  We investigate end-effects in the ion distribution around strongly charged,
flexible polyelectrolytes with a quenched charge distribution by molecular
dynamics simulations of dilute polyelectrolyte solutions. We take the
counterions explicitly into account and calculate the full Coulomb interaction
via an Ewald summation method. We find that the free counterions of the
solution are distributed in such a way that a fraction of the chain charges is
effectively neutralized. This in turn leads to an effective charge distribution
which is similar to those found for weakly charged titrating polyelectrolytes
that have an annealed charge distribution. The delicate interplay between the
electrostatic interactions, the chain conformation and the counterion
distribution is studied in detail as a function of different system parameters
such as the chain length Nm, the charge fraction f, the charged particle
density rho, the ionic strength and the solvent quality. Comparisons are made
with predictions from a scaling theory.
