Computer simulation of the competitive adsorption between polymers and small displacer molecules

Abstract

Competitive adsorption from mixtures of 50-segment homopolymer chains and 2-segment displacer molecules is studied by Monte Carlo computer simulation on a three-dimensional tetrahedral lattice. Changes in the configurational structure of the adsorbed polymer molecules are expressed in terms of the proportions of segments in trains, loops and tails. Numerical results are obtained as a function of the displacer concentration, the displacer adsorption energy, and the strength of the polymer-displacer segment interaction energy. Comparison is made between an isolated adsorbed polymer and a dense polymer system. The calculations show that the displacer surface coverage is a parameter of crucial importance in determining the extent of polymer displacement.