506 research outputs found
Silicon-based anode and method for manufacturing the same
A silicon-based anode comprising silicon, a carbon coating that coats the surface of the silicon, a polyvinyl acid that binds to at least a portion of the silicon, and vinylene carbonate that seals the interface between the silicon and the polyvinyl acid. Because of its properties, polyvinyl acid binders offer improved anode stability, tunable properties, and many other attractive attributes for silicon-based anodes, which enable the anode to withstand silicon cycles of expansion and contraction during charging and discharging
Laser-Induced Light Absorption in 2D Silver Nanoparticle Array
Nanocomposite comprising planar array of silver nanoparticles in polymer matrix was submitted to Ar laser irradiation at the wavelength of 488 nm. The extinction spectra of the array were measured as a function of the irradiation power density. Two collective surface plasmon modes, namely T and P, associated with particle dipoles parallel and perpendicular to the plane of the layer were identified. The extinction bands of T and P modes exhibit blue spectral shift with the increase of radiation power. P mode band
broadens when laser power increases. The observed effects are explained by heating of the nanocomposite by the intense laser radiation
Alginate-containing compositions for use in battery applications
A silicon-based anode comprises an alginate-containing binder. The many carboxy groups of alginate bind to a surface of silicon, creating strong, rigid hydrogen bonds that withstand battery cycling. The alginate-containing binder provides good performance to the anode by (1) improving the capacity of the anode in comparison to other commercially-available binders, (2) improving Columbonic efficiency during charging and discharging cycles, and (3) improving stability during charging and discharging cycles
Alginate-containing compositions for use in battery applications
A silicon-based anode comprises an alginate-containing binder. The many carboxy groups of alginate bind to a surface of silicon, creating strong, rigid hydrogen bonds that withstand battery cycling. The alginate-containing binder provides good performance to the anode by (1) improving the capacity of the anode in comparison to other commercially-available binders, (2) improving Columbonic efficiency during charging and discharging cycles, and (3) improving stability during charging and discharging cycles
Optical Properties of Multilayered Metal–Dielectric Structures Containing Silver Nanoparticles
In this paper we report on fabrication and optical properties of metal-dielectric nanostructures consisting of stacked monolayers of silver nanoparticles. The extinction spectra of the nanostructures were studied as a function of the angle of incidence and polarization state of the incident light. Two collective surface plasmon modes, namely T and P, associated with particle dipoles parallel and perpendicular to plane of the layer were identified for a single monolayer of the particles. The extinction bands of T and P modes exhibit different intensity and frequency dependences on the angle of incidence. More pronounced angular dependences for P mode band indicate the stronger coupling of dipoles for P mode than for Tone. A new N mode was observed for the structures comprising three nanoparticle layers. This new mode originated from surface plasmon coupling between adjacent layers
Magnetically Responsive Silicon Carbide Whiskers for Enhanced Nanocomposite Materials
Boeing’s 787 Dream Liner, GE’s wind turbine blades, and Ferrari’s F1 chassis demonstrate the accomplishments of designed directionality in carbon fiber/epoxy composites. The aerospace, energy and transportation industries demand composite material with enhanced multifunctional properties including ultimate strength and toughness. Despite sizeable improvements, composite utilization is limited by the fiber’s low surface-area-to-volume ratio (specific surface). Orientation in man-made composites has been the key to effective strengthening of materials under mechanical load and compensating for intrinsic limitations of the current technology. Nanocomposites can drive performance to new heights by increasing the fiber to matrix interaction. Thus far, the embedding of nanomaterials into composites has been achieved, but directional arrangement has proved to be a challenging task. Even with advances in insitu, shear, and stress orientation, these methods are both difficult to control and unreliable, hampering nanocomposite improvements. Therefore, the implementation of nanomaterials with a natural ability to orient along a magnetic field will create a controlled system with precisely designed morphology. To this end, the proposed project has develop an effective approach for the design of magnetically active nanowhiskers to form 2D aligned structures in a polymer matrix, creating novel nanocomposites with enhanced mechanical properties
Optical Properties of Multilayered Metal–Dielectric Structures Containing Silver Nanoparticles
In this paper we report on fabrication and optical properties of metal-dielectric nanostructures consisting of stacked monolayers of silver nanoparticles. The extinction spectra of the nanostructures were studied as a function of the angle of incidence and polarization state of the incident light. Two collective surface plasmon modes, namely T and P, associated with particle dipoles parallel and perpendicular to plane of the layer were identified for a single monolayer of the particles. The extinction bands of T and P modes exhibit different intensity and frequency dependences on the angle of incidence. More pronounced angular dependences for P mode band indicate the stronger coupling of dipoles for P mode than for Tone. A new N mode was observed for the structures comprising three nanoparticle layers. This new mode originated from surface plasmon coupling between adjacent layers
Surface modification of substrates
The present invention is directed to a practically universal surface modification process and the materials thereby obtained. In general, the process includes initial epoxy modification of a substrate surface by attachment of an epoxy-containing polymer to the surface. Following attachment of the polymer, still-existing epoxy groups on the polymer may then cross-link the polymer to form a unified anchoring layer on the surface. Other epoxy groups in the anchoring layer, not utilized in forming the layer may be used to graft surface modifying materials to the surface. For instance, macromolecules, biomolecules, polymers, and polymerization initiators may be grafted to the surface via the anchoring layer
Surface modification of substrates
The present invention is directed to a practically universal surface modification process and the materials thereby obtained. In general, the process includes initial epoxy modification of a substrate surface by attachment of an epoxy-containing polymer to the surface. Following attachment of the polymer, still-existing epoxy groups on the polymer may then cross-link the polymer to form a unified anchoring layer on the surface. Other epoxy groups in the anchoring layer, not utilized in forming the layer may be used to graft surface modifying materials to the surface. For instance, macromolecules, biomolecules, polymers, and polymerization initiators may be grafted to the surface via the anchoring layer
The synthesis, characterization and targeting ability of nano-scale enrichment polymer layers
Thin polymer films have been utilized as enrichment layers for evanescent waveguide chemical sensors and other analytical techniques. This is due to the fact that the chemical nature of polymers is ideal for trapping chemically similar organic molecules making analysis more convenient. Specifically, research in this area of volatile organic compounds (VOCs) detection, focused has been given to identifying a single polymer film of micron scale thickness to target one analyte. This work focuses on the design and use of multiple polymers in one enrichment layer to target VOCs to facilitate detection. Two distinct layered enrichment systems were synthesized via the “grafting to” approach. The end application is to apply these polymers onto mid-infrared transparent evanescent wave micro-disk or micro-ring resonators. Analysis of the polymer affinity to VOCs and to act as enrichment layers is determined by the thickness increase caused by swelling of the film when exposed to the analyte vapor. Detection analysis was done using attenuated total reflection (ATR) FT-IR spectroscopy. The polymer layered systems were characterized by atomic force microscopy, ellipsometry and infrared spectroscopy. Studies of pure analyte vapors and mixtures were conducted in saturated conditions
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