Open-Pore Two-Dimensional MFI Zeolite Nanosheets for the Fabrication of Hydrocarbon-Isomer-Selective Membranes on Porous Polymer Supports...

摘要

Suspensions of two-dimensional zeolite nanosheets are known to function as effective building blocks for the design and fabrication of membranes and catalysts. Multilamellar (ML) Mordenite Framework Inverted (MFI) zeolites (or ML-MFI) have been synthesized using organic structure directing agents (OSDA) which, depending on the choice of agents, can result in the formation of lamellar assemblies. In addition, ML-MFI can be exfoliated to obtain single-layer 2D zeolite MFI nanosheets. Unlike other 2D materials, for which exfoliation can be achieved by various solution-based methods, exfoliation of ML-MFI have only been reported by polymer-melt-blending techniques. The MFI nanosheets obtained in this manner are hydrophobic and can be dispersed in non-polar solvents but not in water-a significant limitation since dispersion in water can enable layer-by-layer deposition for nanocomposite and thin-film fabrication. Moreover, the exfoliated nanosheets contain the OSDA in their micropores, preventing their use as molecular sieves.