Abstract
The ubiquity of polymers interacting with solid surfaces in nature makes the phenomenon of great importance in many fields. In this thesis, the behaviors of a single charged linear polyelectrolyte chain in solution at room temperature that is adsorbed on a charged surface have been investigated with molecular dynamic simulations. We investigated how the chain conformation is affected by the surface charge density. At low surface charge density, the chain conformation is not altered. As the surface charge density increases, the structure of polyelectrolyte becomes swollen which can be attributed to the decrease of counterion condensation and the effect of polyelectrolyte gets in touch with a charged surface. Once the surface charge density exceeds a critical value, anions that are dissolved from a charged surface begin to influence the adsorbed polyelectrolyte chain. And this will induce a compact structure of the chain. We also studied the dynamic properties of the adsorbed chain. At low surface charge density, the results of diffusion coefficient show that the chain follows the description of Rouse dynamics in bulk solution. However, when the surface charge density is high enough, the strong wall-polymer interaction will increase the friction. So the diffusion coefficient will decrease as the surface charge density increases. Those results can help us to understand the behaviors of a linear polyelectrolyte chain adsorbed on a charged surface.