CONFORMATIONAL PROPERTIES OF WEAKLY CHARGED POLYELECTROLYTES FROM MONTE-CARLO SIMULATIONS

We present results of off-lattice Monte Carlo simulations of weakly charged chains where the charged beads interact with a screened Coulomb potential of Debye-Huckel type. The behaviour of the mean square end-to-end distance and mean-square radius of gyration versus chain length is discussed for various solution conditions characterized by the parameter zeta = 2lambda(D)/b, with lambda(D) being the Debye screening length and b the contour distance between neighbouring charged beads. We also evaluate the probability-density distribution for the end-to-end distance R. From the angular correlation function [cos gamma(k)] we estimate the persistence length as well as the chain length dependence of [R2] and [R(G)2]. With increasing zeta it is found to come close to that which is directly obtained from [R2(N)] and [R(G)2(N)]. Furthermore, the nonexponential decay of correlations indicates our charged chains to be not wormlike.