Throughout the paper, we have highlighted how the interactions between the PMETAC brushes and the Cl -counterions as well as the extent of their individual interactions with water molecules determine the brush structure, counterion distribution, and the eventual EOS transport in presence of an applied electric field. It is therefore important to understand the changes in the PMETAC-Cl --ion interaction, water structure, water sharing by different groups, etc. as a function of the strength of the applied electric field. In section S9 in the SI, therefore, we have discussed these issues in detail.