The OPLS-all-atom forcefield was used for modeling the PE brushes and validated in prior studies for capturing the solvation properties and the responses of the brushes to counterions. The system was solvated with SPC/E water, and counterions were added to neutralize the chains. Also, an additional 64 Na + and Cl -ions were included, representing a 0.2 M NaCl solution. Ion interactions were modeled using Joung-Chetham parameters. The system was first energy-minimized and equilibrated under NPzT conditions (300 K, 1 atm) using a Nosé-Hoover thermostat and barostat, followed by further equilibration in the NVT ensemble. Long-range Coulomb interactions between the charged entities present in the system were computed using the PPPM (particle-particle particle-mesh) method with slab geometry adjustments. A time step of 2 fs was used to integrate the velocity field using the Velocity Verlet algorithm. For flow simulations, axial electric fields (E=0.1,0.5,1.0 V/nm) were considered. The effect of the electric field on different atoms was represented by ascribing forces to these atoms that are proportional to the charges of these atoms (similar to that considered in our previous studies considering EOS transport in brush-grafted nanochannels ). Also, to remove the dissipated heat, a thermostat was applied to water and ions in one-quarter of the channel. A Langevin thermostat was applied to the brushes to mimic the thermal wall control. The system was considered to reach a steady state when the velocity profiles and the average brush heights stabilized. Much more details of this MD simulation procedure for capturing the EOS transport in nanochannels grafted with the PMETAC brushes have been discussed in our previous paper. 59