Lubrication by Polyelectrolyte brush bilayers: A joint density functional theory, perturbation expansion theory and scaling theory study

By combining the density functional theory, the perturbation expansion theory and scaling theory, the problem of Polyelectrolyte brush bilayers under stationary shear motion is investigated. Based on precise analysis, this system composed of four scenarios, each of which, bears three different regimes. These different scenarios arise when we consider the system with and without the hydrodynamic interactions as well as the system with weak and strong electrostatic interactions. Additionally, each scenario is divided into three different regimes based on the strength of the shear rate. Each scenario includes low shear rate, high shear rate and very high shear rate regimes.