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Showing 1 to 20 of 34 for “"Interphases"”.
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Dynamic mechanical analysis of graphite/epoxy composites with varied interphases
Dynamic mechanical analysis (DMA) has been used extensively to characterize polymeric materials. This thesis investigates the use of this technique to characterize composite materials. Four material systems, all having the same fiber and the same matrix material, were systematically altered with …
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Sizing and characterization of carbon fibers with aqueous water-dispersible polymeric interphases
… at Virginia Tech has shown that polymer-modified interphases can lead to increases by as much as two orders of magnitude in notched fatigue lifetime. In the present work, an apparatus was constructed to uniformly coat carbon fiber tow with water-soluble and dispersible polymers. Few such devices …
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Creation of crosslinkable interphases in polymer blends by means of novel coupling agents
The goal of the work is to study possibilities for the modification of interface in immiscible polymer blends, which determine to a large degree of the blend properties. For this purpose novel coupling agents (named SCA) containing 2-oxazoline, 2-oxazinone, and hydrosilane reactive sites have been …
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Molecular-Level Understanding of Electrochemical Reaction Mechanisms and Electrode Interphases in Metal-CFx Batteries
<p>The development of high-energy-density battery materials is crucial for applications spanning from electric vehicles to space exploration. Metal anode and conversion-type batteries provide higher specific energy compared to conventional intercalation-based systems. Among these, metal-carbon …
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Novel interphases: Synthesis, molecular orientation and grafting of liquid crystal polymers on carbon fibers
The objective of this research has been to study composite materials containing liquid crystal polymers either as matrices or in interfacial boundary zones. The fundamental point of interest here is the interfacial response that fiber surfaces can potentially induce in self ordering polymers. This …
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Characterization of the molecular structure at modified polymer surfaces and polyphenylene sulfide/copper interphases
The interphase region at modified polymer surfaces or at polymer\ metal interfaces may be critical in determining the strength and durability in adhesive applications. Methods to investigate these regions are limited however and this research has focused on the use of infrared reflection absorption …
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Characterization and Quantification of Solid Electrolyte Interphases for Composition-Functionality Relationships at Lithium Metal Electrodes
Lithium (Li) has the lowest electrochemical reduction potential and density of any metal, making it an exceptionally desirable anode material for batteries and a powerful chemical reductant. However, the reducing nature which makes Li so useful brings challenges: it is thermodynamically unstable in …
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Synthesis, characterization and modeling of interphases created between titanium dioxide nanotubes and various layers in biological, physical and mechanical systems
Science is nowadays directed towards application; however, the path from basic to applied research has been proven sometimes difficult. This is the case of the titanium dioxide nanotube layers (TNTs), discovered more than a decade ago; immediately after being reported, it has been predicted that …
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Interphase properties and their effects on the compression mechanics of polymeric composites
… to identify specific properties of two distinct interphases developed from fiber sizings and study their effect on the static and fatigue compression performance. Two different interphases, as formed by the introduction of contrasting fiber sizings, were studied in this dissertation. The …
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Concentration-Dependent Thermodynamics and Kinetics in Lithium-Metal Battery Electrolytes: Implications for Coulombic Efficiency
… such as dendrite formation and unstable interphases. This study investigates the intricate interplay between electrolytedependent thermodynamics, kinetics, and transport properties in LMBs, focusing on the concentration effects in fluoroethylene carbonate (FEC) and …
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Iterative and variational homogenization methods for filled elastomers
… firmly bonded or bonded through finite size interphases) in Gaussian rubber are first generated. These results are in turn utilized to construct approximate solutions for the nonlinear elastic response of non-Gaussian elastomers filled with a random distribution of rigid particles (again, …
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Traversing catalytic contexts for interrogation and design of carbon conversion electrocatalysts
… amidst the physical complexity of electrified interphases, both mechanistic inquiry and rational catalyst design remain challenging. In this work, we leverage concepts from fields outside of electrocatalysis to establish new strategies for both the interrogation and design of promising …
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Development of constitutive models for thin thermoelastic interphase in composite materials
… models is examined for thermally conductive interphases of different geometries—specifically, flat, circular, and wavy configurations, as well as for circular interphases in the settings of linear elasticity and thermo-elasticity. Their accuracy and efficiency are evaluated across a broad …
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Self-Assembly of Pullulan Abietate on Cellulose Surfaces
… adjacent phases is increased. The formation of interphases occurs as a consequence of the self-assembly process which governs the formation of wood. If this process was understood more thoroughly, perhaps tougher man-made, biobased composites could be prepared. To study self-assembly phenomena …
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INTERFACES IN THIN-FILM SOLID-STATE BATTERIES
… of implementing interfacial engineering on these interphases in the future for improvement of cyclability and stability of SSBs and ionic devices.
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"Examination of Several Potential ""Transformation Weakeners"" for Ceramic-Composite Interfaces"
In an effort to broaden the use of transformable interphases in ceramic composites, investigations were conducted towards identifying several displacive phase transformations which could potentially be used in composites with alumina, YAG, and/or mullite. Phase transformations were examined in four …
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Synthesis, properties, and morphology of lignin based epoxy resins
… defined phase boundaries, but rather had broad interphases. Additionally, the results of multifrequency dynamic mechanical thermal analysis showed that the lignin containing thermosets have very broad glass transition ranges which most likely were due to transitional phase inhomogeneities and …
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Surface and interphase studies of the adhesion of a siloxane- modified-polyimide coating on metals
… and Auger electron spectroscopy. Two kinds of interphases were found near the bond line of the coating/metal substrate. One was a component gradient interphase which was formed by component segregation of the BDS copolymer. The component gradient was different on different metal oxide surfaces …
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Aspects of Wood Adhesion: Applications of 13C CP/MAS NMR and Fracture Testing
… morphology existing at both types of wood-resin interphases. The formation of the IPN morphology was strongly influenced by resin molecular weight, cure temperature and the presence of solvent. A new test geometry for the evaluation of the fracture toughness of wood-adhesive bonds was developed. …
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ELECTRODEPOSITION OF POLYMER NETWORKS (EPON) AS CONFORMAL ULTRATHIN COATINGS
Functional coatings and interphases are omnipresent in modern technology and often determine the performance and lifetime of devices. For example, in solid-state energy storage devices, electrolyte-type polymeric interfaces between battery components such as the active electrode material and solid …
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