The initial configurations are prepared by randomly distributing polymers, ions, and water molecules within an 8×8×8 nm 3 cubic simulation box using Packmol ; see Fig. . The DCPAM chains are modeled using the OPLS-AA force field , while water molecules are represented by the TIP3P model . All bonds in water molecules and DCPAMs are constrained using the SETTLE and LINCS algorithms, respectively. The interaction parameters for the Na + and Cl -ions are adopted from Refs. 83 and 84. The parameter for the NO - 3 ion is taken from Ref. . Periodic boundary conditions are applied in all three directions. A cutoff radius of 1 nm is applied for van der Waals (vdW) interactions. Long-range electrostatic interactions are treated using the Particle Mesh Ewald method with a real-space cutoff of 1 nm. The simulations are performed with a time step of 2 fs.