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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 71 for “"vinylidene"”.
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CHARACTERIZATION OF ELECTROSPRAYED POLY(VINYLIDENE FLUORIDE)/CNT NANOCOMPOSITE
PVDF, Poly(vinylidene fluoride), is a polymer that has been studied for over four decades due to its good electromechanical properties, stability, and durability in various environments. Currently, PVDF is the only commercially available piezoelectric polymer. PVDF is a polymorph, which indicates …
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Flow History - Morphology - Property Interactions in Poly(vinylidene Fluoride)
… analysis of the melt flow history of poly(vinylidene fluoride), PvF$\sb2$, in an extensional flow, film-processing geometry as well as morphological characterization and property measurements of the melt extruded films are presented.
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Surface modification of electrospun poly(vinylidene fluoride) nanofibrous microfiltration membrane
Electrospinning has gained an increasing appeal in recent years and is capable of creating sub-micron to nanoscale fibers through an electrically charged jet of polymer solution/melt. These electrospun fibers have been explored in various applications such as scaffolds for tissue engineering, drug …
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Deformation and Transformation Mechanisms of Polybutene and Poly(vinylidene Fluoride)
… of thin films of polybutene (PB) and poly(vinylidene fluoride) (PVF$\sb2$) occurs by micronecking. Finite blocks are drawn off the edge of the microneck depending upon the orientation of the original crystalline lamellae comprising the spherulites with respect to the draw direction. …
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Manufacturing of Poly(vinylidene fluoride) and Evaluation of its Mechanical Properties
Poly(vinylidene fluoride) (PVDF) receives an increasing amount of attention because it exhibits the strongest piezoelectric response of any commercially available polymer. These piezoelectric properties have proved useful as actuators and sensors. Current manufacturing processes limit PVDF to thin …
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The adsorption of vinyl chloride and vinylidene chloride monomers on their polymers
… vapour adsorbed on polyvinyl chloride; (b) Vinylidene chloride monomer vapour adsorbed on polyvinyl chloride; (c) Vinylidene chloride monomer vapour adsorbed on polyvinylidene chloride; it became evident that, for a number of reasons detailed in the text, it would be worthwhile to study …
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Temperature dependent structure and properties of crystalline poly(vinylidene fluoride) from molecular simulation
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1996.
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The development of poly(vinylidene fluoride) piezoelectric sensors for measuring peel stresses in adhesive joints
… a more versatile measurement technique, poly(vinylidene fluoride) film was used to develop piezoelectric stress sensors. The sensitivities of the film to normal stresses in the three principal material directions of the orthotropic film were accurately measured using a charge amplifier and a …
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Development and characterization of a hydrogen peroxide sensor using catalase immobilized on a pyroelectric poly(vinylidene fluoride) film
… channel with a pyroelectric polymer film, poly(vinylidene fluoride) or PVDF. The sample is introduced into the flow channel using flow injection analysis technology. The heat from the reaction causes the pyroelectric material to produce an electrical potential proportional to the change in …
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Investigation of Phase Morphology and Blend Stability in Ionomeric Perfluorocyclobutane (PFCB)/Poly(vinylidene difluoride) (PVDF) Copolymer Blend Membranes
… ionomeric perfluorocyclobutane (PFCB)/poly(vinylidene difluoride) (PVDF) copolymer blend membranes. The morphologies of these unique materials, designed as proton exchange membranes (PEMs) for proton exchange membrane fuel cells (PEMFCs), have been examined not only in the …
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Study of the miscibility, morphology, crystallization, and melting behavior of blends of poly(3-hydroxybutyrate) and poly(vinylidene fluoride)
… optical, and spectroscopic studies on poly(vinylidene fluoride)/poly(3-hydroxybutyrate) (PVDF/PHB) blends prepared by melt and solution blending techniques. The blends exhibit - a single, composition dependent Tg. Dynamic crystallization studies indicate that PVDF crystallizes first in all …
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Characterization of Sulfonated Perfluorocyclobutane /Poly(Vinylidene Difluoride)-co-Hexafluoropropylene (PFCB/PVDF-HFP) Blends for Use as Proton Exchange Membranes
The research herein focuses on the characterization of a PFCB/PVDF-HFP (70:30 wt:wt) blend fuel cell membrane including the constitutive and morphological properties, how these properties predict the stresses incurred under fuel cell operating conditions, and how these properties change over time …
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Spectroscopic investigations of the X and A state dynamics of ¹³C₂H₂
… in order to further understand the acetylene - vinylidene isomerization process in the ground electronic state. Acetylene exemplifies one of the simplest bond-breaking isomerization systems and it has served as a prototype for studies of large amplitude vibrational motion in molecules. The …
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Electrospinning as a Processing Method for Electroactive Polymers and Composites
… piezoelectric properties to the fibers of poly(vinylidene fluoride). Differential scanning calorimetry and infrared spectroscopy indicated a degree of control over crystalline phase in poly(vinylidene fluoride) fibers based on electrospinning conditions. An increase in dielectric constant in the …
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Influence of High Aspect Ratio Nanoparticle Filler Addition on Piezoelectric Nanocomposites
… PNGs formed from piezoelectric copolymers poly(vinylidene fluoride-co-hexafluropropylene) or poly(vinylidene fluoride-co-trifluoroethylene) mixed with high aspect ratio zinc oxide nanowires, hydroxyl functionalized multi-walled carbon nanotubes, or carboxylic acid functionalized single walled …
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Understanding the role of kinetic parameters on the crystallization of miscible semicrystalline polymer blends
… crystalline blends of poly(pivalolactone)/ poly(vinylidene fluoride)(pPVLIPVF₂) and poly(pivalolactone)/poly(vinylidene fluoride <i>co</i>- tetrafluoroethylene)(95-5) (PPVL/P(VF2-TFE)(95-5)) prepared by solution blending. The spherulitic growth rates of the α-phase PPVL from miscible blends with …
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C-H activation: oxidative addition to an iridium(I) center and reactivity of the resulting iridium(III) species
… rearrangement of the second alkyne into a vinylidene and finally a migratory-insertion of the vinyl group unto the vinylidene to form (VIII). Complex (III) and two equivalence of 3,3-dimethyl-1-butyne produced a trans diacetylide complex (XII). The pyridyl ligand was able to remove acidic …
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