Small-angle X-ray Scattering Measurements Research Articles

Tensile and structural properties of natural rubber vulcanizates with different mastication times

Mastication reduced the molecular weight of natural rubber (NR). This would affect the tensile properties and strain-induced crystallization of the rubber vulcanizates due to the structural changes of the rubber molecules. In this study, influences of mastication time on tensile response, deformation-induced crystallization, and structural effects of crosslinked NR were investigated. The crystallization behavior and structural changes during stretching were studied by means of wide angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS). Increased mastication time significantly affected modulus at specified strain and upturn point of strain-induced crystallization of the crosslinked samples while the tensile strength was influenced slightly by mastication. During stretching, degree of crystallinity at given strain was found to decrease with increasing mastication time, while the crystallite size was reduced. Moreover, the size of crosslinked network structures induced by crosslinking also decreased slightly with increasing mastication time, as suggested by SAXS measurement.

Clustering in Ferronematics - The Effect of Magnetic Collective Ordering

Clustering of magnetic nanoparticles can dramatically change their collective magnetic properties and it consequently may influence their performance in biomedical and technological applications. Due to tailored surface modification of magnetic particles such composites represent stable systems. Here, we report ferronematic mixtures that contain anisotropic clusters of mesogen-hybridized cobalt ferrite nanoparticles dispersed in liquid crystal host studied by different experimental methods - magnetisation measurements, small angle X-ray scattering (SAXS), small angle neutron scattering (SANS) and capacitance measurements. The obtained results showed non-monotonic dependencies of magnetisation curves as well as of the Freedericksz transition on the magnetic nanoparticles concentration. This can be explained by the formation of clusters, whose structure was determined by SAXS measurements. Complementary to the magnetisation measurements, SANS measurements of the samples were performed for different magnetic field strength to obtain information on the orientation of the liquid crystal molecules.

Improvement of Small-angle X-ray Scattering Measurement at BL40B2

Improvement of Small-angle X-ray Scattering Measurement at BL40B2

Effects of Asymmetric Molecular Architecture on Chain Stretching and Dynamics in Miktoarm Star Copolymers

We use broad-band dielectric spectroscopy (BDS) and small-angle X-ray scattering (SAXS) to investigate the impact of architectural asymmetry in the miktoarm star copolymer on the dielectric polymer relaxations. The miktoarm copolymers studied contain one or two polystyrene (PS) chains of constant molecular weight and two identical poly(cis-1,4-isoprene) (PI) chains with varied molecular weights. Using the chains in the PI block as dielectric probes, we find that the architecturally asymmetric miktoarm star copolymer systems (PSPI2) feature distributions in chain relaxation times and dielectric relaxation strengths that are not dependent on molecular weight or morphology, in stark contrast to the effects of morphological confinement observed for symmetric diblock systems (PS-b-PI or PS2PI2). Along with evidence from the SAXS measurements regarding phase separation, these results are attributed to influences from chain stretching within the framework of the Gaussian chain model for block copolymer systems. As such, the molecular architecture in block copolymers happens to be a versatile handle to control polymer chain dynamics and, ultimately, the macroscopic physicochemical properties in architecturally complex polymers.

A Synchrotron in situ X-ray Study on the Multiple Melting Behaviors of Isomorphous Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(HB-co-HV)) with Middle HV Content

The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB-co-HV)] with the middle HV content of 19.4 mol% and 28.7 mol% were confirmed by differential scanning calorimetry (DSC), and the evolutions of crystal structure and lamellar morphology in the heating and melting process were tracked by in situ synchrotron wide angle X-ray diffraction (WAXD) and small angle X-ray scattering (SAXS) techniques. The emergence of asymmetric features of both the diffraction peaks and scattering curves indicates the coexistence of different lamellar crystals with varied unit cell parameters. Based on the in situ WAXD and SAXS measurements, we calculated the evolutions of the unit cell parameters a and b as well as the long period and lamellar thickness upon heating. The comparative analysis of WAXD and SAXS data confirms that the multiple endothermic peaks of P(HB-co-19.4%HV) and P(HB-co-28.7%HV) result from the melting of different lamellae rather than the melting/recrystallization. The thinner, unstable uniform lamellae with HV counits total inclusion melt first and the thicker, stable sandwich lamellae with HV counits partial inclusion melt last. In addition, the large second melting peak in P(HB-co-19.4%HV), differing from that of samples with HV content of 28.7 mol% and 36.2 mol%, is due to the unique state of HV content leading to a transition of sandwich lamellae to uniform lamellae. The present study establishes the relationship between the different lamellae structure and multiple melting behaviors of isomorphous copolymer.

The presence of iron oxide nanoparticles in the food pigment E172

Iron oxides used as food colorants are listed in the European Union with the number E172. However, there are no specifications concerning the fraction of nanoparticles in these pigments.Here, seven E172 products were thoroughly characterized. Samples of all colors were analyzed with a broad spectrum of methods to assess their physico-chemical properties. Small-Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), zeta-potential, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), X-ray diffraction (XRD), Brunauer-Emmett-Teller analysis (BET), Asymmetric Flow Field-Flow Fractionation (AF4) and in vitro cell viability measurements were used.Nanoparticles were detected in all E172 samples by TEM or SAXS measurements. Quantitative results from both methods were comparable. Five pigments were evaluated by TEM, of which four had a size median below 100 nm, while SAXS showed a size median below 100 nm for six evaluated pigments. Therefore, consumers may be exposed to iron oxide nanoparticles through the consumption of food pigments.

Mechanistic insights on ultra-tough polylactide-based ionic nanocomposites

We report the synthesis and characterization of ultra-tough polylactide-based ionic nanocomposites via melt-blending of commercial polylactide (PLA), imidazolium-functionalized poly(ethylene glycol)-based polyurethane (im-PU) and surface-modified sulfonated silica nanoparticles (SiO2–SO3H) using extrusion techniques. The proximity of bulky pendant imidazolium cationic sites attached onto the highly functionalized polyurethane to the anionic sulfonate groups at the silica nanoparticle surface readily allow maximizing dynamic ionic interactions within the resulting PLA-based materials. This new design leads to a unique property profile that combines ultra-toughness (no break) and ductility (up to 150%), without critical loss of stiffness as well as improved thermal stability (up to 40 °C higher compared to neat PLA). In addition, we present a detailed mechanistic study aiming at elucidating the energy-dissipative toughening in these PLA/im-PU/SiO2–SO3H blends under quasi-static and high-speed loadings (ca. impact, tensile, 3-points bending). Relying on Small-Angle X-Ray Scattering (SAXS), creep and rheological measurements, a toughening mechanism is finally proposed to account for the impact behavior of the resulting ionic nanocomposites.

Structure-Function Investigation of Haemophilus Influenzae Ferric Binding Protein under Changing Environmental Conditions

FbpA is an iron transport protein from the pathogenic bacteria, Haemophilus Influenzae, which hijacks one iron from human Transferrin (Tf) and transports it through the periplasmic space of the organism. It has 309 residues, and contains an iron binding cleft with two tyrosines, one histidine and one glutamic acid residues. Iron is held in the cleft by the octahedral coordination of these residues and a phosphate which serves as a synergistic anion. In this study, we investigated the significance of pH and ionic strength (IS) on the iron binding and release dynamics of H. influenzae ferric binding protein (FbpA) through binding/release assays as well as from a structural perspective. FbpA was expressed, purified and characterized in large quantities. Size Exclusion Chromatography (SEC), Dynamic Light Scattering (DLS), UV-Vis Absorption Spectroscopy (AS) and Small Angle X-ray Scattering (SAXS) were used for detecting structural changes. SAXS measurements were used to compare solution structures with the crystal structures, as well as to detect the changes in protein conformations under different environmental conditions. Additionally, absorbance values at 480 nm due to metal-to-ligand charge transfer caused by the interaction of tyrosine residues with the iron were monitored for investigation of iron binding dynamics under different IS conditions. Our results show that both apo and holo FbpA have flexible structures in solution with the former being slightly more open compared to the latter and both forms are more stable at high IS. Results are consistent with the closing of the iron binding pocket, when iron is captured, resulting in a decrease in hydrodynamic radius and radius of gyration. It is proposed that low IS can lead to instabilities in the protein structure and expose the bound iron to chelators at the inner membrane.

Microstructure Analysis of Graded Interface Layers in a Model Multilayer Al/Al–Zn/Al Sample by Scanning Microbeam Small-Angle X-ray Scattering Measurements

Microstructure Analysis of Graded Interface Layers in a Model Multilayer Al/Al–Zn/Al Sample by Scanning Microbeam Small-Angle X-ray Scattering Measurements

Effect of iPP molecular weight on its confinement within mesoporous SBA-15 silica in extruded iPP−SBA-15 nanocomposites

Different nanocomposites based on two isotactic polypropylenes (iPP) and mesoporous SBA-15 silica have been attained by melt extrusion as an attempt to understand the influence of average molecular weight in the rheological behavior, morphological and crystalline features and in the final properties (thermal stability and mechanical response) as well as in the capability of incorporating iPP chains within the nanometric SBA-15 pores. Closeness to rheological percolation and a significant increase of viscosity are observed as SBA-15 content is raised, this effect being more evident for the materials prepared from the iPP with the lowest molecular weight. These composites also shift their maximum degradation to lower values under inert atmosphere but keep rather unchanged decomposition behavior in oxidant conditions. No considerable changes are found with molecular weight in their morphological characteristics, nor in the type of iPP polymorph developed. The confinement of iPP chains in the SBA-15 channels, implied by a small endotherm in the DSC melting curves, is definitely ascertained by real-time variable-temperature Small Angle X-ray Scattering measurements with synchrotron radiation, suggesting, additionally, that somewhat thicker crystallites are developed within the mesostructure in the materials prepared from the iPP with inferior molecular weight. Moreover, the SBA-15 mesoporous particles exert a reinforcing role in all cases and reduce the deformation capacity of the ultimate materials as their content is increased. • Uniform and random distribution of SBA-15 within iPP occurs, independently of iPP molecular weight, M w . • Reinforcement in molten state is more important at high SBA-15 contents in iPPL, i.e. , as M w decreases. • Rigidity in the bulk is also superior for the iPPL based materials because of their higher crystallinity. • DSC endotherm and SAXS discontinuity from iPP confinement show a shift at lower temperatures in iPPH composites.

Biomimetic Color-Changing Hierarchical and Gradient Hydrogel Actuators Based on Salt-Induced Microphase Separation.

There have been more challenges for hydrogel actuators to meet the combined requirement of discoloration, complex deformation, and simple preparation. Structural coloration is widely used to fabricate discolored hydrogel via microrearrangement of photonic crystals in the hydrogel framework. However, precise regulation is usually required. Besides, the macro-optical properties are unstable. Herein, we develop a hierarchical and gradient hydrogel actuator with complex deformation and color-changing functions using an electrophoresis method. A simple but effective strategy is presented for fabrication of hierarchical hydrogel composed of homopolymers and copolymers via salt-induced microphase separation during the polymerization of the N-isopropylacrylamide (NIPAm) and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (DMC). Meanwhile a gradient distribution of DMC is also formed during the polymerization due to migration of DMC under electric field. The hierarchical and gradient structures are characterized by confocal laser scanning microscope (CLSM), small-angle X-ray scattering measurement (SAXS), temperature-variable Fourier transform infrared (FTIR), etc. The discoloration mechanism is proposed. The as-prepared hydrogel can undergo fast and complex thermo-triggered deformation and discoloration. Bionic movements of discoloration flowering and information encryption are successfully demonstrated, promising great potential in the application of biomimetic materials.

Thermally-Induced morphological evolution of spherical silica nanoparticles using in-operando X-ray scattering measurements

The assembly and morphology of pores determine thermodynamic, flow and reactive properties of confined fluids. However, there is a limited understanding of how pore architectures dynamically develop in engineered and natural materials. To develop a calibrated understanding of fluid properties in confinement, the synthesis of architected materials has been proposed. The design of geo-architected materials has to be informed by the dynamic evolution of the morphology in response to thermal or chemical events. In this study, we probe thermally induced morphological evolution of spherical silica nanoparticles 220 ± 30 nm in diameter using in-operando Ultra-Small and Small Angle X-Ray Scattering measurements. The calcination experiments demonstrated that at temperatures up to 600 °C the pore radii remained in the range of 2.15 nm–2.35 nm and the particle diameters in the range of 220 ± 30 nm. Sintering these calcined silica nanoparticles to temperatures up to 1050 °C reduced the pore size from 2.2 ± 0.1 nm to ∼1.8–0.2 nm. These changes corresponded to the formation of siloxane (Si-O-Si) bridges resulting from dehydroxylation. The characteristic pore radius of sintered particles was also confirmed by N2 adsorption measurements. These studies represent the use of non-invasive dynamic characterization methods such as X-ray scattering to elucidate thermally induced morphological evolution in architected siliceous materials.

Phase Diagrams and Structural Characterization of Mixtures of Silicone Surfactants + Silicone Oils + Water.

Silicone surfactants display unique properties and are widely employed in pharmaceutical and cosmetic products. In this work, we study water incorporation into silicone oils using silicone surfactants. Despite their importance, there are only a few studies reporting their phase equilibrium and structural characterization. Here, we determined the phase diagram of systems containing silicone oils, silicone surfactants, and water. In particular, we investigated the self-assembly behavior of two siloxane surfactants with the different hydrophilic-lipophilic balance: M(D'E7OH)M and MD18(D'3E18OAc)M and two silicone oils (cyclic oil-D4 and linear oil-MD15M). The phase behavior of the mixtures was investigated through optical inspection and structural characterization of aggregated states (microemulsions and mesophases) using small angle X-ray scattering (SAXS). These water-in-oil microemulsions or bicontinuous microemulsions incorporated a maximum amount of approximately 20 wt % water for the two surfactants with cyclic oil. A similar behavior was also identified with linear silicone oil, though with smaller water contents. We also observed the formation of anisotropic states, with a predominance of lamellar phases and a small region of a hexagonal phase. A quantitative analysis of the SAXS curves in the lamellar region reveals that this mesophase swells continuously after the addition of water lamellar periods ranging from 50 Å (with 18 wt % water) to 64 Å (with 40 wt % water). Our results confirm and expand the earlier literature on similar compounds, indicating their potential in incorporating water into silicone mixtures and forming interesting mesophases. Accompanying this characterization, we also report a comprehensive and systematic set of structural details for the different systems (microemulsions, bicontinuous phases and mesophases) formed by these mixtures, derived from the SAXS measurements.

Interdomain communication suppressing high intrinsic ATPase activity of Sse1 is essential for its co-disaggregase activity with Ssa1.

In eukaryotes, Hsp110s are unambiguous cognates of the Hsp70 chaperones, in primary sequence, domain organization, and structure. Hsp110s function as nucleotide exchange factors (NEFs) for the Hsp70s although their apparent loss of Hsp70-like chaperone activity, nature of interdomain communication, and breadth of domain functions are still puzzling. Here, by combining single-molecule FRET, small angle X-ray scattering measurements (SAXS), and MD simulation, we show that yeast Hsp110, Sse1 lacks canonical Hsp70-like interdomain allostery. However, the protein exhibits unique noncanonical conformational changes within its domains. Sse1 maintains an open-lid substrate-binding domain (SBD) in close contact with its nucleotide-binding domain (NBD), irrespective of its ATP hydrolysis status. To further appreciate such ATP-hydrolysis-independent exhaustive interaction between two domains of Hsp110s, NBD-SBD chimera was constructed between Hsp110 (Sse1) and Hsp70 (Ssa1). In Sse1/Ssa1 chimera, we observed undocking of two domains leading to complete loss of NEF activity of Sse1. Interestingly, chimeric proteins exhibited significantly enhanced ATPase rate of Sse1-NBD compared to wild-type protein, implying that intrinsic ATPase activity of the protein remains mostly repressed. Apart from repressing the high ATPase activity of its NBD, interactions between two domains confer thermal stability to Sse1 and play critical role in the (co)chaperoning function of Sse1 in Ssa1-mediated disaggregation activity. Altogether, Sse1 exhibits a unique interdomain interaction, which is essential for its NEF activity, suppression of high intrinsic ATPase activity, co-chaperoning activity in disaggregase machinery, and stability of the protein.

Hydrophilic Silver Nanoparticles Loaded into Niosomes: Physical-Chemical Characterization in View of Biological Applications.

Silver nanoparticles (AgNPs) are widely used as antibacterial agents and anticancer drugs, but often their low stability limits their mass production and broad applications. The use of niosomes as a carrier to protect and envelop AgNPs gives a new perspective to solve these problems. In this study, AgNPs were functionalized with sodium 3-mercapto-1-propanesulfonate (3MPS) to induce hydrophilic behavior, improving loading in Tween 20 and Span 20 niosomes (NioTw20 and NioSp20, respectively). Entrapment efficiency was evaluated by UV analyses and is around 1–4%. Dimensions were investigated by means of dynamic light scattering (DLS) (<2RH> = 140 ± 4 nm and <2RH> = 251 ± 1 nm respectively for NioTw20 + AgNPs and NioSp20 + AgNPs) and were compared with those by atomic force microscopy (AFM) and small angle X ray scattering (SAXS) analyses. Stability was assessed in water up to 90 days, and both in bovine serum and human serum for up to 8 h. In order to characterize the local structure of niosomes, SAXS measurements have been performed on Tween 20 and Span 20 empty niosomes and loaded with AgNPs. The release profiles of hydrophilic probe calcein and lipophilic probe Nile Red were performed in HEPES buffer and in human serum. All these features contribute to conclude that the two systems, NioTw20 + AgNPs and NioSp20 + AgNPs, are suitable and promising in the field of biological applications.

Mesomorphic, structural, electro-optic and dynamic properties of lactic acid derivative and its selectively deuterated isotopomers by means of electro-optics, SAXS, 2H-NMR and neutron spin-echo spectroscopy

ABSTRACT In this work, we present the synthesis of two analogues of a lactic acid derivative selectively deuterated on phenyl and biphenyl moieties together with a detailed investigation of their properties within the Twist Grain Boundary smectic A* (TGBA*), the ferroelectric Smectic C* (SmC*) and the crystal E phases. The main structural features of the two liquid crystalline phases, namely TGBA* and SmC* phases, were determined by polarising optical microscopy, differential scanning calorimetry, electro-optical techniques, Small Angle X-ray Scattering (SAXS) and 2H Nuclear Magnetic Resonance (2H NMR) measurements. Preliminary results from Neutron Spin-Echo (NSE) spectroscopy, a technique rarely applied to study chiral liquid crystalline materials, are reported. The effect of the external magnetic field on the supramolecular structure of the ferroelectric phase was studied by means of 2H-NMR experiments under different external magnetic fields. The supramolecular and orientational ordering properties of this ferroelectric lactic acid derivative and its deuterated homologues are discussed in the frame of actual knowledge in the field of ferroelectric liquid crystal materials.

Monitoring of the nano-structure response of natural clay under mechanical perturbation using small angle X-ray scattering and digital image correlation

This paper introduces a new experimental method to monitor the evolving intra-particle, nanometre-scale response during hydro-mechanical tests on undisturbed wet clay samples using small angle X-ray scattering (SAXS). The method uses a newly developed miniature plane-strain one-dimensional compression cell that facilitates simultaneous full-field surface displacement measurements using digital image correlation and SAXS measurements. The 60–120 s acquisition times offered by SAXS at synchrotron facilities are beneficial to study time-dependent mechanisms in clays. The experimental results presented indicate that, for the natural sensitive clay tested in this work, no significant structural changes occur at the intra-particle scale during loading, even when large strains are measured at the macro-scale. In addition, changes that are observed at this scale occur after the end of perturbation, i.e. the creation of new intra-particle structures. Further information is obtained on the orientation evolution of the fabric by the comparative analysis of the individual mineral component response.

Insights of the kolliphor/water system for the design of mesostructured silica materials

Abstract Herein, mesostructured silica materials have been prepared through the Cooperative Templating Mechanism (CTM) using kolliphor EL (KEL) as biocompatible surfactant. First, the behavior of KEL in water has been studied and the phase diagram has been determined. KEL forms micelles (L1) in water and in higher concentrations a liquid crystal domain appears, which is constituted of a cubic phase (Pm3n) and a direct hexagonal phase. Small Angle X-ray Scattering (SAXS) experiments were performed to study the structure of the Organized Molecular Systems. We show that KEL leads to spherical micelles in water, which have a radius comprised between 6.2 and 6.5 nm, depending on the surfactant concentration. Then, mesoporous materials were synthesized and characterized by SAXS measurements and nitrogen adsorption-desorption analysis. The structure of the recovered material is affected by the surfactant/silica molar ratio. Indeed, the mesopore ordering is detected only for ratios in the range between 0.017 and 0.031. As long as mesostructures are obtained, the mesopores diameters are in accordance with the dimension of the hydrophobic size of the micelles.

Accessing the Lithiation/Delithiation Mechanism of a Li-Ion Battery FeSi2/Si/Graphite Composite Negative Electrode and Differentiating the Si/Graphite Contributions By Simultaneous Operando Synchrotron SAXS/Waxs

Combined with renewable energy harvesting technologies, such as solar panels or wind turbines, energy storage is the key to keeping up with the ever-increasing demand for electric energy and reducing the world dependency on fossil fuels. Over the last three decades lithium-ion batteries (LiBs), starting with the first commercialized cell by Sony in 1990 [1], have evolved from the most promising energy-storage technologies [2] to the most widely used nowadays. Not only can LiBs be found in portable devices such as laptops, they are also used in larger scale applications such as electric vehicles. Since the first commercialization of LiBs, graphite (372 mAh.g-1) has been the usual negative electrode material. Nevertheless, the continuous demand, in the automotive industry in particular, for more performant, light, safe and cheap LiBs drives research towards the design and development of new electrode materials characterized in particular by high energy densities and a longer capacity retention during cycling. Among the candidates for high specific gravimetric capacity is silicon (3579 mAh.g-1) [3]. However, two major problems hamper the use of this material as a LiB electrode material. The first is its high volumetric change (297 % [4]) during lithiation, which causes particle cracking and pulverization during cycling which in turn leads to a quick fading of the cell capacity. The second is its high first cycle irreversible capacity. Reducing the particle size to the nanoscale and thus reducing the mechanical strain on the particle by attenuating its volumetric expansion/contraction helps alleviate pulverization. However, because of poor electrode structural stability during cycling this approach alone does not stop capacity degradation [5]. Using a dual-phase composite material that contains an inactive host matrix in which the active material is well-dispersed also alleviates pulverization. The FeSi2/Si/graphite anode material is particularly interesting due to its low-cost, high reversible capacity and good cycling stability [6]. This material is composed of a dual-phase FeSi2 (inactive)/amorphous Si (active) composite and graphite, a conductive matrix to accommodate the Si volumetric expansion, and is seen as well suited for the development of high capacity LiBs. Be that as it may, it is still unclear how this complex material functions and what makes it so performant. With the aim of accessing the lithiation/delithiation mechanism of a FeSi2/Si/graphite negative LiB electrode, we performed simultaneous operando Small and Wide Angle X-Ray Scattering (SAXS and WAXS) measurements on a cycling NMC//FeSi2/Si+graphite pouch-cell filled with a 1 mol.L-1 LiPF6 in FEC/EMC (30/70 wt%) electrolyte at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Through WAXS we were able to investigate the local structure (10-1 nm) of the cell materials and in particular observe the lithiation/delithiation of the graphite phase by following its corresponding Bragg peak and those of its different lithiated phases (LiC30, LiC24, LiC18, LiC12 and LiC6). Simultaneously, we gained information on the active silicon state of lithiation/delithiation by observing the morphology changes occurring at the nano-scale (1 nm to 10 nm) during the volumetric expansion/contraction of the silicon through SAXS measurements. The combined information give us insight on the lithiation/delithiation mechanism of the negative electrode and enabled us to dissociate the capacity contribution of the silicon phase from that of the graphite phase as a function of potential, time and capacity. By cycling the cell at several current-rates and by repeating the same experiment on an aged cell cycled 300 times, we were also able to enquire into the impact of fast-charging and ageing on the lithiation/delithiation mechanism of the negative electrode. In this talk, we will present those results after proposing a lithiation/delithiation mechanism for the FeSi2/Si/graphite composite electrode. Yoshio Nishi, H.A., Atsuo Omaru Non aqueous electrolyte cell, in US Patent1990, Sony Corp United States of America.Armand, M. and J.M. Tarascon, Building better batteries. Nature, 2008. 451: p. 652.Goriparti, S., et al., Review on recent progress of nanostructured anode materials for Li-ion batteries. Journal of Power Sources, 2014. 257: p. 421-443.Tian, H., et al., High capacity group-IV elements (Si, Ge, Sn) based anodes for lithium-ion batteries. Journal of Materiomics, 2015. 1(3): p. 153-169.Li, H., et al., A High Capacity Nano Si Composite Anode Material for Lithium Rechargeable Batteries. Electrochemical and Solid-State Letters, 1999. 2(11): p. 547-549.Li, T., et al., Cycleable graphite/FeSi6 alloy composite as a high capacity anode material for Li-ion batteries. Journal of Power Sources, 2008. 184(2): p. 473-476. Figure 1

Influence of Pluronic F127 microenvironments on the photochemical nitric oxide release from S-nitrosoglutathione

Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) (F127) hydrogels have been used to deliver nitric oxide (NO) topically in biomedical applications. Here, the effect of F127 microenvironments on the photochemical NO release from S-nitrosoglutathione (GSNO) was investigated in F127 solutions 7.6 wt% 15 wt% and 22.5 wt% at 15 °C and 37 °C. Small-angle X-ray Scattering (SAXS) and Differential Scanning Calorimetry (DSC) measurements, along with proton Nuclear Magnetic Resonance (1H NMR) spectral shifts and T2 relaxation data at six different concentration-temperature conditions, allowed identifying F127 microphases characterized by: a sol phase of unimers; micelles in non-defined periodic order, and a gel phase of cubic packed micelles. Kinetic measurements showed that GSNO photodecompositon proceeds faster in micellized F127 where GSNO is segregated to the intermicellar microenvironment. Real time kinetic monitoring of NO release and T2 relaxation profiles showed that NO is preferentially partitioned into the hydrophobic PPO cores of the F127 micelles, with the consequent decrease in its rate of release to the gas phase. These results show that F127 microphases affect both the kinetics of GSNO photodecomposition and the rate of NO escape and can be used to modulate the photochemical NO delivery from F127/GSNO solutions.