Hydrophilic Montmorillonite in Tailoring the Structure and Selectivity of Polyamide Membrane

2D nanomaterials have been extensively studied for their superiority in desalination applications. For instance, the incorporation of Graphene-Family nanomaterials has been reported to enhance membrane separation performance significantly, yet the other important low-cost 2D nanomaterial, montmorillonite (MMT), is less studied. For the first time, we systematically studied the formation and performance of polyamide membranes with the modification of exfoliated MMT. The exfoliated MMT has overcome the classical membrane permeability-selectivity trade-off attributed to its uniformity, excellent dispersion and compatibility with monomer m-phenylenediamine (MPD). The effects of MMT charges on the perm-selectivity of resultant TFN membranes were also studied symmetrically. MMT can tailor the surface morphology, roughness, hydrophilicity, and crosslink density of polyamide due to tunable charges and ionic strength. In addition, it was found that MMT exhibited a positive effect on the chlorine resistance of the membrane. Taken together, our work provides fundamental insights into the formation and transport mechanisms in thin-film nanocomposite (TFN) membranes.