Highly stable MIL-101(Cr) doped water permeable thin film nanocomposite membranes for water treatment

Abstract

Highly stable water permeable thin film MIL-101(Cr) nanocomposite membranes for water treatment were created via in situ interfacial polymerization on a polyether sulfone support. Lab-made MIL-101(Cr) nanoparticles (∼200 nm) were used to introduce direct water channels to a dense polyamide layer, which increased water permeance. On changing the amount and the method of MIL-101(Cr) nanoparticle addition, the surface topography and internal structure of the membranes were changed, leading to different separating properties of the membranes. Measured at 10 bar with 2000 ppm Na₂SO₄ solution, nanosized MIL-101(Cr) increased water permeance to 3.91 L m⁻² h⁻¹ bar⁻¹ at 0.2 w/v%, 158% higher than undoped membranes; meanwhile, high Na₂SO₄ rejection was maintained. This study experimentally verified the potential use of MIL-101(Cr) in advanced thin film nanocomposite membranes, which can be used in diversified water purification fields, including desalination and the removal of organics.