Fig. 4: Ion sieving performance and transmembrane behaviour according to MD simulations.
a, PWP, Na2SO4 rejection and NaCl rejection of PA–SNFC membranes. The salt concentration was 1 g l−1; the applied pressure was 4 bar; the effective membrane area was 7.07 cm2; and the temperature was 298 K. b, Performance comparison of mono-/bivalent anion selectivity and water permeance with those of commercial and state-of-the-art membranes. The details are presented in Supplementary Table 4. c, Permeance and rejection of Na2SO4, MgSO4, CaSO4, MgCl2, CaCl2 and NaCl by PA–SNFC with an SNFC dosage of 7.14 μg cm−2. Error bars in a and c represent the standard deviation (s.d., n = 3, n derived from different experimental units) and data are presented as mean values ± s.d. d, Snapshots of MD simulations of the low charge density membrane model and high charge density membrane model at the initial and final states: the left chamber contained SO42− and water, and the right chamber contained PA structures with different charge densities. e, Time dependence of the MSD curves of SO42− for the low ionization intensity model and high ionization intensity model. f, Coulomb repulsive forces between SO42− and carboxyl groups in the PA structure of the low ionization intensity model and high ionization intensity model.
