Fouling-resistant reverse osmosis membranes grafted with 2-aminoethanethiol having a low interaction energy with charged foulants

Abstract

Many fouling-resistant materials have been grafted or coated on the RO membrane surface for fouling-resistance. However, these modified RO membranes still exhibit a fast flux drop towards small charged organic foulants. Herein, we creatively use the quantum chemistry method to screen the thiol group having a close to zero interaction energy with small charged organic foulants. Thus, we selected a small molecule of 2-aminoethanethiol (AET) having a fouling-resistant thiol group and a reactive amine group for RO membrane surface modification. The water permeance of the AET-grafted RO membrane increases from 2.6 ± 0.1 L m−2 h−1 bar−1 to 3.2 ± 0.05 L m−2 h−1 bar−1, 23% higher than that of the pristine membrane. Moreover, the AET-grafted RO membrane exhibits excellent fouling resistance against charged surfactants. Our study offers insights on the design of fouling-resistant molecules for antifouling surface modification of RO membranes towards small charged organic foulants.