68 research outputs found

    Metal-organic framework-activated carbon composite materials for the removal of ammonia from contaminated airstreams

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    L.N.M and R.E.M wish to acknowledge the financial support from the EPSRC industrial CASE award (grant EP/N50936X/1). A.T and G.B would like to thank the financial support from the Fondo per il finanziamento delle attività base di ricerca (grant PJ-RIC-FFABR_2017).Metal-organic frameworks (MOFs) are a class of porous materials that show promise in the removal of Toxic Industrial Chemicals (TICs) from contaminated airstreams, though their development for this application has so far been hindered by issues of water stability and the wide availability and low cost of traditionally used activated carbons. Here a series of three MOF-activated carbon composite materials with different MOF to carbon ratios are prepared by growing STAM-17-OEt crystals inside the commercially available BPL activated carbon. The composite materials display excellent water stability and increased uptake of ammonia gas when compared to unimpregnated carbon. Such properties make these composites very promising in the fields of air purification and personal protective equipment.PostprintPeer reviewe

    Structure effects induced by high mechanical compaction of STAM-17-OEt MOF powders

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    Financial support by PJ-RIC-FFABR_2017 and the EPSRC grant EPSRC industrial CASE award (grant EP/N50936X/1) are acknowledged. The research programme Nanoporous materials (P1-0021) financially supported by Slovenian Research Agency (ARRS) is acknowledged as well.Metal-organic frameworks (MOFs) are promising materials for many potential applications, spacing from gas storage to catalysis. However, the powder form of which they are generally made is not suitable, mainly because of the low packing density. Powder compaction is therefore necessary, but also challenging because of their typical mechanical fragility. Indeed, generally, they undergo irreversibly damages upon densification processes, for example partially or totally loosing microporosity and catalytic activity. In this work, we deeply study the compaction effects on the flexible Cu(II)-based MOF STAM-17-OEt  (Cu(C10O5H8)1.6 H2O), whose chemical composition is close to that of HKUST-1, obtaining that it is, by contrast, extremely suitable for mechanical compaction processes with pressures up to 200 MPa, which increase its packing density, its catalytic activity, and preserve porosity, flexibility and water stability, characteristics of STAM-17-OEt. The results are supported by many experimental techniques including EPR spectroscopy, PXRD diffraction, CO2 isotherms studies and catalytic tests.Publisher PDFPeer reviewe

    Monitoring the assembly-disassembly-organisation-reassembly process of germanosilicate UTL through in situ pair distribution function analysis

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    The authors would like to thank: The EPSRC (grants: EP/K025112/1; EP/K005499/1; EP/K503162/1) for funding opportunities and beam line I15 at the Diamond Light Source. Phoebe Allan is acknowledged for her help and knowledge of PDF refinement. M.M. and R.E.M. would like to acknowledge OP VVV "Excellent Research Teams", project No. CZ.02.1.01/0.0/0.0/15_003/0000417 - CUCAM.A study into the disassembly and organisation steps of the ADOR process has been undertaken through in situ Pair Distribution Function (PDF) analysis. Three aqueous systems (water, 6 M HCl and 12 M HCl) were introduced to a parent zeolite germanosilicate UTL in a cell. Hydrolysis could be clearly seen when UTL was exposed to water over a period of 8 hr, forming the disorded layered material, IPC-1P. In hydrochloric acid, the hydrolysis step is too quick to observe and a Ge-Cl containing species could be seen. In 6 M HCl, the rearrangement of the interlayer region began after an induction period of 8 hr, with the process still occuring after 15 hr. In 12 M HCl, the rearrangement appears to have come to an end after only 6 hr.PostprintPeer reviewe

    ZANATLIJE U SPLITU POČETKOM XVIII STOLJEĆA

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    The authors would like to acknowledge the financial support from the EPSRC industrial CASE award (grant EP/N50936X/1).Here we demonstrate the synthesis and structural characterisation of a novel copper MOF: STAM-NMe2, developed using the linker 5-dimethylamino isophthalic acid. The material is a member of the STAM series of MOFs, with a Kagome lattice structure and contains two types of pore system. The structure was investigated using single crystal X-ray diffraction, variable temperature powder X-ray diffraction was used to determine the thermal stability of the MOF, and nitrogen BET adsorption was employed to determine the porosity of the material.PostprintPeer reviewe

    Of less known literary work of Ivan Golub before the 1990s

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    Kronologija objavljivanja književnih djela svećenika, književnika i znanstvenika Ivana Goluba sugerira da se, osim rijetkih izuzetaka iz ranijeg razdoblja, književnim stvaralaštvom intenzivnije počeo baviti tek 1990-ih godina. No, kada u obzir uzmemo do danas uglavnom nepoznata njegova djela koja su nastala znatno prije, ali su objavljena tek 1990-ih godina, i to vjerojatno prije svega zahvaljujući slomu komunističkog društveno-političkog poretka koji je do tada proskribirao književnost kršćanskog nadahnuća, postaje jasno da se Golub književnim stvaralaštvom u kontinuitetu i otprilike jednakim intenzitetom ustvari bavio još od 1970-ih pa sve do danas.The order in which literary works by Ivan Golub, a Croatian priest, author and scientist, were published suggests, with some rare exceptions early on, that he started writing intensely only after the 1990s. However, we should take into consideration his works that are mostly unknown today and were created well before, but published only in the 1990s. That is probably because of the collapse of the communist socio-political order, which had prohibited literature of Christian inspiration up until then. It then becomes clear that Golub has been writing with the same intensity ever since the 1970s and to this day

    Melting of hybrid organic-inorganic perovskites.

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    Several organic-inorganic hybrid materials from the metal-organic framework (MOF) family have been shown to form stable liquids at high temperatures. Quenching then results in the formation of melt-quenched MOF glasses that retain the three-dimensional coordination bonding of the crystalline phase. These hybrid glasses have intriguing properties and could find practical applications, yet the melt-quench phenomenon has so far remained limited to a few MOF structures. Here we turn to hybrid organic-inorganic perovskites-which occupy a prominent position within materials chemistry owing to their functional properties such as ion transport, photoconductivity, ferroelectricity and multiferroicity-and show that a series of dicyanamide-based hybrid organic-inorganic perovskites undergo melting. Our combined experimental-computational approach demonstrates that, on quenching, they form glasses that largely retain their solid-state inorganic-organic connectivity. The resulting materials show very low thermal conductivities (~0.2 W m-1 K-1), moderate electrical conductivities (10-3-10-5 S m-1) and polymer-like thermomechanical properties

    Interfacial Bonding between a Crystalline Metal-Organic Framework and an Inorganic Glass.

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    The interface within a composite is critically important for the chemical and physical properties of these materials. However, experimental structural studies of the interfacial regions within metal-organic framework (MOF) composites are extremely challenging. Here, we provide the first example of a new MOF composite family, i.e., using an inorganic glass matrix host in place of the commonly used organic polymers. Crucially, we also decipher atom-atom interactions at the interface. In particular, we dispersed a zeolitic imidazolate framework (ZIF-8) within a phosphate glass matrix and identified interactions at the interface using several different analysis methods of pair distribution function and multinuclear multidimensional magic angle spinning nuclear magnetic resonance spectroscopy. These demonstrated glass-ZIF atom-atom correlations. Additionally, carbon dioxide uptake and stability tests were also performed to check the increment of the surface area and the stability and durability of the material in different media. This opens up possibilities for creating new composites that include the intrinsic chemical properties of the constituent MOFs and inorganic glasses

    Hydrolytic stability in hemilabile metal–organic frameworks

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    Highly porous metal–organic frameworks (MOFs), which have undergone exciting developments over the past few decades, show promise for a wide range of applications. However, many studies indicate that they suffer from significant stability issues, especially with respect to their interactions with water, which severely limits their practical potential. Here we demonstrate how the presence of ‘sacrificial’ bonds in the coordination environment of its metal centres (referred to as hemilability) endows a dehydrated copper-based MOF with good hydrolytic stability. On exposure to water, in contrast to the indiscriminate breaking of coordination bonds that typically results in structure degradation, it is non-structural weak interactions between the MOF’s copper paddlewheel clusters that are broken and the framework recovers its as-synthesized, hydrated structure. This MOF retained its structural integrity even after contact with water for one year, whereas HKUST-1, a compositionally similar material that lacks these sacrificial bonds, loses its crystallinity in less than a day under the same conditions

    Diet-Derived Metabolites and Mucus Link the Gut Microbiome to Fever After Cytotoxic Cancer Treatment

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    Not all patients with cancer and severe neutropenia develop fever, and the fecal microbiome may play a role. In a single-center study of patients undergoing hematopoietic cell transplant (n = 119), the fecal microbiome was characterized at onset of severe neutropenia. A total of 63 patients (53%) developed a subsequent fever, and their fecal microbiome displayed increased relative abundances of Akkermansia muciniphila, a species of mucin-degrading bacteria (P = 0.006, corrected for multiple comparisons). Two therapies that induce neutropenia, irradiation and melphalan, similarly expanded A. muciniphila and additionally thinned the colonic mucus layer in mice. Caloric restriction of unirradiated mice also expanded A. muciniphila and thinned the colonic mucus layer. Antibiotic treatment to eradicate A. muciniphila before caloric restriction preserved colonic mucus, whereas A. muciniphila reintroduction restored mucus thinning. Caloric restriction of unirradiated mice raised colonic luminal pH and reduced acetate, propionate, and butyrate. Culturing A. muciniphila in vitro with propionate reduced utilization of mucin as well as of fucose. Treating irradiated mice with an antibiotic targeting A. muciniphila or propionate preserved the mucus layer, suppressed translocation of flagellin, reduced inflammatory cytokines in the colon, and improved thermoregulation. These results suggest that diet, metabolites, and colonic mucus link the microbiome to neutropenic fever and may guide future microbiome-based preventive strategies

    Diet-Derived Metabolites and Mucus Link the Gut Microbiome to Fever After Cytotoxic Cancer Treatment

    Get PDF
    Not all patients with cancer and severe neutropenia develop fever, and the fecal microbiome may play a role. In a single-center study of patients undergoing hematopoietic cell transplant (n = 119), the fecal microbiome was characterized at onset of severe neutropenia. A total of 63 patients (53%) developed a subsequent fever, and their fecal microbiome displayed increased relative abundances of Akkermansia muciniphila, a species of mucin-degrading bacteria (P = 0.006, corrected for multiple comparisons). Two therapies that induce neutropenia, irradiation and melphalan, similarly expanded A. muciniphila and additionally thinned the colonic mucus layer in mice. Caloric restriction of unirradiated mice also expanded A. muciniphila and thinned the colonic mucus layer. Antibiotic treatment to eradicate A. muciniphila before caloric restriction preserved colonic mucus, whereas A. muciniphila reintroduction restored mucus thinning. Caloric restriction of unirradiated mice raised colonic luminal pH and reduced acetate, propionate, and butyrate. Culturing A. muciniphila in vitro with propionate reduced utilization of mucin as well as of fucose. Treating irradiated mice with an antibiotic targeting A. muciniphila or propionate preserved the mucus layer, suppressed translocation of flagellin, reduced inflammatory cytokines in the colon, and improved thermoregulation. These results suggest that diet, metabolites, and colonic mucus link the microbiome to neutropenic fever and may guide future microbiome-based preventive strategies
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