Polymeric nanomaterials are deemed to unlock the potential of therapeutics and improve their efficiency, to allow future advances in nanomedicine. Among these, sugar-based nanocapsules made of ...synthetic or natural carbohydrate-based macromolecular chains have raised significant interest in bio-applications. This review highlights physical or/and chemical techniques to construct both water- and oil-filled sugar-based nanocapsules. These include soft matter processes, such as (double) emulsification, coacervation or layer-by layer fabrication as well as more recently developed processes such as Polymerization Induced Self Assembly (PISA) or template core removal. Properties and bio-applications of glyconanocapsules (GNCs) are summarized and open challenges as well as opportunities for the future development of this field are being discussed.
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For years, Satellite Virtual Network Operators (VNOs) are a major player in the satellite communication market landscape. Typically, they repackage services leased from Satellite Network Operators ...(SNOs) to provide their customers with added-value end-to-end services. However, the level of control and visibility that Satellite VNOs have on their purchased services (and underlying resources) is limited mainly because of SNOs' protective/conservative policies and the closed nature of satellite devices. From the Satellite VNO perspective, this refrains the development of novel services and complicates the provision process of the services they offer. This paper proposes and elaborates on the concept of full virtualization of satellite Hubs that enables enhancing the level of control and visibility exposed to satellite VNOs. Analysis of the opportunities brought by this proposal is presented as well as insights on how it can be implemented.
Poly(vinyl alcohol)s (PVAs) are very popular dispersants for the construction of colloids and common shell-constituents of microcapsules but remain mostly unexplored as building blocks for the ...design of nanocapsules through nanoprecipitation or other processes. Herein, we first show that model commercial PVAs and oils can be concomitantly engaged in solvent-shifting procedures to give rise to oil-filled nanocapsules in one step. Next, we report the synthesis of precisely defined water-soluble glyco-PVAs by reversible addition−fragmentation chain transfer (RAFT) copolymerization of 6-O-vinyladipoyl-d-glucopyranose and vinyl chloroacetate and selective alcoholysis reactions. We finally demonstrate that these glycopolymers are excellent candidates for the straightforward conception of oil- and drug-filled, surface- and/or core-tagged, stealth, and degradable nanocapsules by nanoprecipitation.
In applications such as electrical transportation, most of the battery life is spent under storage. Understanding and estimating aging under storage, also named as calendar aging, is therefore a ...prerequisite for cell life prediction. This work investigates aging behavior upon storage of a commercial 15 Ah lithium-ion graphite/iron phosphate cell. Performance decline during 450 days of storage under nine stationary conditions is analyzed using non-destructive electrochemical tests. Temperature is found to be more detrimental than State of Charge (SoC). Most often, degradation models express the accumulated degradation with respect to time and aging conditions. In this article, a simple modeling approach is proposed focusing on the degradation rate to predict capacity fade. This permits predicting cell degradation under time dependent storage conditions (SoC and temperature) which are usually experienced in real applications. Model prediction is compared to experimental calendar aging data obtained over 625 days in a controlled time dependent temperature storage conditions. Predictions are in good agreement with experimental results as the absolute error on capacity prediction never exceeds 3% over 400 days and 5% over 625 days.
•C/LFP cells were submitted to 11 storage conditions during at least 450 days.•Capacity fade rate is both SoC and temperature dependant.•We model capacity fade based on aging results on nine static conditions.•Life model was validated against data obtained in time varying environments.
In this work, a simplified electrochemical and thermal model that can predict both physicochemical and aging behavior of Li-ion batteries is studied. A sensitivity analysis of all its physical ...parameters is performed in order to find out their influence on the model output based on simulations under various conditions. The results gave hints on whether a parameter needs particular attention when measured or identified and on the conditions (e.g. temperature, discharge rate) under which it is the most sensitive. A specific simulation profile is designed for parameters involved in aging equations in order to determine their sensitivity. Finally, a step-wise method is followed to limit the influence of parameter values when identifying some of them, according to their relative sensitivity from the study. This sensitivity analysis and the subsequent step-wise identification method show very good results, such as a better fitting of the simulated cell voltage with experimental data.
•Sensitivity Analysis of a multi-physics model of graphite/LiFePO4 battery.•Determination of most critical parameters for voltage and temperature simulation.•Parameters value influence on loss of capacity simulated by the model in aging mode.•Step-wise method for minimizing influence of parameters while identifying others.
•Chitosan oligosaccharides were clicked onto polycaprolactone backbones (PCL-g-COs).•Amphiphilic PCL-g-COs self-assembled in solution into core-shell micelles.•Core cross-clicked nanoparticles with ...–S–S– linker gave reduction sensitivity.•Glutathione-mediated DOX release of bioreducible PCL-g-COs micelles.
Chitosan-based amphiphilic graft copolymers are commonly obtained by modification of chitosan backbones with synthetic polymers hampering both bioactivity and biodegradability. In this work, we report the preparation of a series of chitosan oligosaccharide-grafted copolymers (PCL-g-COs) from coupling reactions between azide-pendent polycaprolactones (PCL-N3) and reducing-end alkynyl-modified chitosan oligosaccharides (COs-alkynyl). The resulting PCL-g-COs self-organized in water into nanoscale micelles (Rh<20nm) having a COs shell and a PCL core. Locking of the core-micelles structure employing a disulfide-containing bis-alkyne cross-linker resulted in the formation of nano-vehicles which can be degraded in response to physiological (redox) stimuli. This feature was advantageously exploited to preferentially release an anticancer drug, doxororubicin, in response to the intracellular glutathione level.
► Aging results of commercial graphite/LFP cells. ► Capacity loss is directly related to the storage temperature. ► Storage SOC influences the capacity loss. ► Loss of cyclable lithium is the main ...source of aging. ► Results suggest the absence of active material losses at the negative electrode.
Graphite/LFP commercial cells are stored under 3 different conditions of temperature (30°C, 45°C, and 60°C) and SOC (30%, 65%, and 100%) during up to 8 months. Several non-destructive electrochemical tests are performed at different storage times in order to understand calendar aging phenomena. After storage, all the cells except those stored at 30°C exhibited capacity fade. The extent of capacity fade strongly increases with storage temperature and to a lesser extent with the state of charge. From in-depth data analysis, cyclable lithium loss was identified as the main source of capacity fade. This loss arises from side reactions taking place at the anode, e.g. solvent decomposition leading to the growth of the solid electrolyte interphase. However, the existence of reversible capacity loss also suggests the presence of side reactions occurring at the cathode, which are less prominent than those at the anode. The analyses do not show any evidence about active-material loss in the electrodes. The cells do not suffer substantial change in internal resistance. According to EIS analysis, the overall impedance increase is 70% or less.
RAFT-made poly(ionic liquid) chains (PIL), poly(1-2-acryloylethyl-3-methylimidazolium bromide) (Poly AEmimBr), have been mixed with a ionic liquid (IL), namely butylmethylimidazolium chloride ...(C4mimCl.) The similarities in terms of structure and polarity of these molecular and macromolecular imidazolium derivatives led to homogeneous and transparent solutions. The influence of the chain molar mass and the concentration was examined through rheology investigation. It was established that the steady-shear viscosity of the solutions, and the viscoelastic properties can be finely tuned by these two parameters and by temperature. The thermal-dependence of the rheological features allowed for determining high activation energies (Ea) (around 80 kJ/mol), compared to analogous PIL aqueous solutions. Such Ea values reflect high cohesion in PIL/IL solutions, related to the formation of multiple strong interactions, such as hydrogen bonds, van der Waals forces and Coulomb interactions between ionic species. Wide-angle and small-angle X-ray scattering experiments as well as scanning electron microscopy analysis evidenced a multi-scale local homogeneity of the PIL/IL solutions, which additionally exhibit high ionic conductivity (ca. 10−3 S/cm at 30 °C), as measured by broadband dielectric spectroscopy.
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•Never described mixtures composed of poly(AEmimBr) and C4mimCl were investigated and characterized.•The rheological properties were tuned both by the molar mass and the concentration of poly(ionic liquid).•A reinforced cohesion, due to H-bonds and electrostatic interactions, was obtained within the mixtures.•High ionic conductivity can be reached, offering applicative potential notably in the field of energy devices.
Between May 2009 and March 2010, six small scale paroxysms were recorded at Stromboli volcano (Aeolian Islands, Italy). The small scale paroxysm of 21 January 2010 was the only one characterized by a ...SSE to SW dispersal direction, which allowed access for sampling of the associated bomb-dominated deposit. The quenched marginal portions of twelve bombs were used to perform density, textural and chemical analyses to define the mechanisms operating in the shallow conduit during the explosion. Whole-rock density values span a range of 1100 to 2300 kg/m3 which, using a dense rock equivalent density of 2850 kg/m3, converts to a vesicularity of 20 to 61%. The vesicle volume distribution (VVD) is unimodal, with a mode at 1.8 mm, consistent with a single bubble nucleation event followed by growth, coalescence expansion and/or densification. Crystallinity ranges from 30 to 62 vol%. Vesicle and crystal contents, however, show considerable variation, consistent with the presence of an extremely dense and degassed component in the fragmented magma. Both groundmass glasses and melt inclusions are chemically homogenous, with CaO/Al2O3 in the range 0.40-0.60. Melt inclusion volatile contents (H2O up to 0.47 wt%) are consistent with fragmentation of a shallow magma residing at a depth of about 480 m. We suggest that dense, degassed and crystal-rich magma formed a “soft” rheological plug at the top of the conduit. Under such a condition, bubbles can accumulate under the plug to slowly build the pressure to a threshold point, after which the pressure is enough to cause the fragmentation of the plug.
•Textural and chemical characterization of Strombolian bomb field products, emitted during a small scale paroxysm.•Basaltic explosions modulated by shallow system dynamics.•Degassing and densification of near-surface magma in the conduit.•Strombolian fragmentation triggered by destruction of a soft plug.
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