Behavior of a Polyion at the Charged Wall of the Same Sign in Presence of Counterions and of a System of two Equal Uncharged Polymer chains. Study by Monte Carlo Method

Abstract

In this paper Monte Carlo simulations of two polymer systems are presented. The first system is a single polyion near the plane charged wall of the same sign with presence of counterions. The interest in studying this system is stimulated by experiments on binding of negatively charged DNA deposited on the negatively charged substrate. [1] The second system contains two non-charged polymer chains with attractive or repulsive intrachain interaction and attraction between chains in both cases. Treatment of this system is aimed at further simulation of a system of polyions as the next step. In both cases the continuous and discrete models of chains were considered and Monte Carlo simulation method within Wang-Landau algorithm was used. It allowed to obtain the energy-distribution functions that in its turn made it possible to calculate various thermal properties of the systems in a wide temperature range: thermodynamic quantities and structural characteristics (root mean-square radius of gyration, root mean-square distance between the centers of mass of two polymers).