Fig. 3: Graded molecular separation using the same GO/PG membrane.
From: Smart and solvent-switchable graphene-based membrane for graded molecular sieving
a Scheme showing ternary molecular separation of three dyes (phenol, VB, and RR 195) using one single GO/PG membrane in a two-step nanofiltration process. In step 1, only the smallest phenol molecules can permeate the membrane. In step 2, VB can permeate through the membrane, leaving RR 195 in the retentate. Note: The P and RR refer to phenol and RR 195, respectively. b, c UV-visible absorption spectra of (b) the feed mixture containing three molecules in water and its permeate, (c) feed solution after water nanofiltration (in 90 vol% of methanol), its permeate and retentate after the second step nanofiltration. The photographs show the mixture feedstock, the permeate collected in the first and second steps, and the retentate collected in the second step.
