Real-time, 2D Langevin dynamics of charged bead-spring polymers in aqueous salt solution, with screened Coulomb interactions. Three systems are shown: a single polyelectrolyte, a complex coacervate of oppositely charged chains, and a polyelectrolyte brush grafted to an electrode. Beads can be dragged with the cursor, and hovering shows the Debye length λD to scale. In each case, the solvent and small ions are implicit. All monomers have a degree of attraction to one another, which is reduced by the like-charges along the backbone. The Bjerrum length (strength of electrostatics) is taken to be 0.7 nm, corresponding to water at room temperature.
Monovalent salt. Blood is about 150 mM, seawater about 600 mM.
Share of monomers carrying a charge, spaced evenly along each chain.
Chains anchored along the electrode. Changing it restarts the brush.