Ultrathin metal-organic framework nanosheets as a gutter layer for flexible composite gas separation membranes

Min Liu, Ke Xie, Mitchell D. Nothling, Paul Andrew Gurr, Shereen Siew Ling Tan, Qiang Fu, Paul A. Webley, Greg G. Qiao

Research output: Contribution to journalArticleResearchpeer-review

35 Citations (Scopus)

Abstract

Ultrathin metal-organic framework (MOF) nanosheets show great potential in various separation applications. In this study, MOF nanosheets are incorporated as a gutter layer in high-performance, flexible thin-film composite membranes (TFCMs) for CO2 separation. Ultrathin MOF nanosheets (∼3-4 nm) were prepared via a surfactant-assisted method and subsequently coated onto a flexible porous support by vacuum filtration. This produced an ultrathin (∼25 nm), extremely flat MOF layer, which serves as a highly permeable gutter with reduced gas resistance when compared with conventional polydimethylsiloxane gutter layers. Subsequent spin-coating of the ultrathin MOF gutter layer with a polymeric selective layer (Polyactive) afforded a TFCM exhibiting the best CO2 separation performance yet reported for a flexible composite membrane (CO2 permeance of ∼2100 GPU with a CO2/N2 ideal selectivity of ∼30). Several unique MOF nanosheets were examined as gutter layers, each differing with regard to structure and thickness (∼10 and ∼80 nm), with results indicating that flexibility in the ultrathin MOF layer is critical for optimized membrane performance. The inclusion of ultrathin MOF nanosheets into next-generation TFCMs has the potential for major improvements in gas separation performance over current composite membrane designs.

Original languageEnglish
Pages (from-to)11591-11599
Number of pages9
JournalACS Nano
Volume12
Issue number11
DOIs
Publication statusPublished - 24 Oct 2018
Externally publishedYes

Keywords

  • CO capture
  • flexible composite membrane
  • gutter layer
  • metalâorganic framework
  • nanosheet

Cite this