Surface Charge Doping for Ion-Pairing Criticality in Confined Electrolytes (opens in new tab)

Dielectric confinement strengthens Coulomb correlations in quasi-two-dimensional electrolytes and can promote Bjerrum pairing in charge-neutral slits. Here we use a generalized Debye-Huckel-Bjerrum theory to show that weak surface charge changes this picture by stoichiometrically doping the slit with mobile counterions. These counterions maintain a finite screening floor, decouple microscopic pairing from macroscopic ionicity, and shift associat...