A Versatile Shaping Method of Very-High Loading Porous Solids Paper Adsorbent Composites.

Owing to their high porosity and tunability, porous solids such as metal-organic frameworks (MOFs), zeolites, or activated carbons (ACs) are of great interest in the fields of air purification, gas separation, and catalysis, among others. Nonetheless, these materials are usually synthetized as powders and need to be shaped in a more practical way that does not modify their intrinsic property (i.e., porosity). Elaborating porous, freestanding and flexible sheets is a relevant shaping strategy. However, when high loadings (>70 wt.%) are achieved the mechanical properties are challenged. A new straightforward and green method involving the combination softwood bleached kraft pulp fibers (S) and nano-fibrillated cellulose (NFC) is reported, where S provides flexibility while NFC acts as a micro-structuring and mechanical reinforcement agent to form high loadings porous solids paper sheets (>70 wt.%). The composite has unobstructed porosity and good mechanical strength. The sheets prepared with various fillers (MOFs, ACs, and zeolites) can be rolled, handled, and adapted to different uses, such as air purification. As an example of potential application, a MOF paper composite has been considered for the capture of polar volatile organic compounds exhibiting better performance than beads and granules.

Detangling electrolyte chemical dynamics in lithium sulfur batteries by operando monitoring with optical resonance combs.

Challenges in enabling next-generation rechargeable batteries with lower cost, higher energy density, and longer cycling life stem not only from combining appropriate materials, but from optimally using cell components. One-size-fits-all approaches to operational cycling and monitoring are limited in improving sustainability if they cannot utilize and capture essential chemical dynamics and states of electrodes and electrolytes. Herein we describe and show how the use of tilted fiber Bragg grating (TFBG) sensors to track, via the monitoring of both temperature and refractive index metrics, electrolyte-electrode coupled changes that fundamentally control lithium sulfur batteries. Through quantitative sensing of the sulfur concentration in the electrolyte, we demonstrate that the nucleation pathway and crystallization of Li2S and sulfur govern the cycling performance. With this technique, a critical milestone is achieved, not only towards developing chemistry-wise cells (in terms of smart battery sensing leading to improved safety and health diagnostics), but further towards demonstrating that the coupling of sensing and cycling can revitalize known cell chemistries and break open new directions for their development.

In-house fabrication of 1.3 to 7 mm MAS drive caps using desktop 3D printers.

The 3D-printing technology has emerged as a well-developed method to produce parts with considerably low cost and yet with high precision (<100 µm). Recent literature has shown that the 3D-printing technology can be exploited to fabricate a magic-angle spinning (MAS) system in solid-state nuclear magnetic resonance (NMR) spectroscopy. In particular, it was demonstrated that advanced industry-grade 3D printers could fabricate 3.2 mm MAS drive caps with intricate features, and the caps were shown to spin > 20 kHz. Here, we show that not only lab-affordable benchtop 3D printers can produce 3.2 mm drive caps with a similar quality as the commercialized version, but also smaller 2.5 mm and 1.3 mm MAS drive caps-despite a slight compromise in performance. All in-house fabricated drive caps (1.3 to 7 mm) can be consistently reproduced (>90 %) and achieve excellent spinning performances. In summary, the > 3.2 mm systems have similar performances as the commercial systems, while the 2.5- and 1.3-mm caps can spin up to 26 kHz ± 2 Hz, and 46 kHz ± 1 Hz, respectively. The low-cost and fast in-house fabrication of MAS drive caps allows easy prototyping of new MAS drive cap models and, possibly, new NMR applications. For instance, we have fabricated a 4 mm drive cap with a center hole that could allow better light penetration or sample insertion during MAS. Besides, an added groove design on the drive cap allows an airtight seal suitable for probing air- or moisture-sensitive materials. Moreover, the 3D-printed cap was shown to be robust for low-temperature MAS experiments at âˆ¼ 100 K, making it suitable for DNP experiments.

CLEC5A expression can be triggered by spike glycoprotein and may be a potential target for COVID-19 therapy.

The immune response is crucial for coronavirus disease 19 (COVID-19) progression, with the participation of proinflammatory cells and cytokines, inducing lung injury and loss of respiratory function. CLEC5A expression on monocytes can be triggered by viral and bacterial infections, leading to poor outcomes. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is able to induce neutrophil activation by CLEC5A and Toll-like receptor 2, leading to an aggressive inflammatory cascade, but little is known about the molecular interactions between CLEC5A and SARS-CoV-2 proteins. Here, we aimed to explore how CLEC5A expression could be affected by SARS-CoV-2 infection using immunological tools with in vitro, in vivo, and in silico assays. The findings revealed that high levels of CLEC5A expression were found in monocytes from severe COVID-19 patients in comparison with mild COVID-19 and unexposed subjects, but not in vaccinated subjects who developed mild COVID-19. In hamsters, we detected CLEC5A gene expression during 3-15 days of Omicron strain viral challenge. Our results also showed that CLEC5A can interact with SARS-CoV-2, promoting inflammatory cytokine production, probably through an interaction with the receptor-binding domain in the N-acetylglucosamine binding site (NAG-601). The high expression of CLEC5A and high levels of proinflammatory cytokine production were reduced in vitro by a human CLEC5A monoclonal antibody. Finally, CLEC5A was triggered by spike glycoprotein, suggesting its involvement in COVID-19 progression; therapy with a monoclonal antibody could be a good strategy for COVID-19 treatment, but vaccines are still the best option to avoid hospitalization/deaths.

MOFs with Open Metal(III) Sites for the Environmental Capture of Polar Volatile Organic Compounds.

Metal-Organic Frameworks (MOFs) with open metal sites (OMS) interact strongly with a range of polar gases/vapors. However, under ambient conditions, their selective adsorption is generally impaired due to a high OMS affinity to water. This led previously to the privilege selection of hydrophobic MOFs for the selective capture/detection of volatile organic compounds (VOCs). Herein, we show that this paradigm is challenged by metal(III) polycarboxylates MOFs, bearing a high concentration of OMS, as MIL-100(Fe), enabling the selective capture of polar VOCs even in the presence of water. With experimental and computational tools, including single-component gravimetric and dynamic mixture adsorption measurements, in situ infrared (IR) spectroscopy and Density Functional Theory calculations we reveal that this adsorption mechanism involves a direct coordination of the VOC on the OMS, associated with an interaction energy that exceeds that of water. Hence, MOFs with OMS are demonstrated to be of interest for air purification purposes.

MIL-53 Metal-Organic Framework as a Flexible Cathode for Lithium-Oxygen Batteries.

Li-air batteries possess higher specific energies than the current Li-ion batteries. Major drawbacks of the air cathode include the sluggish kinetics of the oxygen reduction (OER), high overpotentials and pore clogging during discharge processes. Metal-Organic Frameworks (MOFs) appear as promising materials because of their high surface areas, tailorable pore sizes and catalytic centers. In this work, we propose to use, for the first time, aluminum terephthalate (well known as MIL-53) as a flexible air cathode for Li-O2 batteries. This compound was synthetized through hydrothermal and microwave-assisted routes, leading to different particle sizes with different aspect ratios. The electrochemical properties of both materials seem to be equivalent. Several behaviors are observed depending on the initial value of the first discharge capacity. When the first discharge capacity is higher, no OER occurs, leading to a fast decrease in the capacity during cycling. The nature and the morphology of the discharge products are investigated using ex situ analysis (XRD, SEM and XPS). For both MIL-53 materials, lithium peroxide Li2O2 is found as the main discharge product. A morphological evolution of the Li2O2 particles occurs upon cycling (stacked thin plates, toroids or pseudo-spheres).

Conversion of a microwave synthesized alkali-metal MOF to a carbonaceous anode for Li-ion batteries.

Hierarchical carbon-rich materials have shown immense potential for various electrochemical applications. Metal-organic frameworks (MOFs) are well suited precursors for obtaining such templated carbon matrices. Usually these conversions are carried out by energy intensive processes and lead to the presence of toxic transition metal residues. Herein, we demonstrate the green, scalable, microwave-assisted synthesis of a three-dimensional s-block metal based MOF and its efficient transformation into a carbonaceous material. The MOF-derived solid functions as a negative electrode for lithium-ion batteries having moderate low-rate capacities and cycling stability.

Sodium Naphthalene-2,6-dicarboxylate: An Anode for Sodium Batteries.

The conjugated dicarboxylate sodium naphthalene-2,6-dicarboxylate (Na2 NDC) was prepared by a low-energy-consumption reflux method, and its performance as a negative electrode for sodium-ion batteries was evaluated in electrochemical cells. The structure of Na2 NDC was solved for the first time (monoclinic P21 /c) from powder XRD data and consists of π-stacked naphthalene units separated by sodium-oxygen layers. Through an appropriate choice of binder and conducting carbon additive, Na2 NDC exhibited a reversible two electron sodium insertion at approximately 0.4 V (vs. Na+ /Na) with remarkably stable capacities of approximately 200 mAh g-1 at a rate of C/2 and good rate capability (≈133 mAh g-1 at 5 C). In parallel, the high thermal stability of the material was demonstrated by high-temperature XRD: the framework remained intact to above 500 °C.

Phosphate Ion Functionalization of Perovskite Surfaces for Enhanced Oxygen Evolution Reaction.

Recent findings revealed that surface oxygen can participate in the oxygen evolution reaction (OER) for the most active catalysts, which eventually triggers a new mechanism for which the deprotonation of surface intermediates limits the OER activity. We propose in this work a "dual strategy" in which tuning the electronic properties of the oxide, such as La1-xSrxCoO3-δ, can be dissociated from the use of surface functionalization with phosphate ion groups (Pi) that enhances the interfacial proton transfer. Results show that the Pi functionalized La0.5Sr0.5CoO3-δ gives rise to a significant enhancement of the OER activity when compared to La0.5Sr0.5CoO3-δ and LaCoO3. We further demonstrate that the Pi surface functionalization selectivity enhances the activity when the OER kinetics is limited by the proton transfer. Finally, this work suggests that tuning the catalytic activity by such a "dual approach" may be a new and largely unexplored avenue for the design of novel high-performance catalysts.

Glycerol carbonate in Ferrier reaction: Access to new enantiopure building blocks to develop glycoglycerolipid analogues.

Glycerol carbonate and tri-O-acetyl-D-glucal were used for the synthesis of glycero-functionalized carbohydrates. Ferrier reaction between the two partners afforded the O-glucoside in 84% yield. Spontaneous crystallization yielded 28% of a pure diastereoisomer with the S configuration as determined by X-ray crystallography. Then, the azido-glycerosugar was prepared in two steps: ring opening of the cyclic carbonate with sodium azide and per-acetylation with an excellent yield of 94%. A library of glycoconjugates were prepared using a 1,3-dipolar cycloaddition in yields ranging from 64 to 99%.

New iron tetrazolate frameworks: synthesis, temperature effect, thermal behaviour, Mössbauer and magnetic studies.

The exploration of the FeF3/FeF2-Hamtetraz-HF system in dimethylformamide by solvothermal synthesis evidences two isostructural 3D hybrid fluoroferrates. They are prepared from the same starting mixture at two different synthesis temperatures: 120 °C for [Hdma]·(Fe4(II)Fe(III)F8(H2O)2(amtetraz)4) () and 140 °C for [Hdma]1.5·(Fe4.5(II)Fe0.5(III)F7(H2O)(HCOO)(amtetraz)4) (). Both compounds are characterized by single crystal X-ray diffraction, X-ray thermodiffraction, TGA analysis, Mössbauer spectrometry and SQUID magnetometry. They crystallize in the monoclinic system and are built from two distinct chains connected by aminotetrazolate anions. The first chain ∞(Fe(II)FN4) is common to and and can be found in numerous fluorides. In the second chain ∞(Fe3X12) (X = F, N, O), iron cations adopt both valence states Fe(ii)/Fe(iii). The hydrolysis of DMF implies the formation of a [Hdma](+) cation and a (HCOO)(-) anion. The presence of Fe(3+) in both phases is evidenced by (57)Fe Mössbauer spectrometry. The magnetic properties are studied and two transitions from a paramagnetic regime to a long range ordered state below 30 K and 5 K are identified.

Towards a non-invasive quantitative analysis of the organic components in museum objects varnishes by vibrational spectroscopies: methodological approach.

The compositions of ancient varnishes are mainly determined destructively by separation methods coupled to mass spectrometry. In this study, a methodology for non-invasive quantitative analyses of varnishes by vibrational spectroscopies is proposed. For that, experimental simplified varnishes of colophony and linseed oil were prepared according to 18th century traditional recipes with an increasing mass concentration ratio of colophony/linseed oil. FT-Raman and IR analyses using ATR and non-invasive reflectance modes were done on the "pure" materials and on the different mixtures. Then, a new approach involving spectral decomposition calculation was developed considering the mixture spectra as a linear combination of the pure materials ones, and giving a relative amount of each component. Specific spectral regions were treated and the obtained results show a good accuracy between the prepared and calculated amounts of the two compounds. We were thus able to detect and quantify from 10% to 50% of colophony in linseed oil using non-invasive techniques that can also be conducted in situ with portable instruments when it comes to museum varnished objects and artifacts.

New series of hybrid fluoroferrates synthesized with triazoles: various dimensionalities and Mössbauer studies.

The solvothermal reactions of an equimolar mixture of FeF2 and FeF3 with Htaz (1,2,4-triazole), aqueous HF and DMF (dimethylformamide) at 120 °C yielded a series of new hybrid fluoroferrates (1-5). Their structures were characterized by either single crystal or powder X-ray diffraction data analysis. Both classes of hybrid networks were observed according to the Fe(n+)/Htaz/HF starting ratio: class I for 1 and 2 and class II for 3, 4 and 5. Four compounds, [Hdma]·(Fe2(H2O)4F6) (1), [Hdma]·(Fe2(H2O)4F6)·0.5H2O (2), Fe2F5(Htaz) (3) and [Hdma]·(Fe2F5(H2O)(Htaz)(taz)) (4), exhibit both Fe(II) and Fe(III) oxidation states while [Hdma]·(Fe2F5(taz)2) (5) contains only Fe(III) cations. [Hdma]·(Fe2(H2O)4F6) (1) and [Hdma]·(Fe2(H2O)4F6)·0.5H2O (2) contain anionic inorganic chains of alternating corner-sharing Fe(II) and Fe(III) octahedra; they are weakly hydrogen bonded to dimethylammonium cations [Hdma](+) which are formed by the in situ hydrolysis of DMF. The structure of Fe2F5(Htaz) (3) exhibits a three dimensional inorganic network resulting from the association of HTB planes of corner sharing Fe(II)F4N2 and Fe(III)F6 octahedra. [Hdma]·(Fe2F5(H2O)(Htaz)(taz)) (4) and [Hdma]·(Fe2F5(taz)2) (5) reveal two original two-dimensional sheets. In 4, the deprotonated and neutral amines connect trinuclear Fe3F10N6 units of corner-sharing octahedra and mononuclear FeN4(H2O)2 octahedra. Infinite Fe2F5(taz)2 layers in 5 are built up from dinuclear species connected by deprotonated amines along two perpendicular directions. The thermal behavior and Mössbauer spectrometry results are detailed for the first tridimensional mixed valence hybrid fluoroferrate (3).