An Unconventional Rapid Synthesis of High Performance Metal–Organic Framework Membranes

Abstract

Metal-organic frameworks (MOFs) are attractive for gas separation membrane applications due to their microporous channels with tunable pore shape, size, and functionality. Conventional MOF membrane fabrication techniques, namely in situ and secondary growth, pose challenges for their wider commercial applications. These challenges include reproducility, scalability, and high manufacturing cost. Recognizing that the coordination chemistry of MOFs is fundamentally different from the covalent chemistry of zeolites, we developed a radically different strategy for MOF membrane synthesis. Using this new technique, we were able to produce continuous well-intergrown membranes of prototypical MOFs, HKUST-1 and ZIF-8, in a relatively short period of time (tens of min). With a minimal consumption of precursors and a greatly simplified synthesis protocol, our new technique provides potential for a continuous, scalable, reproducible, and easily commercializable route for the rapid synthesis of MOF membranes. RTD-prepared MOF membranes show greatly improved gas separation performances as compared to those prepared by conventional solvothermal methods, indicating improved membrane microstructure.

Carbon dioxide measurements using long period grating optical fibre sensor coated with metal organic framework HKUST-1

“…The SEM images allow the assessment of the coverage of the glass-slide substrate and of the uniformity This finding supports the hypothesis that 10 min of immersion in ethanol plays a similar role for the HKUST-1 crystallization as the Phase 2, rapid thermal development, for the in-situ crystallization technique (47). Although individual crystals could not be detected, the deposited HKUST-1 film had a structure that was different compared to the precursors suggesting the sufficient growth of HKUST-1 crystals.…”

“…Rapid thermal deposition can significantly decrease the crystallization time due to the rapid solvent evaporation at elevated temperature, but still enables the synthesis of well inter-grown MOF film (47).…”

Zeolitic imidazolate framework membranes for gas separation: A review of synthesis methods and gas separation performance

“…Membrane technology is an attractive alternative for the 41 purification of both incondensable inorganic gases (i.e. H 2 , CO 2 , 42 N 2 , O 2 , SF 6 , Ar, and CO) and condensable organic gases (i.e.…”

“…[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41], titania [23,42], YSC [43], ZnO [44], and SiO 2 [45]. Titania is 173 a substrate that promotes heterogeneous nucleation; however, it is 174 too expensive and brittle [25].…”

“…The resulting tubular membranes exhibited the micro-334 structure, thickness, and gas separation performance that were 335 defect-free and highly reproducible [55]. In another work, the 336 simplicity of rapid thermal deposition (RTD) was harnessed in 337 order to prepare tubular membranes with desirable effects 338 [41]. The effectiveness and successful attempt in tubular mem-339 brane syntheses using contra-diffusion method [27], in situ 340 crystallization [29] and hydrothermal seeding method [37] also 341 worth mentioning.…”