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The effect of different deprotonators as well as washing steps and drying procedure on the synthesis of ZIF-8 from the mother liquor was investigated. The morphology, thermal stability, crystallinity, and surface area of the synthesized MOF were investigated. In addition, life-cycle assessment (LCA) or, in other words, eco-balance, was implemented as well. LCA compares the full range of environmental effects associated with the product by evaluating all inputs and outputs of material flows and predicting how such flow will affect the environment. ZIF-8 nanocrystals were synthesized from the recycled mother liquors using NaOH or NH 4 OH thus preserving the main characteristics of the ZIF-8 nanoparticles derived from the initial synthesis. The rest of the characterization methods confirmed the suitability of the synthesis methodology considering the phase purity of the obtained ZIF-8 and nanometer size particles. This procedure enabled us not only to obtain phase pure ZIF-8 but also to substantially decrease the amount of solvent used for washing making it a sustainable process., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

An innovative procedure for positioning a monolayer of hydrophilic metal organic framework (MOF) MIL-101(Cr) (MIL, Materials of Institute Lavoisier) nanoparticles (NPs) in thin-film nanocomposite (TFN) membranes has been implemented by transferring a Langmuir-Schaefer (LS) film of the MOF in between the polyamide thin layer at the top and the cross-linked asymmetric polyimide (P84) support at the bottom. The presence and layout of the LS-MIL-101(Cr) monolayer in the TFN membrane was confirmed by scanning transmission electron microscopy imaging with a high-angle annular dark-field detector images and X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy, and atomic force microscopy analyses. This methodology requires the smallest amount of MOF reported to date, 3.8 μg cm -2 , and promotes the formation of a defect-free ultrathin MOF film. Although conventional TFN membranes tend to show MOF agglomerates that could contribute to the formation of unselective defects, LS-TFN membranes, characterized by a homogeneous and continuous MOF coating, exhibit an optimal membrane performance, without a significant decrease in selectivity. Outstanding methanol permeances, one of the best results reported to date, of 10.1 ± 0.5 L m -2 h -1 bar -1 when filtering sunset yellow and of 9.5 ± 2.1 L m -2 h -1 bar -1 when filtering rose bengal have been achieved in LS-TFN membranes with a rejection higher than 90% in all cases. Methanol permeates through the polyamide and the LS-MIL-101(Cr) monolayer, greatly enhanced by the MOF pore system, in comparison to thin-film composite and conventional TFN membranes (7.5 ± 0.7 and 7.7 ± 1.1 L m -2 h -1 bar -1 when filtering sunset yellow), respectively, in which polyamide areas free of MOF NPs are present.

Segmented microfluidics was applied to the ultrafast crystallization of dicarboxylate based MIL-88B type metal-organic frameworks (MOFs; Fe-MIL-88B-NH2, Fe-MIL-88B, and Fe-MIL-88B-Br). Particular attention was paid to the influence of the temperature, residence time, and slug volume on the size and crystal size distribution of the MOFs. Average sizes in the 90-900 nm range with relatively narrow crystal size distributions were obtained with residence times as short as 20 s depending on the MOF type and synthesis conditions.