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Separation of volatile organic compounds is one of the most studied processes in industry. TAMOF-1 is a homochiral metal-organic framework with a crystalline network of interconnected 1 nm channels and has high thermal and chemical stability. Thanks to these features, it can resolve racemic mixtures of chiral drugs as a chiral stationary phase in chromatography. Interestingly, the particular shape and size of its channels, along with the presence of metallic centers and functional groups, allow establishing weak but significant interactions with guest molecules. This opens interesting possibilities not only to resolve racemates but also to separate other organic mixtures, such as saturated/unsaturated and/or linear/branched molecules. In search of these applications, we have studied the separation of volatile organic compounds in TAMOF-1. Monte Carlo simulations in the grand-canonical ensemble have been carried out to evaluate the separation of the selected molecules. Our results predict that TAMOF-1 is able to separate xylene isomers, hexane isomers, and benzene-cyclohexane mixtures. Experimental breakthrough analysis in the gas phase and also in the liquid phase confirms these predictions. Beds of TAMOF-1 are able to recognize the substitution in xylenes and the branching in hexanes, yielding excellent separation and reproducibility, thanks to the chemical and mechanical features of this material., Universidad Pablo de Olavide. Departamento de Sistemas Físicos, Químicos y Naturales

Cobalt hexacyanoferrate, the Co–Fe Prussian blue derivative (CoFePB), is an effective, selective and stable electrocatalyst for formate oxidation, exhibiting robust performance under a variety of electrolyte conditions. In this work, we test CoFePB as a non-noble-metal formate oxidation catalyst in a liquid fuel cell, with formate acting as a carbon-based, water soluble, hydrogen carrier. Herein we fabricate two proof-of-concept aqueous direct formate fuel cells. One uses CoFePB as a formic acid oxidation catalyst coupled with Pt as an oxygen reduction reaction catalyst and delivers a maximum power density of 67 μW cm−2. The second one, based on carbon felt as a cathode and Ce4+ as a terminal electron acceptor, shows a stable maximum power output of 8.6 mW cm−2. This is, to our knowledge, the first example of a noble-metal-free direct formate oxidation fuel cell.

Mechanical reinforcement of proton exchange membranes is a great challenge allowing the reduction of their thickness, with the advantages of lower resistance, improved water transport, decreased fuel crossover and high durability, which are crucial for fuel cells. We describe herein a new class of reinforced membranes based on nanofibers of polysulfone (PSU) functionalized with 4-heptyl-1,2,3-triazole (PSUT) likely interacting via hydrogen bonds or ionic cross-linking with a short-side-chain type perfluorosulfonic acid (Aquivion®) matrix. PSUT with two functionalization degrees was electrospun into webs which were impregnated with Aquivion® to afford composite membranes that presented higher dimensional stability in water, increased mechanical strength and Young modulus in comparison to reinforced membranes of non-functionalized PSU and pristine ionomer membrane, without any decrease in proton conductivity. Membrane-electrode assemblies incorporating an Aquivion® membrane reinforced with PSUT exhibited 5 times superior durability than those with a pristine Aquivion® membrane without any radical scavenger. These features may be ascribed to the specific interaction between basic fibers and acidic ionomer. The incorporation of webs of active fibers in ionomer membranes is an effective strategy of reinforcement leading to high performance and increased durability, which can be extended to other kinds of ion exchange membranes and devices.

Nanocomposite membranes based on electrospun polysulfone fibre web and short-side-chain Aquivion® perfluorosulfonic acid have been prepared for application in proton exchange membrane water electrolysis. The nanocomposite membranes showed improved mechanical properties and dimensional stability with respect to their non-reinforced counterparts even at low fibre content (5 wt%) maintaining high proton conductivity. The composite membranes prepared with Aquivion® with EW of 830 g eq−1 are suitable for water electrolysis: in particular the I-V curve given by a membrane electrode assembly comprising the reinforced membrane was similar to that obtained with a non-modified one. Moreover, the nanofibrous polymer component was effective in lowering hydrogen crossover at differential pressures of 0.25 MPa.

Nanocomposite proton exchange membranes based on fibrous sulfonated poly(ether ether ketone) (sPEEK) and Aquivion ® have been prepared by a two-step procedure involving electrospinning and impregnation. The dependence of their proton conductivity, water uptake, dimensional swelling and mechanical strength on the sulfonation degree of the sPEEK fibers has been determined and compared to a pristine Aquivion ® membrane. The preparation of a composite membrane where a highly sulfonated PEEK mat is crosslinked previous to Aquivion ® impregnation was also investigated. In all cases, the composite membranes demonstrate a diminution in proton conductivity compared to the non-reinforced membrane, but enhanced mechanical properties and dimensional stability. In particular, the system comprising crosslinked sPEEK presented the best mechanical and swelling behaviors with a lower conductivity loss.

Complexes [Cp*Ir(ppy)NO3] (ppy = 2-phenylpyridine, 1), [Cp*Ir(2′,4′-F2-ppy)NO3] (2b), [Cp*Ir(κ2-C2,C2′-NHC)Cl], (κ2-C2,C2′-NHC = κ2-C2,C2′-1,3-bis(4-(N,N-dimethylamino)phenyl)-imidazol-2-ylidene, 3), [Cp*Ir(bpyr)(SOMe2)] (bpyr = bis-diethyl-pyrrole, 4), [Cp*Ir(bimH2)Cl]Cl (bimH2 = 2,2′-bisimidazole, 5) and [Cp*IrCl(μ2-κ2-κ1-bimH)IrCl2Cp*] (6) have been synthesized and characterized in solution by multinuclear and multidimensional NMR spectroscopy. The structures in the solid state of 3 and 6 have been determined by means of single-crystal diffraction X-Ray studies. Complexes 1–6 were found to be effective catalysts for water oxidation to molecular oxygen driven by cerium ammonium nitrate. The highest activity was observed for 4 (TOFmax = 12 min−1, TON > 500), 5 (TOFmax = 23 min−1, TON > 500) and 6 (TOFmax = 51 min−1, TON > 500) bearing more electron-donating ligands.

Purpose The aim was to calibrate gamma cameras in the framework of the Italian multicentre study for lesion dosimetry in 223Ra therapy of bone metastases. Equipments of several manufacturers and different models were used. Methods Eleven gamma cameras (3/8- and 5/8-inch crystal) were used, acquiring planar static images with double-peak (82 and 154 keV, 20% wide) and MEGP collimator. The sensitivity was measured in air, varying source-detector distance and source size. Transmission curves were measured, calculating the parameters used for attenuation/scatter correction with the pseudo-extrapolation number method, and assessing their variations with the source size. Results Values of the calibration factor (geometric mean of both detector sensitivities) ranged from 41.1 to 113.9 cps/MBq. For the smallest source (diameter of 3.5 cm), the calibration factor decrease ranged from −30% to −4%, highlighting the importance of partial volume effects according to the equipment involved. The sensitivity variation with the source-detector distance, with respect to the 15 cm-value, reached 10% (in absolute value) in the range 5–30 cm, but fixing the distance between the two heads, the calibration factor variation with the distance from the midline was within 3.6%. Appreciable variation of the transmission curves with the source size were observed, examining the results obtained with six gamma cameras. Conclusion Assessments of sensitivity and transmission curve variations with source size should be regularly implemented in calibration procedures. The results of this study represent a useful compendium to check the obtained calibrations for dosimetric purposes.

The aim was to calibrate gamma cameras in the framework of the Italian multicentre study for lesion dosimetry inEleven gamma cameras (3/8- and 5/8-inch crystal) were used, acquiring planar static images with double-peak (82 and 154keV, 20% wide) and MEGP collimator. The sensitivity was measured in air, varying source-detector distance and source size. Transmission curves were measured, calculating the parameters used for attenuation/scatter correction with the pseudo-extrapolation number method, and assessing their variations with the source size.Values of the calibration factor (geometric mean of both detector sensitivities) ranged from 41.1 to 113.9cps/MBq. For the smallest source (diameter of 3.5cm), the calibration factor decrease ranged from -30% to -4%, highlighting the importance of partial volume effects according to the equipment involved. The sensitivity variation with the source-detector distance, with respect to the 15cm-value, reached 10% (in absolute value) in the range 5-30cm, but fixing the distance between the two heads, the calibration factor variation with the distance from the midline was within 3.6%. Appreciable variation of the transmission curves with the source size were observed, examining the results obtained with six gamma cameras.Assessments of sensitivity and transmission curve variations with source size should be regularly implemented in calibration procedures. The results of this study represent a useful compendium to check the obtained calibrations for dosimetric purposes.

The aims of this work were to explore patient eligibility criteria for dosimetric studies inCalibrations withSensitivity was nearly constant varying activity and distance (maximum s.d.=2%). Partial volume effects were negligible for object area ⩾960mmThe minimum calibration protocol requires sensitivity and transmission curve measurements varying the object size, performing a careful procedure standardisation. Lesions with

International audience; Microwave heating holds all the aces regarding development of effective and environment-friendly methods to perform chemical transformations. Coupling the benefits of microwave-enhanced chemistry with highly reliable copper-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry paves the way for a rapid and efficient synthesis procedure to afford high-performance thermoplastic materials. We describe herein fast and high-yielding synthesis of 1,2,3-triazole functionalized polysulfone through microwave-assisted CuAAC as well as explore their potential as phosphoric acid doped polymer electrolyte membranes (PEM) for high temperature PEM fuel cells. Polymers with various degrees of substitution of the side-chain functionality of 1,4-substituted 1,2,3-triazole with alkyl and aryl pendant structures are prepared by sequential chloromethylation, azidation and microwave-assisted CuAAC using a range of alkynes (1-pentyne, 1-nonyne and phenylacetylene). The completeness of reaction at each step as well as the purity of the clicked polymers were confirmed by 1 H-13 C NMR, DOSY-NMR and FTIR-ATR spectroscopies. The thermal and thermo-chemical properties of the modified polymers were characterized by differential scanning calorimetry and thermogravimetric analysis coupled with mass spec-troscopy (TG-MS) respectively. TG-MS analysis demonstrated that the commencement of the thermal degradation takes place with the decomposition of the triazole ring while its substituents have critical influence on the initiation temperature. Polysulfone functionalized with 4-phenyl-1,2,3-triazole demonstrate significantly higher Tg, Td and elastic modulus than the ones bearing 4-propyl-1,2,3-triazole and 4-heptyl-1,2,3-triazole groups. After doping with phosphoric acid, the functional-ized polymers with ADL of 5 show promising performance with high proton conductivity in anhydrous conditions (in the range of 27-35 mS/cm) and satisfactorily high elastic modulus (in the range of 332-349 MPa).

Purpose The aims of this work were to explore patient eligibility criteria for dosimetric studies in 223 Ra therapy and evaluate the effects of differences in gamma camera calibration procedures into activity quantification. Methods Calibrations with 223 Ra were performed with four gamma cameras (3/8-inch crystal) acquiring planar static images with double-peak (82 and 154 keV, 20% wide) and MEGP collimator. The sensitivity was measured in air by varying activity, source-detector distance, and source diameter. Transmission curves were measured for attenuation/scatter correction with the pseudo-extrapolation number method, varying the experimental setup. 223 Ra images of twenty-five patients (69 lesions) were acquired to study the lesions visibility. Univariate ROC analysis was performed considering visible/non visible lesions on 223 Ra images as true positive/true negative group, and using as score value the lesion/soft tissue contrast ratio (CR) derived from 99m Tc-MDP WB scan. Results Sensitivity was nearly constant varying activity and distance (maximum s.d. = 2%). Partial volume effects were negligible for object area ⩾960 mm 2 . Transmission curve measurements are affected by experimental setup and source size, leading to activity quantification errors up to 20%. The ROC analysis yielded an AUC of 0.972 and an optimal threshold of CR of 10, corresponding to an accuracy of 92%. Conclusion The minimum calibration protocol requires sensitivity and transmission curve measurements varying the object size, performing a careful procedure standardisation. Lesions with 99m Tc-MDP CR higher than 10, not overlapping the GI tract, are generally visible on 223 Ra images acquired at 24 h after the administration, and possibly eligible for dosimetric studies.

In order to have a better understanding of Nafion behavior in fuel cells operating at temperatures higher than 80 °C, the preparation of membranes containing a large amount of layered morphologies ...

The 1,2,3-triazole functionality demonstrates high chemical stability towards severe hydrolytic, oxidizing, and reducing conditions, even at elevated temperatures. Furthermore together with aromatic character and ability to form hydrogen bonds, it is reported to possess anti-oxidant properties1. All these features make polymers functionalized with 1,2,3-triazole of interest in proton exchange membranes as reinforcement or matrix for application in low and high temperature fuel cells. We will describe a fast and high-yielding synthesis of 1,2,3-triazole functionalized polysulfone through microwave-assisted copper-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry. Polymers with various degrees of substitution of the side-chain functionality of 1,4-substituted 1,2,3-triazole with alkyl and aryl pendant structures were prepared and characterized to assess the completeness of the reaction. The thermal and thermo-chemical properties of the modified polymers were also characterized. In one approach, cast membranes of 1,2,3-triazole functionalized polysulfone were doped with phosphoric acid for application in HT-PEMFC and their properties compared with conventional polybenzimidazole based systems. These novel membranes presented promising performance with high proton conductivity in anhydrous conditions and satisfactorily high elastic modulus2. In another strategy with targeted low temperature PEMFC applications, nanocomposite membranes were prepared based on functionalized polysulfone and a perfluorosulfonic acid ionomer. As already evidenced for PBI-PFSA composites3, the specific interaction between the basic triazole functionalized polymer and the acidic ionomer lead to electrolytes with improved mechanical properties and without significant loss in proton conductivity. 1. J. Totobenazara and A. J. Burke, Tetrahedron Lett., 56, 2853–2859 (2015). 2. R. Sood, A. Donnadio, S. Giancola, A. Kreisz, D.J. Jones, S. Cavaliere, ACS Appl. Mater. Interf., in press.