Highly Water-Stable Zirconium Metal-Organic Framework UiO-66 Membranes Supported on Alumina Hollow Fibers for Desalination

In this study, continuous zirconium(IV)-based metal-organic framework (Zr-MOF) membranes were prepared. The pure-phase Zr-MOF (i.e., UiO-66) polycrystalline membranes were fabricated on alumina hollow fibers using an in situ solvothermal synthesis method. Single-gas permeation and ion rejection tests were carried out to confirm membrane integrity and functionality. The membrane exhibited excellent multivalent ion rejection (e.g., 86.3% for Ca2+, 98.0% for Mg2+, and 99.3% for Al3+) on the basis of size exclusion with moderate permeance (0.14 L m-2 h-1 bar-1) and good permeability (0.28 L m-2 h-1 bar-1 μm). Benefiting from the exceptional chemical stability of the UiO-66 material, no degradation of membrane performance was observed for various tests up to 170 h toward a wide range of saline solutions. The high separation performance combined with its outstanding water stability suggests the developed UiO-66 membrane as a promising candidate for water desalination

Plasma proteins elevated in severe asthma despite oral steroid use and unrelated to Type-2 inflammation

Rationale Asthma phenotyping requires novel biomarker discovery. Objectives To identify plasma biomarkers associated with asthma phenotypes by application of a new proteomic panel to samples from two well-characterised cohorts of severe (SA) and mild-to-moderate (MMA) asthmatics, COPD subjects and healthy controls (HCs). Methods An antibody-based array targeting 177 proteins predominantly involved in pathways relevant to inflammation, lipid metabolism, signal transduction and extracellular matrix was applied to plasma from 525 asthmatics and HCs in the U-BIOPRED cohort, and 142 subjects with asthma and COPD from the validation cohort BIOAIR. Effects of oral corticosteroids (OCS) were determined by a 2-week, placebo-controlled OCS trial in BIOAIR, and confirmed by relation to objective OCS measures in U-BIOPRED. Results In U-BIOPRED, 110 proteins were significantly different, mostly elevated, in SA compared to MMA and HCs. 10 proteins were elevated in SA versus MMA in both U-BIOPRED and BIOAIR (alpha-1-antichymotrypsin, apolipoprotein-E, complement component 9, complement factor I, macrophage inflammatory protein-3, interleukin-6, sphingomyelin phosphodiesterase 3, TNF receptor superfamily member 11a, transforming growth factor-β and glutathione S-transferase). OCS treatment decreased most proteins, yet differences between SA and MMA remained following correction for OCS use. Consensus clustering of U-BIOPRED protein data yielded six clusters associated with asthma control, quality of life, blood neutrophils, high-sensitivity C-reactive protein and body mass index, but not Type-2 inflammatory biomarkers. The mast cell specific enzyme carboxypeptidase A3 was one major contributor to cluster differentiation. Conclusions The plasma proteomic panel revealed previously unexplored yet potentially useful Type-2independent biomarkers and validated several proteins with established involvement in the pathophysiology of SA

New investigations on the LGT crystal intended for time and frequency applications

cited By 0International audienceMaterials of the langasite family are of current interest for both Bulk Acoustic Wave and Surface Acoustic Wave devices. In particular, they could be promising solutions to Frequency and Time applications due to their g/product, two to three times higher than for the quartz crystal [1]. We have shown that this encouraging result is strongly linked to the crystal quality [2] and to the post thermal treatment which has been submitted the device. Among the numerous crystals belonging to the LGS family, LGT seems more interesting because of the best combination of quality of growth and material parameters [3, 4]. © 2010 IEEE

Cation mobility upon adsorption of methanol in NaY faujasite type zeolite: A molecular dynamics study compared to dielectric relaxation experiments

Molecular Dynamics simulations have been carried out to address the question of cation migration upon adsorption of methanol in NaY Faujasite system as a function of the loading. It has been shown that at low and intermediate loadings, SII cations can migrate toward the center of the supercage due strong interaction with the adsorbates, followed by hopping of SI' cations from the sodalite cage into the supercage to fill vacant SII sites. SI cations mainly remain trapped in their initial sites whatever the loading. At higher loading, only limited motion is observed for SII cations due to steric effects induced by the adsorbates within the supercage. These simulated results are in good agreement with those extracted by Complex Impedance Spectroscopy measurements, which provided the evolution of the number of extraframework cations in the different crystallographic sites as a function of the treatment temperature

Effect of water adsorption on ion dynamics in confined geometry: Na+ faujasites and homoionic alkali exchanged montmorillonite

International audienc

Computational Exploration of the Water Concentration Dependence of the Proton Transport in the Porous UiO-66(Zr)-(CO2H)(2) Metal-Organic Framework

SSCI-VIDE+ATARI+HJOInternational audienceThe UiO-66(Zr)-(CO2H)(2) metal-organic framework been recently revealed as a promising proton conducting material under humidification. Here, aMS-EVB3 molecular dynamics simulations are performed to reveal at the molecular level the structure, thermodynamics, and dynamics of the hydrated proton in three-dimensional (3D)-cages MOF as a function of the water loading. It is found that the most stable proton solvation structure corresponds to a H7O3+ cation and that a transition between this complex and a Zundel cation likely governs the proton transport in this MOF occurring via a Grotthuss-type mechanism. It is further shown that the formation of a H2O hydrogen-bonded bridge that connects the cages occurs only at high water concentration and this creates a path allowing the excess proton to jump from one cage to another. This leads to a faster self-diffusivity of proton at high water concentration, thereby supporting the increase of the proton conductivity with the water loading as experimentally evidenced