dependence of monomer density distribution, brush height, and the interaction force between two brushes as a function of graft density and polymer chain length. Then we discuss the generalization of our results to a spherical geometry of relevance to the practically important testbed of polymer grafted nanoparticles.