Perm-selective ultrathin high flux microporous polyaryl nanofilm for molecular separation

Abstract

Summary: Polymeric membranes with high permeance and selectivity performances are anticipated approach for water treatment. Separation membranes with moderate molecular weight cut-offs (MW in between 400 and 700 g mol−1) are desirable to separate multivalent ions and small molecules from a water stream. This requires polymeric membranes with controlled pore, pore size distribution, surface charge, and thin active layer to maximize membrane performance. Here, a fabrication of the polyaryl nanofilm with thickness down to ∼15 nm synthesized using interfacial polymerization onto ultrafiltration supports is described. Electron microscopy analysis reveals the presence of crumpled surface morphology in polyaryl nanofilm. Polyaryl nanofilm shows high water permeance of ∼110 Lm−2h−1 bar−1. Polyaryl nanofilm presents molecular weight cut-off greater than ∼450 gmol−1 (molecular marker) with water permeance of ∼84 Lm−2h−1 bar−1. Multivalent salt (K3[Fe(CN)6]) has higher rejection (>95%) as compared to the monovalent (∼5%) and divalent salt (∼28%) with the water permeance of ∼81 Lm−2h−1 bar−1.

Keywords

• Chemical engineering
• Membranes
• Nanotechnology
• Separation science