Lithium Self-Diffusion in a Polymer Electrolyte for Solid-State Batteries: ToF-SIMS/ssNMR Correlative Characterization and Modeling Based on Lithium Isotopic Labeling.

Manufacturers aim to commercialize efficient and safe batteries by finding new strategies. Solid-state electrolytes can be seen as an opportunity to develop batteries with a high energy density. They allow the use of lithium foil as the anode, increasing the energy density.

Lithium isotope tracing in silicon-based electrodes using solid-state MAS NMR: a powerful comprehensive tool for the characterization of lithium batteries.

The introduction of lithiated components with different Li/Li isotopic ratios, also called isotopic tracing, can give access to better understanding of lithium transport and lithiation processes in lithium-ion batteries. In this work, we propose a simple methodology based on high-resolution solid-state NMR for the determination of the Li/Li ratio in silicon electrodes following different strategies of isotopic tracing. The Li and Li MAS NMR experiments allow obtaining resolved spectra whose spectral components can be assigned to different moieties of the materials.

(De)Lithiation and Strain Mechanism in Crystalline Ge Nanoparticles.

Germanium is a promising active material for high energy density anodes in Li-ion batteries thanks to its good Li-ion conduction and mechanical properties. However, a deep understanding of the (de)lithiation mechanism of Ge requires advanced characterizations to correlate structural and chemical evolution during charge and discharge. Here we report a combined X-ray diffraction (XRD) and Li solid-state NMR investigation performed on crystalline germanium nanoparticles (c-Ge Nps) based anodes during partial and complete cycling at C/10 Li metal.

Two-step immobilization of metronidazole prodrug on TEMPO cellulose nanofibrils through thiol-yne click chemistry for in situ controlled release.

Nowadays, drug encapsulation and drug release from cellulose nanofibrils systems are intense research topics, and commercial grades of cellulose nanomaterials are currently available. In this work we present an ester-containing prodrug of metronidazole that is covalently bound to cellulose nanofibrils in aqueous suspension through a two-step immobilization procedure involving green chemistry principles. The presence of the drug is confirmed by several characterization tools and methods such as Raman spectroscopy, elemental analysis, Dynamic Nuclear Polarization enhanced NMR.

Advanced characterization of regioselectively substituted methylcellulose model compounds by DNP enhanced solid-state NMR spectroscopy.

Dynamic Nuclear Polarization MAS NMR is introduced to characterize model methylcellulose ether compounds at natural isotopic abundance. In particular an approach is provided to determine the position of the methyl ether group within the repeating unit. Specifically, natural abundance C-C correlation experiments are used to characterize model 3-O-methylcellulose and 2,3-O-dimethylcellulose, and identify changes in chemical shifts with respect to native cellulose.

Input of solid-state C NMR to study permeation of wet archaeological bones by dicarboxylic fatty diacid-based chemicals.

Conservation treatment of degraded archaeological osseous materials is still an open challenge, since no specific conservation protocol is currently available for restorers or museum curators. This work aims to test the efficiency of two original consolidant solutions in consolidating archaeological material. Archaeological osseous materials remain rare and sparsely available, it is a real drawback for optimization of conservation treatments, therefore in the present work a set of representative samples was chosen.

Cellulose phosphorylation comparison and analysis of phosphorate position on cellulose fibers.

Chemical modifications of cellulose fibers as pretreatment for cellulose nanofibrils (CNF) production have been investigated to improve the production process and the quality of obtained cellulosic nanomaterial. In this study, phosphorylation of cellulose fibers was done in anticipation of a future nanofibrillation. Different phosphate salts, namely NHHPO, (NH)HPO, NaHPO, NaHPO and LiHPO with different constants of solubility (Ks) were used to increase the efficiency of the modification.

Coexistence of three types of sodium motion in double molybdate NaSc(MoO): Na and Sc NMR data and ab initio calculations.

The rechargeable Na-ion batteries attract much attention as an alternative to the widely used but expensive Li-ion batteries. The search for materials with high sodium diffusion is important for the development of solid state electrolytes. We present the results of experimental and ab initio studies of the Na-ion diffusion mechanism in Na9Sc(MoO4)6.

Gelled Electrolyte Containing Phosphonium Ionic Liquids for Lithium-Ion Batteries.

In this work, new gelled electrolytes were prepared based on a mixture containing phosphonium ionic liquid (IL) composed of trihexyl(tetradecyl)phosphonium cation combined with bis(trifluoromethane)sulfonimide [TFSI] counter anions and lithium salt, confined in a host network made from an epoxy prepolymer and amine hardener. We have demonstrated that the addition of electrolyte plays a key role on the kinetics of polymerization but also on the final properties of epoxy networks, especially thermal, thermo-mechanical, transport, and electrochemical properties. Thus, polymer electrolytes with excellent thermal stability (>300 °C) combined with good thermo-mechanical properties have been prepared.

Evidence of Organic Luminescent Centers in Sol-Gel-Synthesized Yttrium Aluminum Borate Matrix Leading to Bright Visible Emission.

Yttrium aluminum borate (YAB) powders prepared by sol-gel process have been investigated to understand their photoluminescence (PL) mechanism. The amorphous YAB powders exhibit bright visible PL from blue emission for powders calcined at 450 °C to broad white PL for higher calcination temperature. Thanks to C labelling, NMR and EPR studies show that propionic acid initially used to solubilize the yttrium nitrate is decomposed into aromatic molecules confined within the inorganic matrix.

Perylene-Based All-Organic Redox Battery with Excellent Cycling Stability.

Organic materials derived from biomass can constitute a viable option as replacements for inorganic materials in lithium-ion battery electrodes owing to their low production costs, recyclability, and structural diversity. Among them, conjugated carbonyls have become the most promising type of organic electrode material as they present high theoretical capacity, fast reaction kinetics, and quasi-infinite structural diversity. In this letter, we report a new perylene-based all-organic redox battery comprising two aromatic conjugated carbonyl electrode materials, the prelithiated tetra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi6) as negative electrode material and the poly(N-n-hexyl-3,4,9,10-perylene tetracarboxylic)imide (PTCI) as positive electrode material.

Solid-State NMR and DFT Combined for the Surface Study of Functionalized Silicon Nanoparticles.

Silicon nanoparticles (NPs) serve a wide range of optical, electronic, and biological applications. Chemical grafting of various molecules to Si NPs can help to passivate their reactive surfaces, "fine-tune" their properties, or even give them further interesting features. In this work, (1) H, (13) C, and (29) Si solid-state NMR spectroscopy has been combined with density functional theory calculations to study the surface chemistry of hydride-terminated and alkyl-functionalized Si NPs.

The structural organization of seed oil bodies could explain the contrasted oil extractability observed in two rapeseed genotypes.

The protein, phospholipid and sterol composition of the oil body surface from the seeds of two rapeseed genotypes was compared in order to explain their contrasted oil extractability. In the mature seeds of oleaginous plants, storage lipids accumulate in specialized structures called oil bodies (OBs). These organelles consist of a core of neutral lipids surrounded by a phospholipid monolayer in which structural proteins are embedded.

Comparative biodistribution in mice of cyanine dyes loaded in lipid nanoparticles.

Two near infrared cyanine dyes, DiD (1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine perchlorate) and ICG (Indocyanine Green) were loaded in lipid nanoparticles (LNP). DiD-LNP and ICG-LNP presented similar physicochemical characteristics (hydrodynamic diameter, polydispersity, zeta potential), encapsulation efficiency, and colloidal stability when stored in PBS buffer. However, whereas DiD had similar biodistribution than cholesteryl-1-(14)C-oleate ([(14)C]CHO, a constituent of the nanoparticle used as a reference radiotracer), ICG displayed a different biodistribution pattern, similar to that of the free dye, indicative of its immediate leakage from the nanovector after blood injection.

In vivo measurement of the size of oil bodies in plant seeds using a simple and robust pulsed field gradient NMR method.

An easy to implement and convenient method to measure the mean size of oil bodies (OBs) in plant seeds is proposed using a pulsed field gradient nuclear magnetic resonance (PFGNMR) approach. PFGNMR is a well-known technique used to study either free or restricted diffusion of molecules. As triacylglycerols (TAG) are confined in OBs, analysis of their diffusion properties is a well-suited experimental approach to determine OB sizes.

Fossil wood from the Miocene and Oligocene epoch: chemistry and morphology.

Fossil wood is the naturally preserved remain of the secondary xylem of plants that lived before the Holocene epoch. Typically, fossil wood is preserved as coalified or petrified and rarely as mummified tissue. The process of fossilization is very complex and it is still unknown why in the same fossil record, wood can be found in different fossilisation forms.

Untangling the condensation network of organosiloxanes on nanoparticles using 2D (29)Si-(29)Si solid-state NMR enhanced by dynamic nuclear polarization.

Silica (SiO2) nanoparticles (NPs) were functionalized by silanization to produce a surface covered with organosiloxanes. Information about the surface coverage and the nature, if any, of organosiloxane polymerization, whether parallel or perpendicular to the surface, is highly desired. To this extent, two-dimensional homonuclear (29)Si solid-state NMR could be employed.

Optimization of an absolute sensitivity in a glassy matrix during DNP-enhanced multidimensional solid-state NMR experiments.

Thanks to instrumental and theoretical development, notably the access to high-power and high-frequency microwave sources, high-field dynamic nuclear polarization (DNP) on solid-state NMR currently appears as a promising solution to enhance nuclear magnetization in many different types of systems. In magic-angle-spinning DNP experiments, systems of interest are usually dissolved or suspended in glass-forming matrices doped with polarizing agents and measured at low temperature (down to ∼100K). In this work, we discuss the influence of sample conditions (radical concentration, sample temperature, etc.

Solid-state NMR on bacterial cells: selective cell wall signal enhancement and resolution improvement using dynamic nuclear polarization.

Dynamic nuclear polarization (DNP) enhanced solid-state nuclear magnetic resonance (NMR) has recently emerged as a powerful technique for the study of material surfaces. In this study, we demonstrate its potential to investigate cell surface in intact cells. Using Bacillus subtilis bacterial cells as an example, it is shown that the polarizing agent 1-(TEMPO-4-oxy)-3-(TEMPO-4-amino)propan-2-ol (TOTAPOL) has a strong binding affinity to cell wall polymers (peptidoglycan).

Enhanced solid-state NMR correlation spectroscopy of quadrupolar nuclei using dynamic nuclear polarization.

By means of a true sensitivity enhancement for a solid-state NMR spectroscopy (SSNMR) experiment performed under dynamic nuclear polarization (DNP) conditions, corresponding to 4-5 orders of magnitude of time savings compared with a conventional SSNMR experiment, it is shown that it is possible to record interface-selective (27)Al-(27)Al two-dimensional dipolar correlation spectra on mesoporous alumina, an advanced material with potential industrial applications. The low efficiency of cross-polarization and dipolar recoupling for quadrupolar nuclei is completely negated using this technique. The important presence of pentacoordinated Al has not only been observed, but its role in bridging interfacial tetra- and hexacoordinated Al has been determined.

Quenching dynamics in CdSe nanoparticles: surface-induced defects upon dilution.

We have analyzed the decays of the fluorescence of colloidal CdSe quantum dots (QDs) suspensions during dilution and titration by the ligands. A ligand shell made of a combination of trioctylphosphine (TOP), oleylamine (OA), and stearic acid (SA) stabilizes the as-synthesized QDs. The composition of the shell was analyzed and quantified using high resolution liquid state 1H nuclear magnetic resonance (NMR) spectroscopy.

Compensated second-order recoupling: application to third spin assisted recoupling.

We consider the effect of phase shifts in the context of second-order recoupling techniques in solid-state NMR. Notably we highlight conditions leading to significant improvements for the Third Spin Assisted Recoupling (TSAR) mechanism and demonstrate the benefits of resulting techniques for detecting long-distance transfer in biomolecular systems. The modified pulse sequences of PAR and PAIN-CP, Phase-Shifted Proton Assisted Recoupling (AH-PS-PAR) and Phase-Shifted Proton-Assisted Insensitive Nuclei Cross Polarization (ABH-PS-PAIN-CP), still rely on cross terms between heteronuclear dipolar couplings involving assisting protons that mediate zero-quantum polarization transfer between low-γ nuclei ((13)C-(13)C, (15)N-(15)N, (15)N-(13)C polarization transfer).

Preparation and characterization of highly stable lipid nanoparticles with amorphous core of tuneable viscosity.

Lipid nanoparticles (LNP) have been designed based on low cost and human-use approved excipients, and manufactured by an easy, robust, and up-scalable process. Fluid colloidal dispersions or gel viscous formulations of highly stable nanoparticles (more than 12 month stability is achieved for some formulations) can be obtained. Their physicochemical properties are studied by Dynamic Light Scattering, Differential Scanning Calorimetry, and NMR.

Exposure of biological preparations to radiofrequency electromagnetic fields under low gravity.

There is interest as to whether the electromagnetic fields used in mobile radiotelephony might affect biological processes. Other weak fields such as gravity intervene in a number of physical and biological processes. Under appropriate in vitro conditions, the macroscopic self-organization of microtubules, a major cellular component, is triggered by gravity.