2D-dual-spacing channel membranes for highperformance organic solvent nanofiltration

by S. Wang, D. K. Mahalingam, B. Sutisna, S. P. Nunes
Year: 2019 ISSN: DOI: 10.1039/c8a10872b

Bibliography

2D-dual-spacing channel membranes for highperformance organic solvent nanofiltration

S. Wang, D. Mahalingam, B. Sutisna, S. P. Nunes

J. Mater. Chem. A, 7, 11673 (2019)

Abstract

Two-dimensional (2D) lamellar membranes are highly advantageous in molecular separations. However,

the permeance-rejection trade-off is always a major challenge, since the permeant transport mostly

occurs in single-spacing channels with undesired microenvironments. Inspired by the structure of

aquaporins, we design alternating dual-spacing channel graphene oxide (GO) membranes, with locally

tailored chemical microenvironments, that give high permeance, high rejection and high stability in

organic solvent nanofiltration. This unique structure is easily constructed by in situ intercalating and

cross-linking scattered sub-5 nm silica nanoparticles in the GO interlayers. The hydrophilic nanoparticles

locally widen the interlayer channels to enhance the solvent permeance. In the alternating nanoparticlefree

areas, the GO layers simultaneously bend and the p–p interactions retain the narrow and

hydrophobic channels, promoting high solute rejection. With a 10-fold increase in water permeance and

unaffected rejection, the dual-spacing channel membranes exhibit one of the best performances for

organic solvent nanofiltration. The methanol permeance reaches 290 L m2 h1 bar1, with more than

90% rejection of dyes larger than 1.5 nm. This new approach of designing hierarchical channels in 2D

materials can be used for a wide spectrum of applications.