REMOVED: Multicomponent Gas and Vapour Sorption in High Free Volume Polymers

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Fabrication of ultrathin films containing the metal organic framework Fe-MIL-88B-NH2 by the Langmuir-Blodgett technique

In this work, the fabrication of ultrathin films containing the metal organic framework (MOF) Fe-MIL- 88B-NH2 by the Langmuir–Blodgett (LB) technique has been explored. MOF crystals of two different sizes (1.5 ± 0.3 and 0.07 ± 0.01 µm) have been synthesized and assembled at the air–liquid interface by the LB method. The effect of the subphase pH and particle size on the film formation process has been studied. Moreover, for the first time, mixed MOF+polymer (the commercial soluble polyimide Matrimid®) LB films containing different MOF loadings have been fabricated. These experiments show that it is possible to obtain ultrathin MOF + polymer films with a controlled MOF density. Furthermore, MOF particles are homogeneously distributed in the polymer matrix, even with very large amounts of MOF (up to 95 wt%). LB films have been incorporated into materials of different nature, including glass and mica substrates and also polymeric membranes based on polysulfone Udel® and PIM-1 (polymer of intrinsic microporosity), and the modification of water contact angle after LB film deposition has been analyzed

High density heterogenisation of molecular electrocatalysts in a rigid intrinsically microporous polymer host

A water-insoluble Polymer with Intrinsic Microporosity (or PIM, here for the particular case of the Tröger Base system PIM-EA-TB, BET area ca. 103 m2 g−1) is demonstrated to act as a rigid host environment for highly water-insoluble molecular catalysts, here tetraphenylporphyrinato-iron (FeTPP), surrounded by aqueous solution-filled micropores. A PIM-EA-TB film containing catalyst is deposited onto the electrode and immersed for voltammetry (i) with 4-(3-phenyl-propyl)-pyridine to give an organogel, or (ii) bare directly into aqueous solution. The porous host allows processes to be optimised as a function of solution phase, composition, and catalyst loading. Effective electron transfer as well as effective electrocatalysis is reported for aqueous oxygen and peroxide reduction. Given the use of completely water-insoluble catalyst systems, the methodology offers potential for application with a wide range of hitherto unexplored molecular electrocatalysts and catalyst combinations in aqueous media. Keywords: Electrocatalysis, Ion transfer, Peroxide, Oxygen, Fuel cell, Sensin

Intrinsically porous polymer protects catalytic gold particles for enzymeless glucose oxidation

The enzymeless glucose oxidation process readily occurs on nano-gold electrocatalyst at pH 7, but it is highly susceptible to poisoning (competitive binding), for example from protein or chloride. Is it shown here that gold nanoparticle catalyst can be protected against poisoning by a polymer of intrinsic microporosity (PIM-EA-TB with BET surface area 1027 m2 g−1). This PIM material when protonated, achieves a triple catalyst protection effect by (i) size selective repulsion of larger protein molecules (albumins) and (ii) membrane ion selection effects, and (iii) membrane ion activity effects. PIM materials allow “environmental control” to be introduced in electrocatalytic processes

Hydrogen Separation at High Temperature with Dense and Asymmetric Membranes Based on PIM-EA(H2)-TB/PBI Blends

The preparation of dense and asymmetric flat membranes from the blending of polybenzimidazole (PBI) and (1.5-20 wt %) of a polymer of intrinsic microporosity (PIM-EA(H2)-TB) is reported. Thermal characterization validated the blend by revealing a single glass transition temperature, which suggests the absence of polymer phase segregation. In addition, the decomposition activation energy and d-spacing of the blends follow trends that correlate with the amount of PIM component. The membranes have been tested for the separation of H2/CO2 mixtures. The properties of the dense membranes, which also incorporate zeolitic imidazolate-8 (ZIF-8) nanoparticles, helped understanding of the behavior of the PIM/PBI blends by which phase inversion results in high separation performance asymmetric membranes. Asymmetric membranes show H2/CO2 selectivities of 23.8 (10/90 wt % PIM/PBI) and 19.4 (20/80 wt % PIM/PBI) together with respective H2 permeances of 57.9 and 83.5 GPU at 250 °C and 6 bar feed pressure. The gas separation performance of these asymmetric blends has been fitted to an empirical model, showing the influence of the amount of PIM and the feed pressure