FIG. 10.

Observations of dehydration-based selectivity in 2D membranes. (a) Membrane potential versus etch time (pore radius) showing weak selectivity in subnanoscale graphene pores (O’Hern et al., 2014), consistent with dehydration. (b) Schematic of permeation through GO layers in the experiments by Abraham et al. (2017). (c) Permeation rate, P, in units of P₀ = 1 mol h⁻¹m⁻², of water and ions for the variable interlayer separation in (b). For water, the permeation increases linearly with increasing interlayer spacing, whereas for ions it increases exponentially. (d) Permeation rate for K⁺ ions in (b) versus temperature showing Arrhenius behavior. All dashed connecting lines are guides to the eye only.