▎ 摘　　要

Ion adsorption within nanopores is involved in numerousapplications.However, a comprehensive understanding of the fundamental relationshipbetween in-pore ion concentration and pore size, particularly in thesub-2 nm range, is scarce. This study investigates the ion-species-dependentconcentration in multilayered graphene membranes (MGMs) with tunablenanoslit sizes (0.5-1.6 nm) using nuclear magnetic resonanceand computational simulations. For Na+-based electrolytesin MGMs, the concentration of anions in graphene nanoslits increasesin correlation with their chaotropic properties. As the nanoslit sizedecreases, the concentration of chaotropic ion (BF4 (-)) increases, whereas the concentration of kosmotropicions (Cit(3-), PO4 (3-))and other ions (Ac-, F-) decreasesor changes slightly. Notably, anions remain more concentrated thancounter Na+ ions, leading to electroneutrality breakdownand unipolar anion packing in MGMs. A continuum modeling approach,integrating molecular dynamic simulation with the Poisson-Boltzmannmodel, elucidates these observations by considering water-mediatedion-graphene non-electrostatic interactions and charge screeningfrom graphene walls.