Persistence length of weakly charged polyelectrolytes with variable intrinsic stiffness

We present simulations of a basic model of weakly charged polyelectrolyte chains of variable intrinsic stiffness within the Debye-Hückel approximation. Starting from the sublinear dependence of the electrostatic persistence length L e on the screening parameter for flexible chains, the corresponding effective exponent y ( L e ∼ κ − y ) crosses over to values up to 2 when the intrinsic persistence length L 0 exceeds the electrostatic one L e . L P shows a pronounced minimum with increasing intrinsic stiffness due to the occurrence of two relevant length scales which influence each other. This makes the concept of a unique persistence length for these systems questionable.