Fabrication of a sandwiched silicalite-1 membrane in a 2D confined space for enhanced alcohol/water separation

Abstract

A dense zeolite layer with a thickness of approximately 500 nm was demonstrated by a confined-space strategy in a sandwiched mode of (SiO2)/(silicalite-1)/(SiO2). The gel-free secondary growth methodology bypasses the...

Pervaporation Zeolite-Based Composite Membranes for Solvent Separations

“…A current breakthrough in tailoring new concepts of zeolite-based membranes is that reported by Prof. Tsapatsis [ 59 ]. In this work, they designed a sandwiched (SiO 2 )/(silicalite-1)/(SiO 2 ) in a 2D confined space, as illustrated in Figure 4 .…”

“…Such yield is attractive for these applications, since hydrophobic membranes do not generally offer high fluxes. The authors stated that the unprecedented separation performance can be associated with several factors, such as the confined geometry improving intergrowth, by-skipping the calcination stage in the synthesis, diminishing defects, and the usage of a 2D material (such as graphene oxide) for the synthesis of silicalite-1 seeds fostering hydrophobicity in the final membrane [ 59 ]. To conclude, this novel membrane also stands out in the ability to operate over 14 days.…”

“… Graphical depiction of the sandwiched silicalite-1 membrane for the recovery of ethanol and n-butanol from water. Reproduced with permission from [ 59 ]; published by The Royal Society of Chemistry (RSC), 2020. …”

Functionalized MOF-Derived Nanoporous Carbon as Compatible Nanofiller to Fabricate Defect-Free PDMS-Based Mixed Matrix Pervaporation Membranes

“…Pervaporation (PV), as a promising membrane separation technology, has been successfully applied in recovering dilute biobutanol from fermentation broth due to the unique advantages of simple process, low energy consumption without secondary pollution, and restriction of vapor–liquid equilibrium. , To obtain an organophilic PV membrane for recovering butanol with a low concentration, polydimethylsiloxane (PDMS) is the currently used material because of its high hydrophobicity, excellent chemical stability, and good thermal properties. − However, the separation performance of the PDMS membrane is limited by the mutual restriction between permeability and selectivity, − restricting the further application of the PDMS membrane. Recently, doping hydrophobic nanoparticles such as metal organic frameworks (MOFs) into the PDMS matrix to prepare mixed matrix membranes (MMMs) turns out to be an effective way to break through the bottleneck. − MOFs, as a new type of crystalline material, are excellent fillers with high specific surface area and designable structure and pore size for preparing MMMs. − Although these membranes combine the advantages of PDMS and MOFs and improve the pervaporation performance to some extent, the acid byproducts in practical fermentation broth may destroy the structure of MOFs, , affecting the long-term stability and limiting the application of MOF-based MMMs in recovering butanol.…”

Contribution of Pore-Connectivity to Permeation Performance of Silicalite-1 Membrane; Part I, Pore Volume and Effective Pore Size

“…MFI-type zeolite membranes were studied previously for the separation of C 4 -C 8 hydrocarbons, such as butane isomers, hexane isomers and xylene isomers [4][5][6][7][8][9][10][11][12][13]. In addition, alcohol recovery from an aqueous solution was also carried out by using an MFI-type zeolite membrane [14,15]. Although some membranes have exhibited excellent separation performance, the flux is still too low to make them practical.…”