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Lignin as a precursor of a gel electrolyte and salt templated carbon for sustainable electrochemical capacitors
No full textInternational audienceElectrochemical capacitors (ECs) belong to attractive high-power devices; however, their key components often do not meet ecological requirements. Herein, we propose a sustainable EC based on a gel electrolyte and porous carbon, both of which are made from lignosulfonate (LS), a waste-derived technical lignin from wood. First, the uptake ability of the LS-based gel electrolyte was systematically investigated using several concentrations (1-24 m) of aqueous acetate salt solutions containing different cations (Li, Na, and K). An optimized aqueous electrolyte, 5 m KOAc, was selected due to the high ionic conductivity and ion mobility. Next, LS was converted into porous carbons through an environmentally friendly salt templating approach using NaOAc and KOAc, which enabled precise control of the carbon structure and texture. The resulting carbons exhibited predominantly microporous characteristics with specific surface areas ranging from 881 to 1754 m2 g-1. Raman spectroscopy analysis revealed various degrees of structural disorder (ID1 /IG ranged from 1.37 to 3.00). Finally, ECs were assembled with the LS-based gel electrolyte and salt templated carbons. They achieved a stable operating voltage (1.6 V), reduced self-discharge (loss of ∼30% of initial voltage), and a long lifespan (170 h of floating), which is competitive with reference aqueous ECs (loss of ∼40% of initial voltage and 120 h of floating). Importantly, the LS gel plays a two-in-one role as an electrolyte and a separator. The lack of electrolyte leakage also ensures safety of the device. To sum up, our study proved that water-soluble LS waste can be transformed into components of green energy storage systems
Des briques moléculaires indanones à partir de molécules plateforme C9 dérivées de la lignine
No full textInternational audienceLignin-based aryl 3-hydroxypropanones were converted into indanones via a domino dehydration/Nazarov cyclization in the presence of a superacid. The cyclization was studied in detail, and the resulting indanones were engaged in two postfunctionalizations: a reduction/elimination domino sequence and a ring expansion. Lastly, the method has been successfully applied to the synthesis of the anti-Alzheimer drug donepezil
Multidisciplinary science funding is more than ever a planetary priority: reflections from the Make Our Planet Great Again (MOPGA) program
No full textInternational audienceGlobal change poses “wicked problems” that have become ever more complex, pervasive, and damaging. Developing innovative solutions increasingly require diverse research approaches. The Franco-German Make Our Planet Great Again (MOPGA) program was designed to create a unique international network of top-level research, from fundamental to solution-oriented projects. MOPGA stands out from other large research initiatives by focusing not on a singular central research challenge but on facilitating multidisciplinary interactions between traditionally separated fields. MOPGA recognized that social, natural and engineering sciences share a unifying aim to address global change. In addition to addressing timely and innovative research questions within disciplines, MOPGA worked to improve communication across disciplines via annual meetings for all laureates and their research groups, scientific board exchanges, and public online seminars. Drawing on our MOPGA experiences, we discuss how such exchanges should be extended to meet the needs identified by the scientific community, international policy-makers, and regional stakeholders. In the current political landscape of scientific suppression and heightened mistrust in scientific expertise, the need for such bold, independent and collaborative scientific initiatives is greater than ever
Incorporation of Ruthenium Polypyridyl Complexes Into DNA Oligonucleotides by Copper‐Free Click Chemistry
No full textInternational audienceAlternative methods for the preparation of naïve libraries for SELEX experiments are in dire need, particularly when hydrophobic, bulky, and complex modification patterns are considered. Here, we explore the first steps toward the preparation of libraries equipped with ruthenium polypyridyl complexes using strain‐promoted azide‐alkyne cycloaddition (SPAAC) reactions. We demonstrated that dsDNA products can be efficiently equipped with dibenzocyclooctyne (DIBAC) moieties using a suitable modified nucleoside triphosphate and primer extension (PEX) reactions or PCR. The resulting dsDNA products can then be further modified using SPAAC and ruthenium polypyridyl complexes equipped with azide moieties, permitting the installation of >10 complexes. Finally, dsDNA can be efficiently converted into the corresponding modified ssDNA using magnetoseparation. These results offer the possibility of producing longer oligonucleotides equipped with complex modification patterns and open the way to SPAAC‐click‐SELEX methodologies
Roman-Egyptian mummy portraits and panels of gods from the Louvre: renewed historical and material knowledge
No full textInternational audienceSummation of the results of the material study conducted on the collection of Fayum portraits and panels of gods from the Louvre Museum between 2020 and 202
Towards Polyoxometalate Nanoelectronics
No full textPolyoxometalates form a large family of molecular oxide clusters of the early transition metals with unique and tunable properties (multi-redox, thermal and chemical robustness, magnetic). We review more than 30 years of experimental research on the electron transport properties of polyoxometalates devices, from thin films and self-assembled monolayers down to single-molecule junctions. We focus on the relationship between the polyoxometalate structures (structural type, nature of metals and heteroatoms, role of the counterions, redox states, electrode linkers and functional ligands) and the electronic structures of the polyoxometalate-based devices (energy positions of the molecular orbitals, energy offset at the interfaces). Then, we critically discuss the performances of polyoxometalates in nanoelectronics devices: capacitance and resistive switching memories, spintronics, quantum bits and neuromorphic devices. We conclude with a discussion about pending issues and perspectives
Hydrophobic ciprofloxacin derivatives as dual-functional photoinitiators for photocurable polylactide scaffolds in treatment of infected bone defects
No full textInternational audienceOsteomyelitis, a severe bone infection, poses significant challenges due to antibiotic resistance and limited efficacy of conventional treatments, which often rely on non-degradable carriers with burst antibiotic release. Biodegradable scaffolds with intrinsic antimicrobial functionality offer a promising alternative combining structural support, sustained therapy, and bone tissue regeneration. In this study, novel hydrophobic derivatives of the antibiotic ciprofloxacin – allylciprofloxacin (Cpf-Allyl) and vinylbenzylciprofloxacin (Cpf-VBC) – were synthesized and evaluated as photoinitiators for one- and two-photon polymerization (1PP and 2PP) of star-shaped polylactide (SS-PLA) to obtain scaffolds designed for bone regeneration. Both derivatives retained antimicrobial activity comparable to unmodified ciprofloxacin against key pathogens, including S. aureus and E. coli. Cpf-VBC demonstrated favorable photophysical properties for 2PP: 40% higher absorbance at 263 nm and lower fluorescence quantum yield (8% vs. 10% for Cpf-Allyl), approaching the efficiency of the commercial photoinitiator Bis-b. All photosensitive resins achieved high degrees of conversion (DC ≥ 60%) for the 1PP-method. In contrast, Cpf-VBC-based 2PP scaffolds showed a significantly lower DC (29 ± 4%) compared to both Cpf-Allyl-based and Bis-b-based scaffolds (~58%). However, the use of Cpf-VBC resulted in increased surface hydrophilicity of the scaffolds, as evidenced by lower water contact angles (62 ± 2°) and a higher polar component of surface energy. All fabricated scaffolds promoted the proliferation of mesenchymal stromal cells and their efficient osteogenic differentiation supported by scaffold mineralization. The scaffolds exhibited topographical and mechanical properties suitable for bone tissue engineering, with a Young’s modulus (262–377 MPa) in the range of human cancellous bone
Leaky by Design: Unlocking Polymersome Permeability Using Moderately Hydrophobic Polymer Blocks
No full textInternational audiencePolymersome nanoreactors, vesicular assemblies formed from amphiphilic block copolymers, provide a versatile platform for compartmentalized catalysis and the construction of biomimetic systems. While extensive efforts have focused on the encapsulation of enzymes within such constructs, reports of vesicles displaying intrinsic membrane permeability remain unusual. Typically, selective transport across polymersome membranes requires the incorporation of channel proteins or other porogenic components. Conversely, we herein demonstrate that polymer vesicles comprising poly(butylene oxide) as the hydrophobic segment exhibit inherent permeability to small molecules without the need for artificial machineries, possibly governed by moderate hydrophobicity of this polymer and consequently hydration of the membrane. Synthesis and detailed characterization of diblock and triblock copolymers containing poly(butylene oxide) and poly(glycidol), respectively, as hydrophobic and hydrophilic blocks are first demonstrated; the self-assembly of the chains into polymer vesicles and their inherent permeability to disparate small molecules are subsequently highlighted. Notably, we further reveal that such vesicles can be conveniently loaded with a model enzyme (horseradish peroxidase), which remains entrapped in the aqueous lumen. Using a well-established colorimetric assay, we show that the vesicles are also permeable to small-enzyme substrates and products, and therefore, the reported strategy can be applied to a wide range of enzymes and functional proteins for the design of simple permeable nanoreactors for enzyme-mediated catalysis
Time‐Programable Chiroptical Response From a Möbius Totemic Architecture
No full textInternational audienceInformation handling at the molecular level can be achieved by appropriate control of the chiroptical response of a chromophore. In this context, a dynamic Möbius aromatic π-system, embedded in a 3-type chirality totem edifice, has been investigated, targeting a time-dependant protonation control of its stereoselective winding. The mono-protonation of the so-called hexaphyrin-cyclodextrin hybrid (HCD) was therefore carried out with either stable (e.g. methanesulfonic acid) or unstable (trichloroacetic acid [TCA]) acids producing a drastic increase of the chiroptical activity resulting from a favored M-twist (d.e. ∼75%). Using TCA, the mono-protonation becomes a transient state, turning the static chiroptical response into a dynamic one whose time domain varies from minutes to hours, depending on the solvent composition or the amount of acid. More importantly, the way-back process (back deprotonation), that relies on the decomposition of the Cl3CCO2– counter-anion, was significantly accelerated by exchange with Cl–. As a result, addition and trapping of Cl– anion allows to switch between a dissipative and a static chiroptical response of the TCA induced mono-protonated species. This remarkable temporal control over a chiroptical signal paves the way for the design of Möbius-type devices for molecular encoding and signaling
Data-driven machine learning modelling for the manufacturing of the fuel electrode support in solid oxide cells
No full textInternational audienceThe industry-relevant fabrication of supports in fuel-electrode supported Solid Oxide Cells (SOCs) by tape casting typically involves a multi-stage process, demanding precise control over tape thickness and density. However, conventional SOC manufacturing processes are resource-intensive and often rely on industry/R&D unpublished knowledge and trial-and-error practices to achieve the target properties of the resulting tape. Hence, machine learning (ML) was employed for predicting the thickness and density across three distinct stages of the fabrication process: tape casting, sintering, and NiO-reduction process. Our developed ML models (e.g., Extra Trees and Ridge Regressions) demonstrate exceptional accuracy (R-2 > 0.9) for each specific prediction task. Concurrently, experimental data analysis was conducted to elucidate the impact of the manufacturing parameters on the tape properties. Our data-driven ML approach offers a pathway towards achieving precise tape property control and advancing more efficient SOC support manufacturing