Robust ionic liquid@MOF composite as a versatile superprotonic conductor.

A highly performing proton conducting composite was prepared through the impregnation of EMIMCl ionic liquid in the mesoporous MIL-101(Cr)-SO3H MOF. The resulting EMIMCl@MIL-101(Cr)-SO3H composite displays high thermal and chemical stability, alongside retention of a high amount of EMIMCl even at temperatures as high as 500 K, as well as under moisture conditions. Remarkably, this composite exhibits outstanding proton conductivity not only at the anhydrous state (σ473 K = 1.5 × 10-3 S cm-S) but also under humidity (σ(343 K/60%-80%RH) ≥ 0.10 S cm-1) conditions. This makes EMIMCl@MIL-101(Cr)-SO3H a unique candidate to act as a solid state proton conductor for PEMFC applications under versatile conditions.

MOFs industrialization: a complete assessment of production costs.

The potential of safe and low-cost batch production processes for Metal-Organic Frameworks (MOFs) at an industrial scale has been evaluated based on the prototypical MOF MIL-160(Al), a bio-derived material of high practical interest that can be made with a high space-time yield using green ambient pressure conditions. A simple method to calculate the production cost of this material has been determined based on a simulated process constructed with the data collected from laboratory pilot large-scale tests taking into account for the first time in MOF cost evaluation all the process parameters such as the scale, the cost of the raw materials, recirculation, and washing. The investment for a production plant established the ground for the estimation of the complete cost. The expected cost ranged from ca. 55 $ per kg at 100 tons per year down to 29.5 $ per kg for 1 kton per year production with longer term perspectives of reaching costs below 10 $ per kg once the bio-derived ligand is considered for the large-scale production of bioplastics.

Enzyme Encapsulation in Mesoporous Metal-Organic Frameworks for Selective Biodegradation of Harmful Dye Molecules.

Microperoxidase-8, a small, peroxidase-type enzyme was immobilized into nanoparticles of the mesoporous and ultra-stable metal-organic framework (MOF) MIL-101(Cr). The immobilized enzyme fully retained its catalytic activity and exhibited enhanced resistance to acidic conditions. The biocatalyst was reusable and showed a long-term stability. By exploiting the properties of the MOF's framework, we demonstrated, for the first time, that the MOF matrix could act in synergy with the enzyme (Microperoxidase-8) and enhance selectivity the oxidation reaction of dyes. The oxidation rate of the harmful negatively charged dye (methyl orange) was significantly increased after enzyme immobilization, probably as a result of the pre-concentration of the methyl orange reactant owing to a charge matching between this dye and the MOF.

Influence of Filler Pore Structure and Polymer on the Performance of MOF-Based Mixed-Matrix Membranes for CO2 Capture.

To gain insight into the influence of metal-organic framework (MOF) fillers and polymers on membrane performance, eight different composites were studied by combining four MOFs and two polymers. MOF materials (NH2 -MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, and two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were selected as matrices. The best-performing MOF-polymer composites were prepared by loading 25 wt % of MIL-96(Al) as filler, which improved the permeability and selectivity of 6FDA-DAM to 32 and 10 %, while for Pebax they were enhanced to 25 and 18 %, respectively. The observed differences in membrane performance in the separation of CO2 from N2 are explained on the basis of gas solubility, diffusivity properties, and compatibility between the filler and polymer phases.

Evaporation-Directed Crack-Patterning of Metal-Organic Framework Colloidal Films and Their Application as Photonic Sensors.

A straightforward crack-patterning method is reported allowing the direct formation of periodic cracks in metal-organic framework (MOF) nanoparticle films during dip-coating deposition. The crack propagation and periodicity can be easily tailored by controlling the evaporation front and the withdrawal speed. Several MOF-patterned films can be fabricated on large surfaces and on several substrates (flat, curved or flexible) including the inner surface of a tube, not achievable by other lithographic techniques. We demonstrate that the periodic cracked arrays diffract light and, due to the MOF sorption properties, photonic vapor sensors are fabricated. A new concept of "in-tube", MOF-based diffraction grating sensors is proposed with outstanding sensitivity that can be easily tuned "on-demand" as function of the desired detection range.