Effect of the bridging conformation of polyelectrolytes on the static and dynamic behavior of macroions.

Abstract

A Brownian dynamics (BD) simulation is performed to investigate the effect of the bridging conformation of a polyelectrolyte (PE) with two charged heads (two-heads PE) on the radial distribution function (RDF) and diffusion behavior of macroions on the basis of the coarse grained model. For comparison, the system containing macroions and the PE with only one charged head (one-head PE) is also investigated. The simulation results indicate that, at low concentrations, the bridging effect of the two-heads PE chain leads to correlation of macroions. The reason is that at low concentration the gyration radius of the PE chain is less than the average distance between two macroions. When the two-heads PE chains are adsorbed on different macroions, the bridging effect of the PE chain dominates the RDF and diffusion behavior of the macroions. With the increase of the concentration of the system, when the gyration radius of the PE chain is greater than the average distance between two macroions, the bridging effect of the PE chain becomes trivial. By investigating the mechanism of the two-heads PE chain affecting the static and dynamic properties of the macroions, we can provide useful information for the synthesis of stabilizers and destabilizers of colloidal particles.