Charge density coordination and dynamics in a rodlike polyelectrolyte

Abstract

We study static and dynamic correlation functions of segmental charge density fluctuation on a rodlike polymer in ionic solutions. The polymer is described by an effective Hamiltonian which incorporates the Coulomb interaction between fluctuating charges screened by ionic fluid environment. We analytically calculate the correlation functions and discuss how charge distribution and dynamics are affected by counterion valency and concentration in electrolyte. We find that the charge correlation exhibits an underdamped oscillation with a wavelength comparable to the counterion size and with the amplitude increasing with the counterion valency. The dynamic correlation of charge density is shown to decay with a characteristic time varying with the counterion valency and concentration. The multivalency gives rise to faster decay of the correlation than that given by one dimensional diffusion.