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Piezospectroscopic Calibration of Alumina-Nanocomposites for the Development of Stress-Sensing StructuresFugon-Dessources, Daniela 01 January 2014 (has links)
Alpha-alumina is known to exhibit photo-luminescent (PL) properties, mainly characteristic R-lines that shift according to applied stress. In addition to showing excellent PL properties, polymers with embedded alumina nanoparticles have been shown to improve the overall composite mechanical properties. While the use of the PL properties to develop stress-sensing materials using an alumina-epoxy material has been success- fully shown in compression, the properties have not been developed for tension. In this study, the PL response of variable volume fraction alumina-epoxy composites will be determined under tensile conditions. It is expected that increasing the volume fraction of alumina nanoparticles will increase the sensitivity of the particles PL emission shift to applied stress. Three tensile alumina-epoxy specimens of 21.0%, 31.2%, and 34.5% volume fractions were manufactured and tested under tensile static loads. The results of this experiment will determine the piezospectroscopic (PS) coeffi cient and calibration of bulk alumina nanocomposites in tension. A linear region was identified in the PS response of the nanocomposite to the applied tensile load. The PS coeffi cient of this linear region increased as the volume fraction of the nanocomposite increased. To demonstrate the application of structural composites with stress sensing capabilities, alumina nanoparticles were integrated in the manufacturing of a carbon fiber composite specimen. The results of the stress-sensing composite mechanical experiment showed that alumina nanoparticles were able to detect changes in stress. The results for both the bulk nanocomposite calibrations and the application of stress-sensing alumina nanoparticles in a carbon-fiber composite will advance the development of this novel stress-sensing method.
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Cyanate Ester, Epoxy And Epoxy/Cyanate Ester Matrix Polyhedral Oligomeric Silsesquioxane NanocompositesLiang, Kaiwen 10 December 2005 (has links)
Cyanate ester (PT-15, Lonza Corp) composites containing the inorganic-organic hybrid polyhedral oligomeric silsesquioxanes (POSS), octaaminophenyl(T8)POSS (C6H4NH2)8(SiO1.5)8, cyanopropylheptacyclopentyl(T8)POSS, (C5H9)7(SiO1.5)8(CH2) 3CN or TriSilanolPhenylPOSS (C42H38O12Si7), were synthesized respectively. These PT-15/POSS composites were characterized by FT-IR, X-ray diffraction (XRD), small-angle neutron scattering (SANS), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (X-EDS), transmission electron microscopy (TEM), dynamic mechanical thermal analysis (DMTA) and three-point bending flexural tests. XRD, TEM and IR data are all consistent with molecular dispersion of octaaminophenyl(T8)POSS and TriSilanolPhenylPOSS due to the chemical bonding of the POSS macromer into the continuous cyanate ester network phase. In contrast to octaaminophenyl(T8) POSS and TriSilanolPhenylPOSS, cyanopropylheptacyclopentyl (T8)POSS has a low solubility in PT-15 and does not react with the resin before or during the cure. The TriSilanolPhenylPOSS (C42H38O12Si7) was incorporated into the aliphatic epoxy (Epoxy 9000, Clearstream Products, Inc.) in 99/1, 97/3, 95/5, 90/10 and 85/15 w/w ratios and cured. This same epoxy resin was also blended with an equal weight (50/50 w/w) of cyanate ester resin (PT-15, Lonza Corp) and TriSilanolPhenylPOSS was added in resin/POSS weight ratios of 99/1, 97/3, 95/5, 90/10 and 85/15 and cured. Both sets of composites were characterized by FT-IR, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (X-EDS), dynamic mechanical thermal analysis (DMTA) and three-point bending flexural tests. TriSilanolPhenyl-POSS was first thoroughly dispersed into the uncured liquid epoxy resin or the epoxy/PT-15 blend. XRD and X-EDS measurements after curing were consistent with partial molecular dispersion of the POSS units in the continuous matrix phase, while the remainder forms POSS aggregates. TEM and SEM show that POSS?enriched nanoparticles are present in the matrix resins of both the epoxy/POSS and epoxy-PT-15/POSS composites.
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Characterization and Analysis of Graphite Nanocomposites for Thermal Management of ElectronicsMahanta, Nayandeep Kumar January 2009 (has links)
No description available.
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Novel Approaches For Nanocomposites Preparation and CharacterizationZhang, Xiao 10 June 2014 (has links)
No description available.
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Sustainable Polycarbonate Nanocomposites: Impact of Production Method and CompositionZhang, Wei January 2014 (has links)
No description available.
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Synthesis and Characterization of Crosslinked Polyurethane-Clay NanocompositesPeng, Shirley 30 June 2015 (has links)
No description available.
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Percolation Modeling in Polymer NanocompositesBelashi, Azita 24 May 2011 (has links)
No description available.
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Synthesis and properties of polyimide/organo clay and polyimide/polyaniline-modified clay nanocompositesWang, Jia 06 December 2010 (has links)
No description available.
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Synthesis, Structure And Properties Of Polymer NanocompositesZeng, Changchun 04 March 2004 (has links)
No description available.
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Rheology of polymeric suspensions: polymer nanocomposites and waterborne coatingsXu, Jianhua 02 December 2005 (has links)
No description available.
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