Many polyelectrolytes (PEs), i.e., charged polymers like DNA, can be approximated by rigid charged rods. In aqueous solutions, rodlike charged macromolecules are surrounded by their counterions and often also by excess salt. Salt is a common means to control the effective charge of the molecules and their electrophoretic mobility, as well as their interactions with each other. In this presentation, the results of coarse-grained molecular dynamics simulations for PE systems in implicit water model with explicit ions are discussed. Here, we have mapped the ion size [1], aspect ratio [2], valency [2, 3], and salt concentration [1, 3] dependence of the ion distributions and PE interactions as well as EM of a single rigid DNA-like PE at room temperature.


Moreover, the interaction of PEs in water solutions with solid substrates in the presence of salt ions is an interesting theoretical problem due to the complex interplay between electrostatic and steric interactions. One of the fundamental questions in PE adsorption is controlling PE adsorption and dense layer formation at the substrate. The relevant parameters include the surface charge of the substrate, its dielectric constant, PE line charge, salt concentration, and counterion valency in the solution. To this end, we consider electrolyte solutions with one and two like-charged PEs on electrostatically neutral polarizable substrates with varying dielectric constants [4]. By considering the relevant system parameters listed above, we show how the type, range, and strength of the PE-PE and PE-substrate interactions can be adjusted.


Click the link to join this webinar


https://www.skyroom.online/ch/schoolofnanoscience/weeklyseminars