Facile Defect Engineering of Zeolitic Imidazolate Frameworks towards Enhanced C3H6/C3H8 Separation Performance. (26th August 2021)

• Record Type: Journal Article
• Authors: An, Heseong; Cho, Kie Yong; Lyu, Qiang; Chiou, Da‐Shiuan; Nam, Ki Jin; Kang, Dun‐Yen; Lin, Li‐Chiang; Lee, Jong Suk
• Is Part Of: Advanced functional materials. Volume 31:Number 47(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-08-26
• Subjects: amine modulator -- defect engineering -- mixed matrix membrane -- propylene/propane gas separation -- zeolitic imidazolate framework; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202105577
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Membrane‐based olefin/paraffin separations can be an attractive alternative to the current energy‐intensive cryogenic distillation for their high energy efficiency. This paper reports an amine modulator‐induced defect engineering of zeolitic imidazolate framework‐8 (AZIF8) nanoparticles (60 nm) for enhanced molecular sieving ability and good compatibility with various polymer matrices. It is revealed that an initial suppression of nuclei formation during synthesis enables amine modulators to deprotonate the neutral organic ligand as well as coordinate with Zn 2+ ions. The resulting AZIF8s exhibit more rigid characteristics compared to the conventional ZIF‐8 counterparts as demonstrated by its delayed gate opening pressure. Molecular dynamics simulations also suggest that AZIF8s exhibit a narrower pore size distribution with a smaller opening compared to the conventional ZIF‐8 analogues, which makes them more suitable for size‐discrimination between C3 H6 and C3 H8 . Furthermore, the coordination of alkyl amines into frameworks allows excellent compatibility with various commercial polymer matrices. The highly concentrated 6FDA‐DAM/AZIF8 (50/50 w/w) mixed matrix membrane (MMM) exhibits superior C3 H6 /C3 H8 separation performance (C3 H6 permeability of 79.38 Barrer and C3 H6 /C3 H8 selectivity of 39.8 at single gas condition) to most existing MMMs. The structural engineering proposed herein can be applied to other metal–organic frameworks for optimizing their performance in molecular separations. Abstract : This paper reports the molecular engineering of zeolitic imidazolate framework (ZIF) nanoparticles with enhanced molecular sieving ability for C3 H6 /C3 H8 separation and dispersibility via an alkyl amine‐induced defect engineering approach. The highly concentrated 6FDA‐DAM/defect‐engineered ZIF‐8 (50/50 w/w) mixed matrix membrane exhibits superior C3 H6 /C3 H8 separation performance to most existing reported analogues.